ORCID Profile
0000-0003-4526-4109
Current Organisations
Charles Sturt University - Orange Campus
,
Charles Sturt University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Analytical Chemistry | Sensor Technology (Chemical aspects) | Immunological and Bioassay Methods | Microelectromechanical Systems (MEMS) | Instrumental Methods (excl. Immunological and Bioassay Methods) | Additive manufacturing | Manufacturing engineering | Synthesis of Materials | Electroanalytical Chemistry | Composite and hybrid materials | Agricultural Biotechnology | Nanomaterials | Microfluidics and nanofluidics | Manufacturing Engineering | Nanotechnology | Microtechnology | Agricultural Biotechnology Diagnostics (incl. Biosensors) | Analytical Biochemistry
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in Technology | Diagnostic Methods | Control of Pests, Diseases and Exotic Species in Fresh, Ground and Surface Water Environments | Sugar | Expanding Knowledge in the Environmental Sciences | Machined Metal Products | Expanding Knowledge in the Physical Sciences | Industrial Machinery and Equipment | Expanding Knowledge in Engineering | Expanding Knowledge in the Agricultural and Veterinary Sciences | Expanding Knowledge in the Biological Sciences |
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Publications
Electrochemical detection of glycan and protein epitopes of glycoproteins in serum
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4AN00781F
Abstract: We report electrochemical interrogation of glycan and protein epitopes of the glycoprotein chicken ovalbumin spiked in diluted serum using SNA lectin and anti-ovalbumin antibody.
Electric Field Induced Isolation, Release, and Recapture of Tumor Cells
Publisher: American Chemical Society (ACS)
Date: 05-02-2016
Advances in Microfluidics‐Based Assisted Reproductive Technology: From Sperm Sorter to Reproductive System‐on‐a‐Chip
Publisher: Wiley
Date: 15-01-2018
Molecular Nanoshearing: An Innovative Approach to Shear off Molecules with AC-Induced Nanoscopic Fluid Flow
Publisher: Springer Science and Business Media LLC
Date: 16-01-2014
DOI: 10.1038/SREP03716
Large amplitude fourier transformed AC voltammetric investigation of the active state electrochemistry of a copper/aqueous base interface and implications for electrocatalysis
Publisher: American Chemical Society (ACS)
Date: 20-07-2011
DOI: 10.1021/LA2017819
Abstract: The higher harmonic components available from large- litude Fourier-transformed alternating current (FT-ac) voltammetry enable the surface active state of a copper electrode in basic media to be probed in much more detail than possible with previously used dc methods. In particular, the absence of capacitance background current allows low-level Faradaic current contributions of fast electron-transfer processes to be detected these are usually completely undetectable under conditions of dc cyclic voltammetry. Under high harmonic FT-ac voltammetric conditions, copper electrodes exhibit well-defined and reversible premonolayer oxidation responses at potentials within the double layer region in basic 1.0 M NaOH media. This process is attributed to oxidation of copper adatoms (Cu*) of low bulk metal lattice coordination numbers to surface-bonded, reactive hydrated oxide species. Of further interest is the observation that cathodic polarization in 1.0 M NaOH significantly enhances the current detected in each of the fundamental to sixth FT-ac harmonic components in the Cu*/Cu hydrous oxide electron-transfer process which enables the underlying electron transfer processes in the higher harmonics to be studied under conditions where the dc capacitance response is suppressed the results support the incipient hydrous oxide adatom mediator (IHOAM) model of electrocatalysis. The underlying quasi-reversible interfacial Cu*/Cu hydrous oxide process present under these conditions is shown to mediate the reduction of nitrate at a copper electrode, while the mediator for the hydrazine oxidation reaction appears to involve a different mediator or active state redox couple. Use of FT-ac voltammetry offers prospects for new insights into the nature of active sites and electrocatalysis at the electrode/solution interface of Group 11 metals in aqueous media.
Recent advances and current challenges in magnetophoresis based micro magnetofluidics
Publisher: AIP Publishing
Date: 05-2018
DOI: 10.1063/1.5035388
Abstract: The combination of magnetism and microscale fluid flow has opened up a new era for handling and manipulation of s les in microfluidics. In particular, magnetophoresis, the migration of particles in a magnetic field, is extremely attractive for microfluidic handling due to its contactless nature, independence of ionic concentration, and lack of induced heating. The present paper focuses on recent advances and current challenges of magnetophoresis and highlights the key parameters affecting the manipulation of particles by magnetophoresis. The magnetic field is discussed according to their relative motion to the s le as stationary and dynamic fields. The migration of particles is categorized as positive and negative magnetophoresis. The applications of magnetophoresis are discussed according to the basic manipulation tasks such as mixing, separation, and trapping of particles or cells. Finally, the paper highlights the limitations of current approaches and provides the future perspective for this research area.
Microfluidic neurotransmitters sensor in blood plasma with mediator-immobilized conducting polymer/N, S-doped porous carbon composite
Publisher: Elsevier BV
Date: 06-2020
Gold-loaded nanoporous superparamagnetic nanocubes for catalytic signal amplification in detecting miRNA
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CC04789D
Abstract: A nonenzymatic, lification-free, and sensitive method for microRNA detection is reported using Au@NPFe 2 O 3 NC nanocubes.
Biosensing made easy with PEG-targeted bi-specific antibodies
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CC01916A
Abstract: Whilst recent advances in nanotechnology have yielded many new biosensing capabilities, innovative biological attachment and detection modalities remain relatively underdeveloped.
DNA Ligase-Based Strategy for Quantifying Heterogeneous DNA Methylation without Sequencing
Publisher: Oxford University Press (OUP)
Date: 2015
DOI: 10.1373/CLINCHEM.2014.227546
Abstract: DNA methylation is a potential source of disease biomarkers. Typically, methylation levels are measured at in idual cytosine/guanine (CpG) sites or over a short region of interest. However, regions of interest often show heterogeneous methylation comprising multiple patterns of methylation (epialleles) on in idual DNA strands. Heterogeneous methylation is largely ignored because digital methods are required to deconvolute these usually complex patterns of epialleles. Currently, only single-molecule approaches, such as next generation sequencing (NGS), can provide detailed epiallele information. Because NGS is not yet feasible for routine practice, we developed a single-molecule–like approach, named for epiallele quantification (EpiQ). EpiQ uses DNA ligases and the enhanced thermal instability of short (≤19 bases) mismatched DNA probes for the relative quantification of epialleles. The assay was developed using fluorescent detection on a gel and then adapted for electrochemical detection on a microfabricated device. NGS was used to validate the analytical accuracy of EpiQ. In this proof of principle study, EpiQ detected with 90%–95% specificity each of the 8 possible epialleles for a 3-CpG cluster at the promoter region of the CDKN2B (p15) tumor suppressor gene. EpiQ successfully profiled heterogeneous methylation patterns in clinically derived s les, and the results were cross-validated with NGS. EpiQ is a potential alternative tool for characterizing heterogeneous methylation, thus facilitating its use as a biomarker. EpiQ was developed on a gel-based assay but can also easily be adapted for miniaturized chip-based platforms.
Enhanced Peroxidase Mimetic Activity of Porous Iron Oxide Nanoflakes
Publisher: Wiley
Date: 04-02-2019
Microchip and Capillary Electrophoresis Using Nanoparticles
Publisher: Wiley
Date: 27-05-2010
TLR2 on blood monocytes senses dengue virus infection and its expression correlates with disease pathogenesis
Publisher: Springer Science and Business Media LLC
Date: 23-06-2020
DOI: 10.1038/S41467-020-16849-7
Abstract: Vascular permeability and plasma leakage are immune-pathologies of severe dengue virus (DENV) infection, but the mechanisms underlying the exacerbated inflammation during DENV pathogenesis are unclear. Here, we demonstrate that TLR2, together with its co-receptors CD14 and TLR6, is an innate sensor of DENV particles inducing inflammatory cytokine expression and impairing vascular integrity in vitro. Blocking TLR2 prior to DENV infection in vitro abrogates NF-κB activation while CD14 and TLR6 block has a moderate effect. Moreover, TLR2 block prior to DENV infection of peripheral blood mononuclear cells prevents activation of human vascular endothelium, suggesting a potential role of the TLR2-responses in vascular integrity. TLR2 expression on CD14 + + classical monocytes isolated in an acute phase from DENV-infected pediatric patients correlates with severe disease development. Altogether, these data identify a role for TLR2 in DENV infection and provide insights into the complex interaction between the virus and innate receptors that may underlie disease pathogenesis.
A novel DNA binding protein-based platform for electrochemical detection of miRNA
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1AN00935D
Abstract: We present a DNA binding protein-based novel lification-free sandwich type platform assay for electrochemical detection of miRNA.
Detecting Exosomes Specifically: A Multiplexed Device Based on Alternating Current Electrohydrodynamic Induced Nanoshearing
Publisher: American Chemical Society (ACS)
Date: 31-10-2014
DOI: 10.1021/AC502082B
Abstract: Exosomes show promise as noninvasive biomarkers for cancer, but their effective capture and specific detection is a significant challenge. Herein, we report a multiplexed microfluidic device for highly specific capture and detection of multiple exosome targets using a tunable alternating current electrohydrodynamic (ac-EHD) methodology, referred to as nanoshearing. In our system, electrical body forces generated by ac-EHD act within nanometers of an electrode surface (i.e., within the electrical layer) to generate nanoscaled fluid flow that enhances the specificity of capture and also reduce nonspecific adsorption of weakly bound molecules from the electrode surface. This approach demonstrates the analysis of exosomes derived from cells expressing human epidermal growth factor receptor 2 (HER2) and prostate specific antigen (PSA), and is also capable of specifically isolating exosomes from breast cancer patient s les. The device also exhibited a 3-fold enhancement in detection sensitivity in comparison to hydrodynamic flow based assays (LOD 2760 exosomes/μL for ac-EHD vs LOD 8300 exosomes/μL for hydrodynamic flow (n = 3)). We propose this approach can potentially have relevance as a simple and rapid quantification tool to analyze exosome targets in biological applications.
Nanoarchitectured peroxidase-mimetic nanozymes: mesoporous nanocrystalline α- or γ-iron oxide?
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TB00989B
Abstract: Next-generation nanozyme based biosensing: mesoporous nanocrystalline α- or γ-iron oxide?
Latent potential of current plant diagnostics for detection of sugarcane diseases
Publisher: Elsevier BV
Date: 2022
Simultaneous analysis of nitrate and nitrite in a microfluidic device with a Cu-complex-modified electrode
Publisher: Wiley
Date: 11-2006
Abstract: A CE microsystem coupled with a microchip and a copper-(3-mercaptopropyl) trimethoxysilane (Cu-MPS) complex-modified carbon paste electrode (CPE) was developed for the simultaneous analysis of nitrite and nitrate. The method is based on the electrocatalytic reduction of both analytes with the modified electrode. The Cu-MPS complex was characterized by voltammetric, XPS, and FT-IR analyses. Experimental parameters affecting the sensitivity of the modified electrode were assessed and optimized. The best separation was achieved in a 60 mm separation channel filled with a 20 mM acetate buffer of pH 5.0 containing 3.0 mM CTAB at separation field strength of -250 V/cm within 90 s. The detection potential for the simultaneous analysis of nitrite and nitrate was found to be -225 mV versus Ag/AgCl. A reproducible response (RSD of 3.2% (nitrite) and 2.8% (nitrate), n = 8) for repetitive s le injections reflected the negligible electrode fouling at the modified CPE. The interference effect was examined for other inorganic ions and biological compounds. A wide hydrodynamic range between 0.25 and 120 microM was observed for analyzing nitrite and nitrate with the sensitivities of 0.069 +/- 0.003 and 0.065 +/- 0.002 nA/microM, and the detection limits, based on S/N = 3, were found to be 0.09 +/- 0.007 and 0.08 +/- 0.009 microM, respectively. The applicability of the method to water and urine s les analyses was demonstrated.
Graphene/quantum dot bionanoconjugates as signal amplifiers in stripping voltammetric detection of EpCAM biomarkers
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.BIOS.2012.02.057
Abstract: A sensitive electrochemical immunosensor for the detection of epithelial cell adhesion molecule (EpCAM) antigen, a common marker for tumors of epithelial origin, employing bionanoconjugates as signal-transduction labels has been developed. The bionanoconjugates were fabricated by carboxylation of the two-dimensional graphene oxide nanosheets (GRs) and immobilizing streptavidin and amine-functionalized CdSe quantum dots (QDs) on carboxylated GRs via carbodiimide coupling chemistry, followed by the immunoreaction with the biotinylated secondary antibodies. Since carboxylated GRs have a higher density of active sites, it allows a large number of CdSe QDs to be immobilized onto the surface of the bionanoconjugates, and hence, enhance the sensitivity of the immunosensor. The method enabled detection limits of 100 fg/mL and 1 pg/mL (based on the S/N=3) in PBS buffer and serum s les, respectively, using anodic stripping voltammetric readout. The immunosensor showed a good selectivity, reproducibility, and long-storage stability, and may become a promising technique for the early detection of tumor biomarker in clinical/biological s les.
Electrochemical Detection of FAM134B Mutations in Oesophageal Cancer Based on DNA-Gold Affinity Interactions
Publisher: Wiley
Date: 09-02-2017
Detection of FGFR2 : FAM76A Fusion Gene in Circulating Tumor RNA Based on Catalytic Signal Amplification of Graphene Oxide-loaded Magnetic Nanoparticles
Publisher: Wiley
Date: 04-07-2018
Biological Functions and Current Advances in Isolation and Detection Strategies for Exosome Nanovesicles
Publisher: Wiley
Date: 28-12-2018
Abstract: Exosomes are nanoscale (≈30-150 nm) extracellular vesicles of endocytic origin that are shed by most types of cells and circulate in bodily fluids. Exosomes carry a specific composition of proteins, lipids, RNA, and DNA and can work as cargo to transfer this information to recipient cells. Recent studies on exosomes have shown that they play an important role in various biological processes, such as intercellular signaling, coagulation, inflammation, and cellular homeostasis. These functional roles are attributed to their ability to transfer RNA, proteins, enzymes, and lipids, thereby affecting the physiological and pathological conditions in various diseases, including cancer and neurodegenerative, infectious, and autoimmune diseases (e.g., cancer initiation, progression, and metastasis). Due to these unique characteristics, exosomes are considered promising biomarkers for the diagnosis and prognosis of various diseases via noninvasive or minimally invasive procedures. Over the last decade, a plethora of methodologies have been developed for analyzing disease-specific exosomes using optical and nonoptical tools. Here, the major biological functions, significance, and potential role of exosomes as biomarkers and therapeutics are discussed. Furthermore, an overview of the most commonly used techniques for exosome analysis, highlighting the major technical challenges and limitations of existing techniques, is presented.
An electrochemical immunosensor to minimize the nonspecific adsorption and to improve sensitivity of protein assays in human serum
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.BIOS.2012.05.014
Abstract: An electrochemical immunoassay which minimizes nonspecific protein adsorption and improves detection sensitivity of proteomic cancer biomarker is described. Our technique comprises two novel features: (i) a high density terminally functionalized poly(N-isopropyl acrylamide) 'brush' layer is grown by surface initiated reversible addition fragmentation chain transfer (RAFT) polymerization method from the electrode surface in order to minimize nonspecific adsorption of serum proteins and other biomolecules, and (ii) a signal lifying 'bionanoconjugate' comprised of graphene oxide nanosheets decorated with CdSe quantum dots and recombinant single-chain variable fragments towards MSLN, is used to 'physically' lify the anodic stripping voltammetric signal. This method enabled a detection limit of ca. 1 pg/mL MSLN (RSD=4.6%, n=4) spiked in serum s les. Because of the simple, specific and sensitive nature of this methodology, we feel that it may find potential use in serum-based protein diagnostics.
eMethylsorb: electrochemical quantification of DNA methylation at CpG resolution using DNA–gold affinity interactions
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4CC06732K
Abstract: Base dependent affinity interaction of DNA with gold has been utilised to electrochemically quantify the methylation status of bisulphite treated DNA s les.
Recent Developments of Carboxymethyl Cellulose
Publisher: MDPI AG
Date: 20-04-2021
Abstract: Carboxymethyl cellulose (CMC) is one of the most promising cellulose derivatives. Due to its characteristic surface properties, mechanical strength, tunable hydrophilicity, viscous properties, availability and abundance of raw materials, low-cost synthesis process, and likewise many contrasting aspects, it is now widely used in various advanced application fields, for ex le, food, paper, textile, and pharmaceutical industries, biomedical engineering, wastewater treatment, energy production, and storage energy production, and storage and so on. Many research articles have been reported on CMC, depending on their sources and application fields. Thus, a comprehensive and well-organized review is in great demand that can provide an up-to-date and in-depth review on CMC. Herein, this review aims to provide compact information of the synthesis to the advanced applications of this material in various fields. Finally, this article covers the insights of future CMC research that could guide researchers working in this prominent field.
miRNa signature in small extracellular vesicles and their association with platinum resistance and cancer recurrence in ovarian cancer
Publisher: Elsevier BV
Date: 08-2020
Oxi-Redox Selective Breast Cancer Treatment: An in Vitro Study of Theranostic In-Based Oxide Nanoparticles for Controlled Generation or Prevention of Oxidative Stress
Publisher: American Chemical Society (ACS)
Date: 05-01-2021
Porous nanozymes: the peroxidase-mimetic activity of mesoporous iron oxide for the colorimetric and electrochemical detection of global DNA methylation
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8TB01132J
Abstract: Peroxidase-mimetic activity of mesoporous Fe 2 O 3 nanomaterials in global DNA methylation detection using naked eye and electrochemical readout.
DNA–bare gold affinity interactions: mechanism and applications in biosensing
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5AY01479D
Abstract: Sequence-dependent non-thiolated DNA–gold affinity interaction for biosensing applications, and the underlying principles governing these interactions are comprehensively reviewed.
Highly Selective and Sensitive DNA Assay Based on Electrocatalytic Oxidation of Ferrocene Bearing Zinc(II)−Cyclen Complexes with Diethylamine
Publisher: American Chemical Society (ACS)
Date: 02-07-2010
DOI: 10.1021/JA1021365
Abstract: A highly selective and sensitive electrochemical biosensor has been developed that detects DNA hybridization by employing the electrocatalytic activity of ferrocene (Fc) bearing cyclen complexes (cyclen = 1,4,7,10-tetraazacyclododecane, Fc[Zn(cyclen)H(2)O](2)(ClO(4))(4) (R1), Fc(cyclen)(2) (R2), Fc[Zn(cyclen)H(2)O](ClO(4))(2) (R3), and Fc(cyclen) (R4)). A sandwich-type approach, which involves hybridization of a target probe hybridized with the preimmobilized thiolated capture probe attached to a gold electrode, is employed to fabricate a DNA duplex layer. Electrochemical signals are generated by voltammetric interrogation of a Fc bearing Zn-cyclen complexes that selectively and quantitatively binds to the duplex layers through strong chelation between the cyclen complexes and particular nucleobases within the DNA sequence. Chelate formation between R1 or R3 and thymine bases leads to the perturbation of base-pair (A-T) stacking in the duplex structure, which greatly diminishes the yield of DNA-mediated charge transport and displays a marked selectivity to the presence of the target DNA sequence. Coupling the redox chemistry of the surface-bound Fc bearing Zn-cyclen complex and dimethylamine provides an electrocatalytic pathway that increases sensitivity of the assay and allows the 100 fM target DNA sequence to be detected. Excellent selectivity against even single-base sequence mismatches is achieved, and the DNA sensor is stable and reusable.
Electrochemical detection of protein glycosylation using lectin and protein–gold affinity interactions
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6AN00528D
Abstract: New electrochemical method to detect glycosylation of protein using lectin and protein gold interaction.
eMethylsorb: rapid quantification of DNA methylation in cancer cells on screen-printed gold electrodes
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4AN01641F
Abstract: A simple, sensitive and inexpensive electrochemical method has been reported to detect regional DNA methylation by using differential adsorption affinity of DNA bases to gold.
Laser induced self-N-doped porous graphene as an electrochemical biosensor for femtomolar miRNA detection
Publisher: Elsevier BV
Date: 08-2020
An Interfacial Affinity Interaction-Based Method for Detecting HOTAIR lncRNA in Cancer Plasma Samples
Publisher: MDPI AG
Date: 28-04-2022
DOI: 10.3390/BIOS12050287
Abstract: Long non-coding RNA Homeobox transcript antisense intergenic RNA (HOTAIR) is recognized as a participant in different processes of normal cell development. Aberrant overexpression of HOTAIR contributes to the initiation, growth, and invasiveness of ovarian cancer. Using the affinity interaction of target HOTAIR lncRNA sequences towards a screen-printed gold electrode (SPE-Au), herein we report on a novel, rapid and simple method to detect HOTAIR sequences. HOTAIR lncRNA sequences were first extracted from ovarian cancer cell lines and patient plasma s les and were magnetically captured and purified by complimentary capture probe-functionalized magnetic beads. Isolated target HOTAIR lncRNAs were directly adsorbed onto unmodified screen-printed gold electrodes (SPE-Au) for direct quantification with [Fe(CN)6]3−/4− redox couple. Our assay achieved a linear dynamic range of 100 nM and 1 pM for detecting pre-clinical model HOTAIR lncRNA s les (%RSD ≤ 5%, for n = 3) and was highly specific, showing clear distinction between HOTAIR lncRNA targets and non-specific miR-891 and miR-486 (100 nM) (%RSD ≤ 5%, for n = 3). The method was tested using ovarian cancer-specific cell lines (SKOV3 and OVCAR3) and mesothelial cell line (MeT-5A)-derived lncRNAs. The analytical performance of our method was validated using RT-qPCR. Finally, the method was tested using clinical s les from ovarian cancer patients and the resulting electrochemical responses show a clear distinction between the ovarian carcinoma and benign s les.
Nonadditivity of Faradaic Currents and Modification of Capacitance Currents in the Voltammetry of Mixtures of Ferrocene and the Cobaltocenium Cation in Protic and Aprotic Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 26-05-2009
DOI: 10.1021/JA8092295
Abstract: Unexpected nonadditivity of currents encountered in the electrochemistry of mixtures of ferrocene (Fc) and cobaltocenium cation (Cc(+)) as the PF(6)(-) salt has been investigated by direct current (dc) and Fourier-transformed alternating current (ac) cyclic voltammetry in two aprotic (1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate) and three protic (triethylammonium formate, bis(2-hydroxyethyl)ammonium acetate, and triethylammonium acetate) ionic liquids (ILs). The voltammetry of the in idual Fc(0/+) and Cc(+/0) couples always exhibits near-Nernstian behavior at glassy carbon and gold electrodes. As expected for an ideal process, the reversible formal potentials and diffusion coefficients at 23 +/- 1 degrees C in each IL determined from measurement on in idual Fc and Cc(+) solutions were found to be independent of electrode material, concentration, and technique used for the measurement. However, when Fc and Cc(+) were simultaneously present, the dc and ac peak currents per unit concentration for the Fc(0/+) and Cc(+/0) processes were found to be significantly enhanced in both aprotic and protic ILs. Thus, the apparent diffusion coefficient values calculated for Fc and Cc(+) were respectively found to be about 25 and 35% larger than those determined in idually in the aprotic ILs. A similar change in the Fc(0/+) mass transport characteristics was observed upon addition of tetrabutylammonium hexafluorophosphate (Bu(4)NPF(6)), and the double layer capacitance also varied in distinctly different ways when Fc and Cc(+) were present in idually or in mixtures. Importantly, the nonadditivity of Faradaic current is not associated with a change in viscosity or from electron exchange as found when some solutes are added to ILs. The observation that the (1)H NMR T(1) relaxation times for the proton resonance in Cc(+) also are modified in mixed systems implies that specific interaction with aggregates of the constituent IL ionic species giving rise to subtle structural changes plays an important role in modifying the mass transport, double layer characteristics, and dynamics when solutes of interest in this study are added to ILs. Analogous voltammetric changes were not observed in studies in organic solvent media containing 0.1 M added supporting electrolyte. Implications of the nonadditivity of Faradaic and capacitance terms in ILs are considered.
Superparamagnetic Gadolinium Ferrite Nanoparticles with Controllable Curie Temperature – Cancer Theranostics for MR‐Imaging‐Guided Magneto‐Chemotherapy
Publisher: Wiley
Date: 30-08-2016
An impedimetric immunosensor for the label-free detection of bisphenol A
Publisher: Elsevier BV
Date: 15-05-2007
DOI: 10.1016/J.BIOS.2006.09.010
Abstract: Label-free detection of bisphenol A based on the impedance measurement was achieved with an impedimetric immunosensor. The immunosensor was fabricated by the covalent bond formation between a polyclonal antibody and a carboxylic acid group functionalized onto a nano-particle comprised conducting polymer. By using a commercial reagent 4,4-bis(4-hydroxyphenyl) valeric acid (BHPVA), which has an analogous structure of BPA, we have prepared the antigen through the conjugation of BHPVA with bovine serum albumin (BSA) and then produced a specific polyclonal antibody. The immobilization of antibody and the interaction between antibody and antigen were studied using quartz crystal microbalance (QCM) and electrochemical impedance spectroscopic (EIS) techniques. The impedance and mass changes due to the specific immuno-interaction at the sensor surface were utilized to detect antigen and bisphenol A (BPA). The immunosensor showed specific recognition of BPA with less interference than 4.5% from other common phenolic compounds. Under an optimized condition, the linear dynamic range of BPA detection was between 1 and 100 ng/ml. The detection limit of bisphenol A was determined to be 0.3+/-0.07 ng/ml. The proposed immunosensor was applied to a human serum s le and the BPA concentration was determined by the standard addition method.
Self-sacrificial templated synthesis of a three-dimensional hierarchical macroporous honeycomb-like ZnO/ZnCo2O4 hybrid for carbon monoxide sensing
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8TA11380G
Abstract: A 3D macroporous honeycomb-like ZnO/ZnCo 2 O 4 hybrid for CO sensing is reported.
Naked-eye and electrochemical detection of isothermally amplified HOTAIR long non-coding RNA
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7AN02109G
Abstract: A naked-eye, colorimetric and electrochemical detection of HOTAIR long non-coding RNA has been demonstrated.
Advanced liquid biopsy technologies for circulating biomarker detection
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TB01490J
Abstract: In this review, we have summarised the biogenesis, biological significance, isolation and detection technologies of four widely known circulating biomarkers namely circulating tumour cells, circulating tumor specific DNA, microRNA, and exosomes.
DNA methylation detection: recent developments in bisulfite free electrochemical and optical approaches
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8AN01348A
Abstract: The recent development of optical and electrochemical biosensors for bisulfite treatment free DNA methylation detection methods have been reviewed. The major challenges associated with the bisulfite treatment in DNA methylation detection and their potential solutions are also discussed.
Synthesis of nanoporous poly-melamine-formaldehyde (PMF) based on Schiff base chemistry as a highly efficient adsorbent
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8AN01623B
Abstract: This study proposes the construction of nanoporous poly-melamine-formaldehyde through the Schiff base condensation of paraformaldehyde and melamine.
Methylsorb: A Simple Method for Quantifying DNA Methylation Using DNA–Gold Affinity Interactions
Publisher: American Chemical Society (ACS)
Date: 29-09-2014
DOI: 10.1021/AC502214Z
Abstract: The analysis of DNA methylation is becoming increasingly important both in the clinic and also as a research tool to unravel key epigenetic molecular mechanisms in biology. Current methodologies for the quantification of regional DNA methylation (i.e., the average methylation over a region of DNA in the genome) are largely affected by comprehensive DNA sequencing methodologies which tend to be expensive, tedious, and time-consuming for many applications. Herein, we report an alternative DNA methylation detection method referred to as "Methylsorb", which is based on the inherent affinity of DNA bases to the gold surface (i.e., the trend of the affinity interactions is adenine > cytosine ≥ guanine > thymine).1 Since the degree of gold-DNA affinity interaction is highly sequence dependent, it provides a new capability to detect DNA methylation by simply monitoring the relative adsorption of bisulfite treated DNA sequences onto a gold chip. Because the selective physical adsorption of DNA fragments to gold enable a direct read-out of regional DNA methylation, the current requirement for DNA sequencing is obviated. To demonstrate the utility of this method, we present data on the regional methylation status of two CpG clusters located in the EN1 and MIR200B genes in MCF7 and MDA-MB-231 cells. The methylation status of these regions was obtained from the change in relative mass on gold surface with respect to relative adsorption of an unmethylated DNA source and this was detected using surface plasmon resonance (SPR) in a label-free and real-time manner. We anticipate that the simplicity of this method, combined with the high level of accuracy for identifying the methylation status of cytosines in DNA, could find broad application in biology and diagnostics.
Gold-loaded nanoporous ferric oxide nanocubes for electrocatalytic detection of microRNA at attomolar level
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.BIOS.2017.09.027
Abstract: A crucial issue in microRNA (miRNA) detection is the lack of sensitive method capable of detecting the low levels of miRNA in RNA s les. Herein, we present a sensitive and specific method for the electrocatalytic detection of miR-107 using gold-loaded nanoporous superparamagnetic iron oxide nanocubes (Au-NPFe
An amplification-free electrochemical detection of exosomal miRNA-21 in serum samples
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7AN01843F
Abstract: A sensitive and lification-free assay for the electrochemical detection of exosomal miRNAs in complex biological s les.
Gold-Loaded Nanoporous Ferric Oxide Nanocubes with Peroxidase-Mimicking Activity for Electrocatalytic and Colorimetric Detection of Autoantibody
Publisher: American Chemical Society (ACS)
Date: 26-09-2017
DOI: 10.1021/ACS.ANALCHEM.7B02880
Abstract: The enzyme-mimicking activity of iron oxide based nanostructures has provided a significant advantage in developing advanced molecular sensors for biomedical and environmental applications. Herein, we introduce the horseradish peroxidase (HRP)-like activity of gold-loaded nanoporous ferric oxide nanocubes (Au-NPFe
CRISPR/Cas-Based Diagnostics in Agricultural Applications
Publisher: American Chemical Society (ACS)
Date: 28-07-2023
Microdevices for detecting locus-specific DNA methylation at CpG resolution
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.BIOS.2014.01.029
Abstract: Simple, rapid, and inexpensive strategies for detecting DNA methylation could facilitate routine patient diagnostics. Herein, we describe a microdevice based electrochemical assay for the detection of locus-specific DNA methylation at single CpG dinucleotide resolution after bisulfite conversion of a target DNA sequence. This is achieved by using the ligase chain reaction (LCR) to recognize and lify a C to T base change at a CpG site and measuring the change electrochemically (eLCR). Unlike other electrochemical detection methods for DNA methylation, methylation specific (MS)-eLCR can potentially interrogate any CpG of interest in the genome. MS-eLCR also distinguishes itself from other electrochemical LCR detection schemes by integrating a peroxidase-mimicking DNAzyme sequence into the LCR lification probes design which in turn, serves as a redox moiety when bound with a hemin cofactor. Following hybridization to surface-bound capture probes, the DNAzyme-linked LCR products induce electrocatalytic responses that are proportional to the methylation levels of the gene locus in the presence of hydrogen peroxide. The performance of the assay was evaluated by simultaneously detecting C to T changes at a locus associated with cancer metastasis in breast cancer cell lines and serum-derived s les. MS-eLCR required as little as 0.04 pM of starting material and was sensitive to 10-15% methylation change with good reproducibility (RSD=7.9%, n=3). Most importantly, the accuracy of the method in quantifying locus-specific methylation was comparable to both fluorescence-based and Next Generation Sequencing approaches. We thus believe that the proposed assay could potentially be a low cost alternative to current technologies for DNA methylation detection of specific CpG sites.
Hydrazine-Catalyzed Ultrasensitive Detection of DNA and Proteins
Publisher: American Chemical Society (ACS)
Date: 08-08-2007
DOI: 10.1021/AC0710127
Abstract: A sensitive electrochemical assay of DNA and proteins employing electrocatalytic reduction of hydrogen peroxide by labeled hydrazine on the probe immobilized surfaces was developed. The method utilizes a conducting polymer, poly-5, 2':5', 2''-terthiophene-3'-carboxylic acid (pTTCA), covalently linked to the dendrimer (DEN) and hydrazine. The detection signal was lified by the pTTCA/DEN assembly loaded with Au nanoparticles (particle size, approximately 3.5 nm) onto which huge target DNA- or proteins-linked hydrazine labels (avidin-hydrazine) were adsorbed. The linear dynamic ranges for the electrocatalytic detection of DNA and proteins, extending from 1.0 fM to 10 microM and 10 fg/mL to 10 ng/mL, were observed, along with the detection limits of 450 aM (2700 DNA molecules in a 10-microL s le) and 4.0 fg/mL, respectively. The method eliminates the use of enzymes for DNA and protein detection and opens a way for DNA-free detection of proteins. The simplicity, good reproducibility (RSD, <4.3% for n = 10), and low detection limit of the method offer a good promise for practical DNA and protein analyses.
Superparamagnetic nanoarchitectures for disease-specific biomarker detection
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CS00174C
Abstract: Synthesis, bio-functionalization, and multifunctional activities of superparamagnetic-nanostructures have been extensively reviewed with a particular emphasis on their uses in a range of disease-specific biomarker detection and associated challenges.
Quantum dot-based sensitive detection of disease specific exosome in serum
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7AN00672A
Abstract: We report a stripping voltammetric immunoassay for the electrochemical detection of disease specific exosomes using quantum dots as electrochemical signal lifiers.
Potentials of mycosynthesized nanomaterials for efficient remediation of environmental contaminants
Publisher: Elsevier
Date: 2022
Robust Free-Standing Nano-Thin SiC Membranes Enable Direct Photolithography for MEMS Sensing Applications
Publisher: Wiley
Date: 15-12-2018
Potential Avenues for Exosomal Isolation and Detection Methods to Enhance Small-Cell Lung Cancer Analysis
Publisher: American Chemical Society (ACS)
Date: 14-02-2023
Fabrication of disposable sensors for biomolecule detection using hydrazine electrocatalyst
Publisher: Elsevier BV
Date: 08-2008
Abstract: We have developed electrochemical DNA and protein sensors on screen-printed electrodes based on the catalytic activity of hydrazine. The sensors use carboxylic acid-functionalized conductive polymer, poly-5,2',5',2''-terthiophene-3'-carboxylic acid (polyTTCA) to make firm immobilization of dendrimer (DEN) through the covalent bond formation between the carboxylic acid groups of polymer and amine groups of dendrimer. The gold nanoparticles (AuNPs) were adsorbed on the remaining amine groups of dendrimer. The thiolated DNA probe or primary antibody was subsequently immobilized on the AuNP-covered dendrimer surfaces. Avidin-labeled hydrazine (Av-Hyd) was then immobilized on the sensor surfaces through the avidin-biotin interaction between the Av-Hyd unit and the biotinylated DNA or secondary antibody. The electrocatalytic reduction current of H(2)O(2) was measured by differential pulse voltammetry. The detection signal was lified by the polyTTCA/DEN assembly loaded with AuNPs (approximately 3.5 nm) onto which target analyte-linked Av-Hyd was adsorbed. Linear dynamic ranges for the electrocatalytic detection of DNA and human immunoglobulin G (IgG) extending from 50 fM to 7.5 nM and from 40 fg/ml to 2.5 ng/ml, respectively, were observed along with detection limits of approximately 30 fM and 25 fg/ml, respectively. The low detection limit of the disposable sensors offers good promise for practical DNA and protein detection.
Tunable “Nano-Shearing”: A Physical Mechanism to Displace Nonspecific Cell Adhesion During Rare Cell Detection
Publisher: American Chemical Society (ACS)
Date: 04-02-2014
DOI: 10.1021/AC4032516
Abstract: We report a tunable alternating current electro-hydrodynamic (ac-EHD) force which drives lateral fluid motion within a few nanometers of an electrode surface. Because the magnitude of this fluid shear force can be tuned externally (e.g., via the application of an ac electric field), it provides a new capability to physically displace weakly (nonspecifically) bound cellular analytes. To demonstrate the utility of the tunable nanoshearing phenomenon, we present data on purpose-built microfluidic devices that employ ac-EHD force to remove nonspecific adsorption of molecular and cellular species. Here, we show that an ac-EHD device containing asymmetric planar and microtip electrode pairs resulted in a 4-fold reduction in nonspecific adsorption of blood cells and also captured breast cancer cells in blood, with high efficiency (approximately 87%) and specificity. We therefore feel that this new capability of externally tuning and manipulating fluid flow could have wide applications as an innovative approach to enhance the specific capture of rare cells such as cancer cells in blood.
A Multiplexed Device Based on Tunable Nanoshearing for Specific Detection of Multiple Protein Biomarkers in Serum
Publisher: Springer Science and Business Media LLC
Date: 15-05-2015
DOI: 10.1038/SREP09756
Abstract: Microfluidic flow based multiplexed devices have gained significant promise in detecting biomarkers in complex biological s les. However, to fully exploit their use in bioanalysis, issues such as (i) low sensitivity and (ii) high levels of nonspecific adsorption of non-target species have to be overcome. Herein, we describe a new multiplexed device for the sensitive detection of multiple protein biomarkers in serum by using an alternating current (ac) electrohydrodynamics (ac-EHD) induced surface shear forces based phenomenon referred to as nanoshearing . The tunable nature (via manipulation of ac field) of these nanoshearing forces can alter the capture performance of the device ( e.g. , improved fluid transport enhances number of sensor-target collisions). This can also selectively displace weakly (nonspecifically) bound molecules from the electrode surface ( i.e. , fluid shear forces can be tuned to shear away nonspecific species present in biological s les). Using this approach, we achieved sensitive (100 fg mL −1 ) naked eye detection of multiple protein targets spiked in human serum and a 1000-fold enhancement in comparison to hydrodynamic flow based devices for biomarker detection. We believe that this approach could potentially represent a clinical diagnostic tool that can be integrated into resource-limited settings for sensitive detection of target biomarkers using naked eye.
Nanotechnology and its medical applications: revisiting public policies from a regulatory perspective in Australia
Publisher: Walter de Gruyter GmbH
Date: 27-06-2017
Abstract: Nanobiotechnology is an immensely potential invention, which is expected to bring about revolutionary changes in many aspects of essential human needs including medical treatments and foods. Although the technology has passed through its embryonic stage, its medical applications in preparing and delivering drugs to target cells of human bodies to cure incurable diseases are still under scientific scrutiny. A 2007 study suggests that Australia needs to have a review of its regulatory framework for nanotechnology by 2017. This article examines the current regulation of nanotechnology and its medical applications in Australia, and observes that it would be premature to impose any stringent regulation at this stage on medical experimentations. We are of the view that an excessively precautionary policy may hinder further research, which is critical to discovering the benefit and harm with certainty. Hence, in the greater interest of the facilitation of research and affirmation of benefits of this technology, we recommend that adopting a hybrid regulatory method composed of self-regulation and accommodating government regulation would be an appropriate policy approach to the regulation of nanobiotechnology. We also accept the need for a set of internationally harmonized policy principles to guide our actions in relation to this technology.
Enhancing Protein Capture Using a Combination of Nanoyeast Single-Chain Fragment Affinity Reagents and Alternating Current Electrohydrodynamic Forces
Publisher: American Chemical Society (ACS)
Date: 18-11-2015
DOI: 10.1021/ACS.ANALCHEM.5B02490
Abstract: New high-performance detection technologies and more robust protein capture agents can be combined to both rapidly and specifically capture and detect protein biomarkers associated with disease in complex biological s les. Here we demonstrate the use of recently developed recombinant affinity reagents, namely nanoyeast-scFv, in combination with alternating current electrohydrodynamic (ac-EHD)-induced shear forces, to enhance capture performance during protein biomarker analysis. The use of ac-EHD significantly improves fluid transport across the capture domain, resulting in enhanced sensor-target interaction and simultaneous displacement of nonspecific molecules from the electrode surface. We demonstrate this simple proof-of-concept approach for the capture and detection of Entamoeba histolytica antigens from disinfected stool, within a span of 5 min using an ac-EHD microfluidic device. Under an ac-EHD field, antigens were captured on a nanoyeast-scFv immobilized device and subsequently detected using a quantum dot conjugated antibody. This immunosensor specifically detected antigen in disinfected stool with low background noise at concentrations down to 58.8 fM with an interassay reproducibility (%RSD of n = 3) < 17.2%, and in buffer down to 5.88 fM with an interassay reproducibility (% RSD, n = 3) of 8.4%. Furthermore, antigen detection using this immunosensor was 10 times more sensitive than previously obtained with the same nanoyeast-scFv reagents in a microfluidic device employing surface-enhanced Raman scattering (SERS) detection in buffer and at least 200 times more sensitive than methods using screen printed gold electrodes in disinfected stool. We predict this rapid and sensitive approach using these stable affinity reagents may offer a new methodology to detect protein disease biomarkers from biological matrices.
Fabrication and characterization of gold nanohole electrode arrays
Publisher: Elsevier BV
Date: 10-2012
Electrochemical biosensing strategies for DNA methylation analysis
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.BIOS.2017.02.026
Abstract: DNA methylation is one of the key epigenetic modifications of DNA that results from the enzymatic addition of a methyl group at the fifth carbon of the cytosine base. It plays a crucial role in cellular development, genomic stability and gene expression. Aberrant DNA methylation is responsible for the pathogenesis of many diseases including cancers. Over the past several decades, many methodologies have been developed to detect DNA methylation. These methodologies range from classical molecular biology and optical approaches, such as bisulfite sequencing, microarrays, quantitative real-time PCR, colorimetry, Raman spectroscopy to the more recent electrochemical approaches. Among these, electrochemical approaches offer sensitive, simple, specific, rapid, and cost-effective analysis of DNA methylation. Additionally, electrochemical methods are highly amenable to miniaturization and possess the potential to be multiplexed. In recent years, several reviews have provided information on the detection strategies of DNA methylation. However, to date, there is no comprehensive evaluation of electrochemical DNA methylation detection strategies. Herein, we address the recent developments of electrochemical DNA methylation detection approaches. Furthermore, we highlight the major technical and biological challenges involved in these strategies and provide suggestions for the future direction of this important field.
Raman spectroscopy and microscopy in biomedical nanotechnology
Publisher: IOP Publishing
Date: 07-2023
Sustainable Antibiotic-Free Broiler Meat Production: Current Trends, Challenges, and Possibilities in a Developing Country Perspective
Publisher: MDPI AG
Date: 23-11-2020
Abstract: Antibiotic-free broiler meat production is becoming increasingly popular worldwide due to consumer perception that it is superior to conventional broiler meat. Globally, broiler farming impacts the income generation of low-income households, helping to alleviate poverty and secure food in the countryside and in semi-municipal societies. For decades, antibiotics have been utilized in the poultry industry to prevent and treat diseases and promote growth. This practice contributes to the development of drug-resistant bacteria in livestock, including poultry, and humans through the food chain, posing a global public health threat. Additionally, consumer demand for antibiotic-free broiler meat is increasing. However, there are many challenges that need to be overcome by adopting suitable strategies to produce antibiotic-free broiler meat with regards to food safety and chicken welfare issues. Herein, we focus on the importance and current scenario of antibiotic use, prospects, and challenges in the production of sustainable antibiotic-free broiler meat, emphasizing broiler farming in the context of Bangladesh. Moreover, we also discuss the need for and challenges of antibiotic alternatives and provide a future outlook for antibiotic-free broiler meat production.
Correction: Gold-loaded nanoporous iron oxide nanocubes: a novel dispersible capture agent for tumor-associated autoantibody analysis in serum
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR90194A
Abstract: Correction for ‘Gold-loaded nanoporous iron oxide nanocubes: a novel dispersible capture agent for tumor-associated autoantibody analysis in serum’ by Sharda Yadav et al. , Nanoscale , 2017, 9 , 8805–8814.
Separation of distinct exosome subpopulations: isolation and characterization approaches and their associated challenges
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1AN00024A
Abstract: Currently, there exists a multitude of different exosome isolation and characterization approaches based on biophysical and/or biochemical characteristics. Herein we review various technologies for separation of distinct exosome subpopulations.
ACE inhibitor induced intestinal angioedema
Publisher: Wiley
Date: 23-02-2022
DOI: 10.1111/ANS.17575
DNA‐Templated Copper Nanoprobes: Overview, Feature, Application, and Current Development in Detection Technologies
Publisher: Wiley
Date: 12-07-2019
Abstract: Metal nanoprobes have recently attracted board research interestinr their application in establishing sensing systems due to their unique optical, electrical, physical, and chemical properties. In comparison to gold and silver nanoprobes, analytical platform based on copper nanoprobes (Cu-NPs) is still in the early stages of development. In this review, we focus on single-stranded, and double-stranded DNA capped Cu-NPs sensing systems which have been designed for various analytes, including metal ions, anions, small molecules, biomolecules (DNA, RNA, and protein, etc.). In addition, the application of Cu-NPs in biological labeling or bio-imaging platforms has also been introduced and summarized.
Nonadditivity of Faradaic Currents and Modification of Double Layer Capacitance in the Voltammetry of Mixtures of Ferrocene and Ferrocenium Salts in Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 28-01-2010
DOI: 10.1021/AC9020159
Abstract: Electrochemical studies on the Fc + e(-) Fc(+) (Fc = ferrocene) process have been undertaken via the oxidation of Fc and reduction of Fc(+) as the hexafluorophosphate (PF(6)(-)) or tetrafluoroborate (BF(4)(-)) salts and their mixtures in three ionic liquids (ILs) (1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide, 1-butyl-3-methylimidazolium tetrafluoroborate, and 1-butyl-3-methylimidazolium hexafluorophosphate). Data obtained at macro- and microdisk electrodes using conventional dc and Fourier-transformed large- litude ac (FT-ac) voltammetry reveal that diffusion coefficients for Fc and Fc(+) differ significantly and are a function of the Fc and Fc(+) concentration, in contrast to findings in molecular solvents with 0.1 M added supporting electrolyte media. Thus, the faradaic currents associated with the oxidation of Fc (Fc(0/+)) and reduction of FcPF(6) or FcBF(4) (Fc(+/0)) when both Fc and Fc(+) are simultaneously present in the ILs differ from values obtained when in idual Fc and Fc(+) solutions are used. The voltammetry for both the Fc(0/+) and Fc(+/0) processes exhibited near-Nernstian behavior at a glassy carbon macrodisk electrode and a platinum microdisk electrode, when each process was studied in idually in the ILs. As expected, the reversible formal potentials (E(o)') and diffusion coefficients (D) at 23 +/- 1 degrees C were independent of the electrode material and concentration. However, when Fc and FcPF(6) or FcBF(4) were both present, alterations to the mass transport process occurred and apparent D values calculated for Fc and Fc(+) were found to be about 25-39% and 32-42% larger, respectively, than those determined from in idual solutions. The apparent value of the double layer capacitance determined by FT-ac voltammetry from in idual and mixed Fc and Fc(+) conditions at the GC electrode was also a function of concentration. Double layer capacitance values increased significantly with the concentration of Fc and FcPF(6) or FcBF(4) when species were studied in idually or simultaneously, but had a larger magnitude under conditions where both species were present. Variation in the structure of the ILs and hence mobilities of the ionic species, when Fc and FcPF(6) or FcBF(4) are simultaneously present, is considered to be the origin of the nonadditivity of the faradaic currents and variation in capacitance.
Detection of regional DNA methylation using DNA-graphene affinity interactions
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.BIOS.2016.09.016
Abstract: We report a new method for the detection of regional DNA methylation using base-dependent affinity interaction (i.e., adsorption) of DNA with graphene. Due to the strongest adsorption affinity of guanine bases towards graphene, bisulfite-treated guanine-enriched methylated DNA leads to a larger amount of the adsorbed DNA on the graphene-modified electrodes in comparison to the adenine-enriched unmethylated DNA. The level of the methylation is quantified by monitoring the differential pulse voltammetric current as a function of the adsorbed DNA. The assay is sensitive to distinguish methylated and unmethylated DNA sequences at single CpG resolution by differentiating changes in DNA methylation as low as 5%. Furthermore, this method has been used to detect methylation levels in a collection of DNA s les taken from oesophageal cancer tissues.
Placental Exosomes as Biomarkers for Maternal Diseases: Current Advances in Isolation, Characterization, and Detection
Publisher: American Chemical Society (ACS)
Date: 14-07-2023
Poly(A) Extensions of miRNAs for Amplification-Free Electrochemical Detection on Screen-Printed Gold Electrodes
Publisher: American Chemical Society (ACS)
Date: 29-01-2016
DOI: 10.1021/ACS.ANALCHEM.5B04795
Abstract: Current lification-based microRNA (miRNA) detection approaches are limited by the small sizes of miRNAs as well as lification bias/artifacts. Herein, we report on an lification-free miRNA assay based on elevated affinity interaction between polyadenylated miRNA and bare gold electrode. The poly(A) extension on the 3' ends of magnetically isolated miRNA targets facilitated high adsorption efficiency onto gold electrode surfaces for electrochemical detection without any cumbersome electrode surface functionalization procedures. The assay showed excellent detection sensitivity (10 fM) and specificity and was demonstrated for quantitative miR-107 detection in human cancer cell lines and clinical urine s les. We believe our assay could be useful as an lification-free alternative for miRNA detection.
Gold-loaded nanoporous iron oxide nanocubes: A novel dispersible capture agent for tumor-associated autoantibody analysis in serum
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR03006A
Abstract: An electrochemical and colorimetric method for detecting autoantibodies using gold-loaded nanoporous Fe 2 O 3 nanocubes as capture agents is reported for the first time.
A bisulfite treatment and PCR-free global DNA methylation detection method using electrochemical enzymatic signal engagement
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.BIOS.2018.10.020
Abstract: In this paper we report on a bisulfite treatment and PCR lification-free method for sensitive and selective quantifying of global DNA methylation. Our method utilizes a three-step strategy that involves (i) initial isolation and denaturation of global DNA using the standard isolation protocol and direct adsorption onto a bare gold electrode via gold-DNA affinity interaction, (ii) selective interrogation of methylation sites in adsorbed DNA via methylation-specific 5mC antibody, and (iii) subsequent signal enhancement using an electrochemical-enzymatic redox cycling reaction. In the redox cycling reaction, glucose oxidase (GO
Isolation and detection of exosomes using Fe2O3 nanoparticles
Publisher: American Chemical Society (ACS)
Date: 19-01-2021
Naked eye evaluation and quantitative detection of the sugarcane leaf scald pathogen,
Publisher: CSIRO Publishing
Date: 26-05-2021
DOI: 10.1071/CP20416
Abstract: Sugarcane leaf scald caused by the bacterium Xanthomonas albilineans is a major disease of sugarcane worldwide. Whereas erratic symptoms make phenotypic detection challenging, molecular methods require expensive instruments and labour, and longer s le-to-answer times. We report a novel method for detection of X. albilineans DNA in sugarcane xylem sap. The method involves (i) boiling lysis-based DNA extraction from sugarcane sap (ii) magnetic purification of target sequences directly from the lysate through use of magnetic bead-bound capture probes and (iii) DNA sandwich hybridisation platform for HRP/TMB/H2O2 reaction-based naked eye visualisation and electrochemical detection of the target. The method is sensitive (limit of detection 100 fM) and reproducible (relative standard deviation %) with linear dynamic range 100 fM–1 nM (R2 = 0.99). The method was tested on a range of sugarcane cultivars of known resistance ratings (susceptible, intermediate resistant, and resistant) for leaf scald disease from an inoculated field trial. Detection levels agreed with the resistance rating of cultivars tested. In addition, qPCR results strongly correlated with our assay (r = 0.91–0.99, P 0.01) and cultivar resistance rating. We believe that our assay could be useful for rapid screening as well as sensitive quantification of target pathogen DNA in infected sugarcane plants.
Microchip capillary electrophoresis with a cellulose-DNA-modified screen-printed electrode for the analysis of neurotransmitters
Publisher: Wiley
Date: 08-2005
Abstract: A microfluidic chip based on capillary electrophoresis coupled with a cellulose-single-stranded DNA (cellulose-ssDNA) modified electrode was used for the simultaneous analysis of dopamine (DA), norepinephrine (NE), 3,4-dihydroxy-L-phenylalanine (L-DOPA), 3,4-dihydroxyphenylacetic acid (DOPAC), and ascorbic acid (AA). The modification of the electrode improved the electrophoretic analysis performance by lowering the detection potential and enhancing the signal-to-noise characteristic without surface poisoning of the electrode. The sensitivity of the modified electrode was about 12 times higher than those of the bare ones. The test compounds were separated using a 62 mm long separation channel at the separation field strength of +200 V/cm within 220 s in a 10 mM phosphate buffer (pH 7.4). The most favorable potential for the erometric detection was 0.7 V (vs. Ag/AgCl). A reproducible response (relative standard deviation of 1.3, 1.3, 2.1, 3.1, 3.4% for DA, NE, L-DOPA, DOPAC, and AA, respectively, for n = 9) for repetitive s le injections reflected the negligible electrode fouling at the cellulose-ssDNA modified electrode. Square-wave voltammetric analyses reflected the sensitivities of the modified electrode for DA, NE, L-DOPA, DOPAC, and AA which were 1.78, 0.82, 0.69, 2.45, and 1.23 nC/microM with detection limits of 0.032, 0.93, 1.13, 0.31, and 0.62 microM, respectively. The applicability of this microsystem to real s le analysis was demonstrated.
Nanoarchitecture Frameworks for Electrochemical miRNA Detection
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.TIBS.2018.11.012
Abstract: With revolutionary advances in next-generation sequencing, the human transcriptome has been comprehensively interrogated. These discoveries have highlighted the emerging functional and regulatory roles of a large fraction of RNAs suggesting the potential they might hold as stable and minimally invasive disease biomarkers. Although a plethora of molecular-biology- and biosensor-based RNA-detection strategies have been developed, clinical application of most of these is yet to be realized. Multifunctional nanomaterials coupled with sensitive and robust electrochemical readouts may prove useful in these applications. Here, we summarize the major contributions of engineered nanomaterials-based electrochemical biosensing strategies for the analysis of miRNAs. With special emphasis on nanostructure-based detection, this review also chronicles the needs and challenges of miRNA detection and provides a future perspective on the presented strategies.
Self‐Assembly of Polymeric Micelles Made of Asymmetric Polystyrene‐ b ‐Polyacrylic Acid‐ b ‐Polyethylene Oxide for the Synthesis of Mesopo
Publisher: Wiley
Date: 10-03-2017
Recent advances in liquid biopsy technologies for cancer biomarker detection
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2SD00010E
Abstract: The current and emerging liquid biopsy methods for analysing three major circulating biomarkers namely ctDNA, CTCs and exosomes as well as biological and technical challenges associated with these methods have been reviewed.
Magnetofluidic micromixer based on a complex rotating magnetic field
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7RA08073E
Abstract: We report a magnetically actuated micromixer for mixing non-magnetic microparticles in a microfluidic system.
Current advances in detecting genetic and epigenetic biomarkers of colorectal cancer
Publisher: Elsevier BV
Date: 11-2023
Cyano-Bridged Trimetallic Coordination Polymer Nanoparticles and Their Thermal Decomposition into Nanoporous Spinel Ferromagnetic Oxides
Publisher: Wiley
Date: 04-09-2016
Abstract: The synthesis of a novel family of cyano-bridged trimetallic coordination polymers (CPs) with various compositions and shapes has been reported by changing the compositional ratios of Fe, Co, and Ni species in the reaction system. In order to efficiently control the nucleation rate and the crystal growth, trisodium citrate dihydrate plays an important role as a chelating agent. After the obtained cyano-bridged trimetallic CPs undergo thermal treatment in air at three different temperatures (250, 350, and 450 °C), nanoporous spinel metal oxides are successfully obtained. Interestingly, the obtained nanoporous metal oxides are composed of small crstalline grains, and the grains are oriented in the same direction, realizing pseudo-single crystals with nanopores. The resultant nanoporous spinel oxides feature interesting magnetic properties. Cyano-bridged multimetallic CPs with various sizes and shapes can provide a pathway toward functional nanoporous metal oxides that are not attainable from simple cyano-bridged CPs containing single metal ions.
Real time and label free profiling of clinically relevant exosomes
Publisher: Springer Science and Business Media LLC
Date: 28-07-2016
DOI: 10.1038/SREP30460
Abstract: Tumor-derived exosomes possess significant clinical relevance due to their unique composition of genetic and protein material that is representative of the parent tumor. Specific isolation as well as identification of proportions of these clinically relevant exosomes (CREs) from biological s les could help to better understand their clinical significance as cancer biomarkers. Herein, we present a simple approach for quantification of the proportion of CREs within the bulk exosome population isolated from patient serum. This proportion of CREs can potentially inform on the disease stage and enable non-invasive monitoring of inter-in idual variations in tumor-receptor expression levels. Our approach utilises a Surface Plasmon Resonance (SPR) platform to quantify the proportion of CREs in a two-step strategy that involves ( i ) initial isolation of bulk exosome population using tetraspanin biomarkers (i.e., CD9, CD63), and ( ii ) subsequent detection of CREs within the captured bulk exosomes using tumor-specific markers (e.g., human epidermal growth factor receptor 2 (HER2)). We demonstrate the isolation of bulk exosome population and detection of as low as 10% HER2(+) exosomes from s les containing designated proportions of HER2(+) BT474 and HER2(−) MDA-MB-231 cell derived exosomes. We also demonstrate the successful isolation of exosomes from a small cohort of breast cancer patient s les and identified that approximately 14–35% of their bulk population express HER2.
Ratoon Stunting Disease (RSD) of Sugarcane: A Review Emphasizing Detection Strategies and Challenges
Publisher: Scientific Societies
Date: 02-08-2023
DOI: 10.1094/PHYTO-05-23-0181-RVW
Abstract: Sugarcane (Saccharum hybrid) is an important cash crop grown in tropical and subtropical countries. Ratoon stunting disease (RSD), caused by a xylem-inhabiting bacterium Leifsonia xyli subsp. xyli (Lxx), is one of the most economically significant globally. RSD results in severe yield losses due to its highly contagious nature, lacks of visually identifiable symptoms, make it harder to devise an effective management strategy. Efficacy of the current management practices is hindered by implementation difficulties due to the lack of resources, high cost, and difficulties in monitoring. Rapid detection of the causal pathogen in vegetative planting material is crucial for sugarcane growers to manage this disease. Several microscopic, serological, and molecular-based methods have been developed and used for detecting the RSD pathogen. Although these methods have been used across the sugarcane industry worldwide to diagnose Lxx, some lack reliability or specificity, are expensive, and time-consuming to apply, and most of all, are not suitable for on-farm diagnosis. In recent decades, there has been significant progress in the development of integrated isothermal lification-based microdevices for accurate human and plant pathogen detection. There is a significant opportunity to develop a novel diagnostic method that integrates nano-biosensing with isothermal lification within a microdevice format for accurate Lxx detection. In this review, we summarize (i) the historical background and current knowledge of sugarcane ratoon stunting disease, including some aspects related to transmission, pathosystem, and management practices and (ii) the drawbacks of current diagnostic methods and potential for application of advanced diagnostics to improve disease management.
Advances in nanotechnology-based strategies for the point-of-care detection of pathogenic fungi
Publisher: Elsevier
Date: 2023
Long-Lived, Transferred Crystalline Silicon Carbide Nanomembranes for Implantable Flexible Electronics
Publisher: American Chemical Society (ACS)
Date: 21-08-2019
Abstract: Implantable electronics are of great interest owing to their capability for real-time and continuous recording of cellular-electrical activity. Nevertheless, as such systems involve direct interfaces with surrounding biofluidic environments, maintaining their long-term sustainable operation, without leakage currents or corrosion, is a daunting challenge. Herein, we present a thin, flexible semiconducting material system that offers attractive attributes in this context. The material consists of crystalline cubic silicon carbide nanomembranes grown on silicon wafers, released and then physically transferred to a final device substrate (
A Portable Device for LAMP Based Detection of SARS-CoV-2
Publisher: MDPI AG
Date: 24-09-2021
DOI: 10.3390/MI12101151
Abstract: This paper reports the design, development, and testing of a novel, yet simple and low-cost portable device for the rapid detection of SARS-CoV-2. The device performs loop mediated isothermal lification (LAMP) and provides visually distinguishable images of the fluorescence emitted from the s les. The device utilises an aluminium block embedded with a cartridge heater for isothermal heating of the s le and a single-board computer and camera for fluorescence detection. The device demonstrates promising results within 20 min using clinically relevant starting concentrations of the synthetic template. Time-to-signal data for this device are considerably lower compared to standard quantitative Polymerase Chain Reaction(qPCR) machine (~10–20 min vs. min) for 1 × 102 starting template copy number. The device in its fully optimized and characterized state can potentially be used as simple to operate, rapid, sensitive, and inexpensive platform for population screening as well as point-of-need severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) detection and patient management.
Electrohydrodynamic removal of non-specific colloidal adsorption at electrode interfaces
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4CC01357C
Abstract: This communication reports the use of an electrohydrodynamic surface shear force to selectively manipulate colloid–surface interactions. We demonstrate the selection of strongly (specifically) bound biomolecular-functionalized colloidal beads over more weakly (non-specifically) bound beads.
Low-cost electrochemical paper-based device for exosome detection
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2AN00875K
Abstract: A low-cost electrochemical paper-based analytical device was developed to quantify cancer cell-derived exosomes.
Loop-mediated isothermal amplification in a core-shell bead assay for the detection of tyrosine kinase axl overexpression
Publisher: MDPI AG
Date: 30-07-2021
DOI: 10.3390/MI12080905
Abstract: The upregulated expression of tyrosine kinase AXL has been reported in several hematologic and solid human tumors, including gastric, breast, colorectal, prostate and ovarian cancers. Thus, AXL can potentially serve as a diagnostic and prognostic biomarker for various cancers. This paper reports the first ever loop-mediated isothermal lification (LAMP) in a core-shell bead assay for the detection of AXL gene overexpression. We demonstrated simple instrumentation toward a point-of-care device to perform LAMP. This paper also reports the first ever use of core-shell beads as a microreactor to perform LAMP as an attempt to promote environmentally-friendly laboratory practices.
Sensitive Detection of Motor Neuron Disease Derived Exosomal miRNA Using Electrocatalytic Activity of Gold‐Loaded Superparamagnetic Ferric Oxide Nanocubes
Publisher: Wiley
Date: 17-08-2020
Pneumatically actuated cell-stretching array platform for engineering cell patterns in vitro
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7LC01316G
Abstract: We report a pneumatically actuated cell-stretching well array to engineer cell patterns in vitro .
Detection of polymerase chain reaction fragments using a conducting polymer-modified screen-printed electrode in a microfluidic device
Publisher: Wiley
Date: 12-2005
Abstract: A simple and fast method for electrochemical detection of lified fragments by PCR was successfully developed using CE in a microfluidic device with a modified screen-printed carbon electrode (SPCE). The surfaces of the SPCE were modified with poly-5,2'-5',2''-terthiophene-3'-carboxylic acid, which improves the analysis performance by lowering the detection potential, enhancing the S/N characteristics, and avoiding electrode poisoning. DNA fragments lified by PCR were separated within 210 s in a 75.5 mm-long coated-separation channel at a separation field strength of -200 V/cm. To minimize the s le adsorption into the inner surface of the capillary wall, which disturbs the separation, a dynamically coated capillary with an acrylamide solution was used. Furthermore, the analysis procedure was simplified and rendered reproducible by using 0.50% w/v hydroxyethylcellulose as a separation matrix in a coated channel. The reproducibility of the analysis employing the coated channel yielded RSD of 4.3% for the peak areas and 1.4% for the migration times in eight repetitive measurements at a modified electrode, compared with 21.3 and 9.4% for a bare electrode. The sensitivity of the assay was 18.74 pAs/(pg/microL) with a detection limit of 584.31 +/- 1.3 fg/microL.
An amplification-free method for the detection of HOTAIR long non-coding RNA
Publisher: Elsevier BV
Date: 10-2020
MicroRNAs in ovarian cancer and recent advances in the development of microRNA-based biosensors
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9AN02263E
Abstract: Ovarian cancer is the most aggressive of all gynaecological malignancies and is the leading cause of cancer-associated mortality worldwide.
Vanadium‐Substituted Tungstosulfate Polyoxometalates as Peroxidase Mimetics and Their Potential Application in Biosensing
Publisher: Wiley
Date: 06-07-2020
Synthesis of Carbon Nanospheres Through Carbonization of Areca nut
Publisher: American Scientific Publishers
Date: 04-2017
Abstract: We demonstrate a bio-inspired one-pot synthesis of carbon nanospheres with micro-porosity achieved from a promising carbon-rich source (Areca nut) using direct pyrolysis in nitrogen atmosphere at 550 °C in a tube-furnace without adding any catalysts. The resultant carbon spheres are highly monodispersed, uniformly shaped and possess good absorption behaviour (10.5 mg · g−1) for methylene blue (MB).
Naphthalene flanked diketopyrrolopyrrole: a new conjugated building block with hexyl or octyl alkyl side chains for electropolymerization studies and its biosensor applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9PY00430K
Abstract: Naphthalene flanked DPP with hexyl and octyl chain based electropolymerized conjugated polymers exhibits bio-sensing.
FAM134B mutation in esophageal squamous cell carcinoma: Its clinical significance and quantification by electrochemical methods
Publisher: American Association for Cancer Research (AACR)
Date: 07-2017
DOI: 10.1158/1538-7445.AM2017-1243
Abstract: Aim: The aim of this research was to detect novel sites of FAM134B mutations, copy number variations and their clinicopathological significance in esophageal squamous cell carcinoma (ESCC) patients. Also, this study was intended to develop a simple and inexpensive electrochemical detection method for the analysis of FAM134B mutations using a single-use and disposable screen-printed electrode. Method: Approximately 102 fresh tissue s les of ESCC and matched non-cancer adjacent tissues were recruited. The DNA copy numbers of FAM134B were initially studied by qRT-PCR. The FAM134B mutations were then quantified via high resolution melt curve (HRM) and Sanger sequencing analysis. In order to quantify the level of point mutation or SNPs in FAM134B gene, a new electrochemical method was also developed. The underlying working principle of the method is relied on the base dependent affinity interactions towards gold electrode. Since two DNA sequences with different DNA base compositions (i.e., lified mutated sequences will be distinctly different than its wild type sequence) will have different adsorption affinity towards an unmodified gold electrode, accurate measurement of adsorbed DNA on the electrode surface will give the measure of point mutation or SNPs present in the DNA sequences. Target DNA sequences were first extracted from clinical s les and then PCR lified and purified prior to adsorption on a single-use screen-printed gold electrode. The amount of mutation sites on a DNA sequence is quantified by monitoring the Faradaic current generated by the [Fe(CN)6]3-/4- system present in the electrolyte solution. Result: Amplification of FAM134B DNA was noted in 37% of ESCC tissues whereas 35% cases showed loss of FAM134B copies compared to matched non-tumor tissues. Overall, thirty-seven FAM134B mutations were documented in exons 4, 5, 7, 9 as well as introns 2, 4-8 of FAM134B. Also, FAM134B mutations were detected in all the metastatic ESCC cases and in 14% (8/57) of the primary ESCC. Using the new electrochemical method, we were able to detect mutations in 50 ng of target PCR- lified product within 1 h with high reproducibility (% RSD= & ) and specificity. Conclusion: DNA copy number variations and frequent mutations of FAM134B in metastatic lymph node tissues in ESCC patients indicate its critical role in the pathogenesis of ESCCs. Also the mutation detection via electrochemical methods was successful distinguishing single point mutation in DNA from oesophageal cancer implying its potential application in point mutation detection in clinical diagnostics. Note: This abstract was not presented at the meeting. Citation Format: Md. Hakimul Haque, Vinod Gopalan, Muhammad J. A. Shiddiky, Alfred K. Lam. FAM134B mutation in esophageal squamous cell carcinoma: Its clinical significance and quantification by electrochemical methods [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017 2017 Apr 1-5 Washington, DC. Philadelphia (PA): AACR Cancer Res 2017 (13 Suppl):Abstract nr 1243. doi:10.1158/1538-7445.AM2017-1243
Rapid, Simple and Inexpensive Fabrication of Paper-Based Analytical Devices by Parafilm® Hot Pressing
Publisher: MDPI AG
Date: 29-12-2022
DOI: 10.3390/MI13010048
Abstract: Paper-based analytical devices have been substantially developed in recent decades. Many fabrication techniques for paper-based analytical devices have been demonstrated and reported. Herein, we report a relatively rapid, simple, and inexpensive method for fabricating paper-based analytical devices using parafilm hot pressing. We studied and optimized the effect of the key fabrication parameters, namely pressure, temperature, and pressing time. We discerned the optimal conditions, including a pressure of 3.8 MPa, temperature of 80 °C, and 3 min of pressing time, with the smallest hydrophobic barrier size (821 µm) being governed by laminate mask and parafilm dispersal from pressure and heat. Physical and biochemical properties were evaluated to substantiate the paper functionality for analytical devices. The wicking speed in the fabricated paper strips was slightly lower than that of non-processed paper, resulting from a reduced paper pore size after hot pressing. A colorimetric immunological assay was performed to demonstrate the protein binding capacity of the paper-based device after exposure to pressure and heat from the fabrication. Moreover, mixing in a two-dimensional paper-based device and flowing in a three-dimensional counterpart were thoroughly investigated, demonstrating that the paper devices from this fabrication process are potentially applicable as analytical devices for biomolecule detection. Fast, easy, and inexpensive parafilm hot press fabrication presents an opportunity for researchers to develop paper-based analytical devices in resource-limited environments.
μ-eLCR: a microfabricated device for electrochemical detection of DNA base changes in breast cancer cell lines
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3LC50528F
Abstract: Microfabricated devices for the electrochemical detection of single DNA base changes in cancer cell lines are highly desirable due to the inherent advantages such as portability, simplicity, and the rapid and inexpensive nature of electrochemical readout methods. Moreover, molecular sensors that use microscale-footprint working electrodes have shown high signal-to-noise ratio. Herein we report a microdevice-based electrochemical assay (μ-eLCR) measuring ligase chain reaction (LCR)- lified long and short "knife" motifs which reflect the presence or absence of a DNA base change of interest in a target sequence. This μ-eLCR approach has higher sensitivity (4.4 to 10 fold improvement over macrodisk electrodes) and good reproducibility (%RSD 6.5%, n = 12) for the detection of LCR- lified DNA bases. The devices also exhibited excellent sensitivity for the detection of DNA methylation (C to T base change in a locus associated with cancer metastasis) in two cell lines and serum derived DNA s les. We believe that the μ-eLCR device may be a useful diagnostic tool for inexpensive and rapid detection of single DNA base change applications such as DNA methylation and single nucleotide polymorphism (SNP) detection.
Formation of mesopores inside platinum nanospheres by using double hydrophilic block copolymers
Publisher: Elsevier BV
Date: 11-2016
Assisted Reproductive Technology: Advances in Microfluidics-Based Assisted Reproductive Technology: From Sperm Sorter to Reproductive System-on-a-Chip (Adv. Biosys. 3/2018)
Publisher: Wiley
Date: 03-2018
Capture and On-chip analysis of Melanoma Cells Using Tunable Surface Shear forces
Publisher: Springer Science and Business Media LLC
Date: 27-01-2016
DOI: 10.1038/SREP19709
Abstract: With new systemic therapies becoming available for metastatic melanoma such as BRAF and PD-1 inhibitors, there is an increasing demand for methods to assist with treatment selection and response monitoring. Quantification and characterisation of circulating melanoma cells (CMCs) has been regarded as an excellent non-invasive candidate but a sensitive and efficient tool to do these is lacking. Herein we demonstrate a microfluidic approach for melanoma cell capture and subsequent on-chip evaluation of BRAF mutation status. Our approach utilizes a recently discovered alternating current electrohydrodynamic (AC-EHD)-induced surface shear forces, referred to as nanoshearing . A key feature of nanoshearing is the ability to agitate fluid to encourage contact with surface-bound antibody for the cell capture whilst removing nonspecific cells from the surface. By adjusting the AC-EHD force to match the binding affinity of antibodies against the melanoma-associated chondroitin sulphate proteoglycan (MCSP), a commonly expressed melanoma antigen, this platform achieved an average recovery of 84.7% from biological s les. Subsequent staining with anti- BRAF V600E specific antibody enabled on-chip evaluation of BRAF V600E mutation status in melanoma cells. We believe that the ability of nanoshearing -based capture to enumerate melanoma cells and subsequent on-chip characterisation has the potential as a rapid screening tool while making treatment decisions.
Current and future strategies for diagnostic and management of obstructive sleep apnea
Publisher: Informa UK Limited
Date: 24-11-2021
Circulating tumor DNA and liquid biopsy: opportunities, challenges, and recent advances in detection technologies
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8LC00100F
Abstract: Opportunities and challenges in translational application of ctDNA along with recent developments in chip-based ctDNA detection technologies have been reviewed.
Label-free electrochemical detection of an Entamoeba histolytica antigen using cell-free yeast-scFv probes
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2CC38882K
Outstanding Reviewers for Analyst in 2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0AN90052D
Electropolymerized Porous Polymer Films on Flexible Indium Tin Oxide Using Trifunctional Furan Substituted Benzene Conjugated Monomer for Biosensing
Publisher: American Chemical Society (ACS)
Date: 17-01-2020
Electrochemical detection of global dna methylation using biologically assembled polymer beads
Publisher: MDPI AG
Date: 27-07-2021
Abstract: DNA methylation is a cell-type-specific epigenetic marker that is essential for transcriptional regulation, silencing of repetitive DNA and genomic imprinting. It is also responsible for the pathogenesis of many diseases, including cancers. Herein, we present a simple approach for quantifying global DNA methylation in ovarian cancer patient plasma s les based on a new class of biopolymer nanobeads. Our approach utilises the immune capture of target DNA and electrochemical quantification of global DNA methylation level within the targets in a three-step strategy that involves (i) initial preparation of target single-stranded DNA (ss-DNA) from the plasma of the patients’ s les, (ii) direct adsorption of polymer nanobeads on the surface of a bare screen-printed gold electrode (SPE-Au) followed by the immobilisation of 5-methylcytosine (5mC)-horseradish peroxidase (HRP) antibody, and (iii) immune capture of target ss-DNA onto the electrode-bound PHB/5mC-HRP antibody conjugates and their subsequent qualification using the hydrogen peroxide/horseradish peroxidase/hydroquinone (H2O2/HRP/HQ) redox cycling system. In the presence of methylated DNA, the enzymatically produced (in situ) metabolites, i.e., benzoquinone (BQ), binds irreversibly to cellular DNA resulting in the unstable formation of DNA adducts and induced oxidative DNA strand breakage. These events reduce the available BQ in the system to support the redox cycling process and sequel DNA saturation on the platform, subsequently causing high Coulombic repulsion between BQ and negatively charged nucleotide strands. Thus, the increase in methylation levels on the electrode surface is inversely proportional to the current response. The method could successfully detect as low as 5% methylation level. In addition, the assay showed good reproducibility (% RSD ≤ 5%) and specificity by analysing various levels of methylation in cell lines and plasma DNA s les from patients with ovarian cancer. We envision that our bioengineered polymer nanobeads with high surface modification versatility could be a useful alternative platform for the electrochemical detection of varying molecular biomarkers.
Nanoyeast and Other Cell Envelope Compositions for Protein Studies and Biosensor Applications
Publisher: American Chemical Society (ACS)
Date: 04-11-2016
Strategies for Improving the Functionality of Zeolitic Imidazolate Frameworks: Tailoring Nanoarchitectures for Functional Applications
Publisher: Wiley
Date: 18-08-2017
Abstract: Zeolitic imidazolate frameworks (ZIFs), a subclass of metal-organic frameworks (MOFs) built with tetrahedral metal ions and imidazolates, offer permanent porosity and high thermal and chemical stabilities. While ZIFs possess some attractive physical and chemical properties, it remains important to enhance their functionality for practical application. Here, an overview of the extensive strategies which have been developed to improve the functionality of ZIFs is provided, including linker modifications, functional hybridization of ZIFs via the encapsulation of guest species (such as metal and metal oxide nanoparticles and biomolecules) into ZIFs, and hybridization with polymeric matrices to form mixed matrix membranes for industrial gas and liquid separations. Furthermore, the developed strategies for achieving size and shape control of ZIF nanocrystals are considered, which are important for optimizing the textural characteristics as well as the functional performance of ZIFs and their derived materials/hybrids. Moreover, the recent trends of using ZIFs as templates for the derivation of nanoporous hybrid materials, including carbon/metal, carbon/oxide, carbon/sulfide, and carbon hosphide hybrids, are discussed. Finally, some perspectives on the potential future research directions and applications for ZIFs and ZIF-derived materials are offered.
Attributes of direct current aperiodic and alternating current harmonic components derived from large amplitude fourier transformed voltammetry under microfluidic control in a channel electrode
Publisher: American Chemical Society (ACS)
Date: 24-07-2012
DOI: 10.1021/AC3017554
Abstract: The flow rate dependencies of the aperiodic direct current (dc) and fundamental to eighth alternating current (ac) harmonic components derived from large- litude Fourier transformed ac (FT-ac) voltammetry have been evaluated in a microfluidic flow cell containing a 25 μm gold microband electrode. For the oxidation of ferrocenemethanol ([FcMeOH]/[FcMeOH](+) process) in aqueous 0.1 M KNO(3) electrolyte, standard "Levich-like" dc behavior is observed for the aperiodic dc component, which enables the diffusion coefficient for FcMeOH to be obtained. In experimental studies, the first and second ac harmonic components contain contributions from the double layer capacitance current, thereby allowing details of the non-Faradaic current to be established. In contrast, the higher order harmonics and dc aperiodic component are essentially devoid of double layer capacitance contributions allowing the faradaic current dependence on flow rate to be studied. Significantly, flow rate independent data conforming to linear diffusion controlled theory are found in the sixth and higher ac harmonics at a frequency of 15 Hz and for all ac harmonics at a frequency of ≥ 90 Hz. Analysis of FT-ac voltammograms by theory based on stationary microband or planar electrode configurations confirms that stationary microband and planar electrode configurations and experimental data all converge for the higher order harmonics and establishes that the electrode kinetics are very fast (≥1 cms(-1)). The ability to locate, from a single experiment, a dc Faradaic component displaying Levich behavior, fundamental and second harmonics that contain details of the double layer capacitance, and Faradaic ac higher order harmonic currents that are devoid of capacitance, independent of the volume flow rate and also conform closely to mass transport by planar diffusion, provides enhanced flexibility in mass transport and electrode kinetic analysis and in understanding the performance of hydrodynamic electrochemical cells and reactors.
A multiplex microplatform for the detection of multiple DNA methylation events using gold–DNA affinity
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7AN00611J
Abstract: We report a new multiplexed strategy for the electrochemical detection of regional DNA methylation across multiple regions.
e-MagnetoMethyl IP
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1AN00345C
Abstract: e -MagnetoMethyl IP is a new method for electrochemical analysis of global DNA methylation. It avoids bisulfite treatment, PCR lification, and enzyme-based signal generation and can detect differences as low as 5% in global DNA methylation levels.
Nanostructured mesoporous gold biosensor for microRNA detection at attomolar level
Publisher: Elsevier BV
Date: 11-2020
Cancer biomarker profiling using nanozyme containing iron oxide loaded with gold particles
Publisher: The Royal Society
Date: 06-2020
Abstract: Nanozymes are nanomaterials with intrinsic magnetism and superparamagnetic properties. In the presence of an external magnet, nanozyme particles aggregate and redisperse without a foreign attraction. We evaluated the performances of nanozyme by changing the biosensing platforms and substituting other biological variants for a complete cancer assay detection. We investigated the expression of morphological variants in the transmission of signals using an electrochemical method. The signal responses, including signal enhancement with the nanozyme (Au-Fe 2 O 3 ), showed a wide capturing range (greater than 80%, from 10 2 to 10 5 cells ml −1 in phosphate-buffered saline buffer, pH 7.4). The platform showed a fast response time within a dynamic range of 10–10 5 cells ml −1 for the investigated T47D cancer cell line. We also obtained higher responses for anti-HER2 (human epidermal receptor 2)/streptavidin interface as the biosensing electrode in the presence of T47D cancer cells. The positive assay produced a sixfold increase in current output compared to the negative target or negative biological variant. We calculated the limit of detection at 0.4 U ml −1 , and of quantitation at 4 U ml −1 (units per millilitre). However, blood volume amounts in clinical settings may constrain diagnosis and increase detection limit value significantly.
Molecular inversion probe-based SPR biosensing for specific, label-free and real-time detection of regional DNA methylation
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CC49607D
Abstract: DNA regional methylation can be detected in real-time and label-free using surface plasmon resonance biosensing coupled to molecular inversion probe based lification.
A lactate biosensor based on lactate dehydrogenase/nictotinamide adenine dinucleotide (oxidized form) immobilized on a conducting polymer/multiwall carbon nanotube composite film
Publisher: Elsevier BV
Date: 2009
Abstract: An erometric lactate biosensor was developed based on a conducting polymer, poly-5,2'-5',2''-terthiophene-3'-carboxylic acid (pTTCA), and multiwall carbon nanotube (MWNT) composite on a gold electrode. Lactate dehydrogenase (LDH) and the oxidized form of nicotinamide adenine dinucleotide (NAD(+)) were subsequently immobilized onto the pTTCA/MWNT composite film. The modified electrode was characterized by quartz crystal microbalance (QCM), scanning electron microscopy (SEM), and electrochemical experiments. The detection signal was lified by the pTTCA/MWNT assembly onto which a sufficient amount of enzyme was immobilized and stabilized by the covalent bond formation between the amine groups of enzyme and the carboxylic acid groups of the pTTCA/MWNT film. Experimental parameters affecting the sensor responses, such as applied potential, pH, and temperature, were assessed and optimized. Analytical performances and dynamic ranges of the sensor were determined, and the results showed that the sensitivity, stability, and reproducibility of the sensor improved significantly using pTTCA/MWNT composite film. The calibration plot was linear (r(2)=0.9995) over the range of 5 to 90 microM. The sensitivity was approximately 0.0106 microA/microM, with a detection limit of 1 microM, based on a signal/noise ratio of 3. The applicability of the sensor for the analysis of l-lactate concentration in commercial milk and human serum s les was demonstrated successfully.
Tuneable surface shear forces to physically displace nonspecific molecules in protein biomarker detection
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1016/J.BIOS.2014.03.061
Abstract: We report a simple method to remove nonspecifically adsorbed species from sensor surface and also improve the detection sensitivity of the sensor using tuneable alternating current (ac) electrohydrodynamics (ac-EHD) forces. These forces generated within few nanometers of an electrode surface (i.e., double layer) engender fluid flow within a serpentine channel containing a long array of the asymmetric electrode pairs, and can easily be tuned externally by changing the frequency and litude of the ac-EHD field. Under the optimized experimental conditions, we achieved a 3.5-fold reduction in nonspecific adsorption of non-target proteins with a 1000-fold enhancement in detection sensitivity of the device for the analysis of human epidermal growth factor receptor 2 (HER2) protein spiked in serum. This approach can be applicable in erse fields including biosensors, cellular and molecular separation systems and biomedical applications to remove/reduce nonspecific adsorption of molecular and cellular species.
PCR‐free detection of long non‐coding HOTAIR RNA in ovarian cancer cell lines and plasma samples
Publisher: MDPI AG
Date: 10-08-2020
Abstract: Long non-coding RNA HOX transcript antisense intergenic RNA (HOTAIR) is one of the promising biomarkers that has widely been used in determining the stages of many cancers, including ovarian cancer. In cancer diagnostics, the two key analytical challenges for detecting long non-coding RNA biomarkers are i) the low concentration levels (nM to fM range) in which they are found and ii) the analytical method where broad dynamic range is required (four to six orders of magnitude) due to the large variation in expression levels for different HOTAIR RNAs. To meet these challenges, we report on a biosensing platform for the visual (colorimetric) estimation and subsequent electrochemical quantification of ovarian-cancer-specific HOTAIR using a screen-printed gold electrode (SPE-Au). Our assay utilizes a two-step strategy that involves (i) magnetic isolation and purification of target HOTAIR sequences and (ii) subsequent detection of isolated sequences using a sandwich hybridization coupled with horseradish peroxidase (HRP)-catalyzed reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. The assay achieved a detection limit of 1.0 fM HOTAIR in spiked buffer s les with excellent reproducibility (% RSD ≤ 5%, for n = 3). It was successfully applied to detect HOTAIR in cancer cell lines and a panel of plasma s les derived from patients with ovarian cancer. The analytical performance of the method was validated with standard RT-qPCR. We believe that the proof of concept assay reported here may find potential use in routine clinical settings for the screening of cancer-related lncRNAs.
Duplex Microfluidic SERS Detection of Pathogen Antigens with Nanoyeast Single-Chain Variable Fragments
Publisher: American Chemical Society (ACS)
Date: 18-09-2014
DOI: 10.1021/AC5027012
Identification of Novel FAM134B (JK1) Mutations in Oesophageal Squamous Cell Carcinoma
Publisher: Springer Science and Business Media LLC
Date: 04-07-2016
DOI: 10.1038/SREP29173
Abstract: Mutation of FAM134B ( Family with Sequence Similarity 134, Member B ) leading to loss of function of its encoded Golgi protein and has been reported induce apoptosis in neurological disorders. FAM134B mutation is still unexplored in cancer. Herein, we studied the DNA copy number variation and novel mutation sites of FAM134B in a large cohort of freshly collected oesophageal squamous cell carcinoma (ESCC) tissue s les. In ESCC tissues, 37% (38/102) showed increased FAM134B DNA copies whereas 35% (36/102) showed loss of FAM134B copies relative to matched non-cancer tissues. Novel mutations were detected in exons 4, 5, 7, 9 as well as introns 2, 4-8 of FAM134B via HRM (High-Resolution Melt) and Sanger sequencing analysis. Overall, thirty-seven FAM134B mutations were noted in which most (31/37) mutations were homozygous. FAM134B mutations were detected in all the cases with metastatic ESCC in the lymph node tested and in 14% (8/57) of the primary ESCC. Genetic alteration of FAM134B is a frequent event in the progression of ESCCs. These findings imply that mutation might be the major driving source of FAM134B genetic modulation in ESCCs.
Toward Personalized Nanomedicine: The Critical Evaluation of Micro and Nanodevices for Cancer Biomarker Analysis in Liquid Biopsy
Publisher: Wiley
Date: 11-01-2023
Abstract: Liquid biopsy for the analysis of circulating cancer biomarkers (CBs) is a major advancement toward the early detection of cancer. In comparison to tissue biopsy techniques, liquid biopsy is relatively painless, offering multiple s ling opportunities across easily accessible bodily fluids such as blood, urine, and saliva. Liquid biopsy is also relatively inexpensive and simple, avoiding the requirement for specialized laboratory equipment or trained medical staff. Major advances in the field of liquid biopsy are attributed largely to developments in nanotechnology and microfabrication that enables the creation of highly precise chip‐based platforms. These devices can overcome detection limitations of an in idual biomarker by detecting multiple markers simultaneously on the same chip, or by featuring integrated and combined target separation techniques. In this review, the major advances in the field of portable and semi‐portable micro, nano, and multiplexed platforms for CB detection for the early diagnosis of cancer are highlighted. A comparative discussion is also provided, noting merits and drawbacks of the platforms, especially in terms of portability. Finally, key challenges toward device portability and possible solutions, as well as discussing the future direction of the field are highlighted.
Vanadium‐Substituted Tungstosulfate Polyoxometalates as Peroxidase Mimetics and Their Potential Application in Biosensing
Publisher: Wiley
Date: 09-2020
Loop-Mediated Isothermal Amplification in Core-Shell Beads Assay for the Detection of Tyrosine Kinase AXL Over Expression
Publisher: MDPI AG
Date: 08-07-2021
DOI: 10.20944/PREPRINTS202107.0195.V1
Abstract: The upregulated expression of thyrosine kinase AXL has been reported in several hematologic and solid human tumors including gastric, breast, colorectal, prostate, and ovarian cancers. Thus, AXL can potentially serve as a diagnostic and prognostic biomarker for various cancers. This paper reports the first-ever use of loop-mediated isothermal lification (LAMP) of the AXL gene as a diagnostic method for ovarian cancer. We demonstrated simple instrumentation toward a point-of-care device to perform LAMP. This paper also reports the first-ever use of core-shell beads as a microreactor to perform LAMP as an attempt to promote environmentally friendly laboratory practices.
Homogeneous Electron-Transfer Reaction between Electrochemically Generated Ferrocenium Ions and Amine-Containing Compounds
Publisher: American Chemical Society (ACS)
Date: 30-04-2013
DOI: 10.1021/OM4002318
Analysis of polymerase chain reaction amplifications through phosphate detection using an enzyme–based microbiosensor in a microfluidic device
Publisher: Wiley
Date: 07-2006
Abstract: An electrochemical method was developed for analyzing PCR lification through the detection of inorganic phosphates (Pi). This method coupled a microchip to a nanoparticle comprising poly-5,2'-5',2''-terthiophene-3'-carboxylic acid (poly-TTCA) yruvate oxidase (PyO) modified microbiosensor. It detects Pi produced from the pyrophosphate (PPi), which is released as a byproduct of PCR. After completion of PCR, PPi is hydrolyzed to Pi by inorganic pyrophosphatase. On the microbiosensor surface, pyruvate was converted to H2O2 by PyO in the presence of Pi and oxygen, and subsequently, the anodic current of enzymatically generated H2O2 was detected at +0.5 V versus Ag/AgCl. The CE-EC analysis was completed within 2 min in a coated channel with 75.0 mm separation length at the field strength of -200 V/cm. Excellent operation stability of poly-TTCA/PyO was observed for a long period of analysis. The reproducibility of the analysis yielded an RSD of 3.4% (n = 22) for the peak areas and 1.8% (n = 22) for the migration times. The sensitivity of the analysis was 0.59 +/- 0.01 nA/cycle with a regression coefficient of 0.971.
Colorimetric and electrochemical quantification of global DNA methylation using a methyl cytosine-specific antibody
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7AN00526A
Abstract: We report a simple colorimetric (naked-eye) and electrochemical method for the rapid, sensitive and specific quantification of global methylation levels using only 25 ng of input DNA.
Epigenetically reprogrammed methylation landscape drives the DNA self-assembly and serves as a universal cancer biomarker
Publisher: Springer Science and Business Media LLC
Date: 04-12-2018
DOI: 10.1038/S41467-018-07214-W
Abstract: Epigenetic reprogramming in cancer genomes creates a distinct methylation landscape encompassing clustered methylation at regulatory regions separated by large intergenic tracks of hypomethylated regions. This methylation landscape that we referred to as Methylscape is displayed by most cancer types, thus may serve as a universal cancer biomarker. To-date most research has focused on the biological consequences of DNA Methylscape changes whereas its impact on DNA physicochemical properties remains unexplored. Herein, we examine the effect of levels and genomic distribution of methylcytosines on the physicochemical properties of DNA to detect the Methylscape biomarker. We find that DNA polymeric behaviour is strongly affected by differential patterning of methylcytosine, leading to fundamental differences in DNA solvation and DNA-gold affinity between cancerous and normal genomes. We exploit these Methylscape differences to develop simple, highly sensitive and selective electrochemical or colorimetric one-step assays for the detection of cancer. These assays are quick, i.e., analysis time ≤10 minutes, and require minimal s le preparation and small DNA input.
Femtomolar detection of a cancer biomarker protein in serum with ultralow background current by anodic stripping voltammetry
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC32810K
Abstract: An electrochemical immunosensor for the detection of a cancer biomarker protein in serum at femtomolar concentrations with ultralow background response has been developed, which consists of (i) a hydrophilic polyacrylic acid brush-modified indium tin oxide substrate as an antifouling substrate and (ii) a graphene-quantum dots-antibody 'bionanoconjugate' as a signal lification label in voltammetric detection of targets in a glassy carbon electrode.
Methylsorb: A simple method for quantifying DNA methylation using DNA-gold affinity interactions
Publisher: IEEE
Date: 12-2015
A PCR-free electrochemical method for messenger RNA detection in cancer tissue samples
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.BIOS.2017.06.051
Abstract: Despite having reliable and excellent diagnostic performances, the currently available messenger RNA (mRNA) detection methods mostly use enzymatic lification steps of the target mRNA which is generally affected by the s le manipulations, lification bias and longer assay time. This paper reports an lification-free electrochemical approach for the sensitive and selective detection of mRNA using a screen-printed gold electrode (SPE-Au). The target mRNA is selectively isolated by magnetic separation and adsorbed directly onto an unmodified SPE-Au. The surface-attached mRNA is then measured by differential pulse voltammetry (DPV) in the presence of [Fe(CN)
Circulating tumor microemboli: Progress in molecular understanding and enrichment technologies
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.BIOTECHADV.2018.05.002
Abstract: Circulating tumor cells (CTCs) and their clusters, also known as circulating tumor microemboli (CTM), have emerged as valuable tool that can provide mechanistic insights into the tumor heterogeneity, clonal evolution, and stochastic events within the metastatic cascade. However, recent investigations have hinted that CTM may not be mere aggregates of tumor cells but cells comprising CTM exhibit distinct phenotypic and molecular characteristics in comparison to single CTCs. Moreover, in many cases CTM demonstrated higher metastatic potential and resistance to apoptosis as compared to their single cell counterparts. Thus, their evaluation and enumeration may provide a new dimension to our understanding of cancer biology and metastatic cancer spread as well as offer novel theranostic biomarkers. Most of the existing technologies for isolation of hematogenous tumor cells largely favor single CTCs, hence there is a need to devise new approaches, or re-configure the existing ones, for specific and efficient CTM isolation. Here we review existing knowledge and insights on CTM biology. Furthermore, a critical commentary on current and emerging trends in CTM enrichment and characterization along with recently developed ex-vivo CTC expansion methodologies is presented with the aim to facilitate researchers to identify further avenues of research and development.
Biosensor Technologies for Early Detection and Quantification of Plant Pathogens
Publisher: Frontiers Media SA
Date: 02-06-2021
DOI: 10.3389/FCHEM.2021.636245
Abstract: Plant pathogens are a major reason of reduced crop productivity and may lead to a shortage of food for both human and animal consumption. Although chemical control remains the main method to reduce foliar fungal disease incidence, frequent use can lead to loss of susceptibility in the fungal population. Furthermore, over-spraying can cause environmental contamination and poses a heavy financial burden on growers. To prevent or control disease epidemics, it is important for growers to be able to detect causal pathogen accurately, sensitively, and rapidly, so that the best practice disease management strategies can be chosen and enacted. To reach this goal, many culture-dependent, biochemical, and molecular methods have been developed for plant pathogen detection. However, these methods lack accuracy, specificity, reliability, and rapidity, and they are generally not suitable for in-situ analysis. Accordingly, there is strong interest in developing biosensing systems for early and accurate pathogen detection. There is also great scope to translate innovative nanoparticle-based biosensor approaches developed initially for human disease diagnostics for early detection of plant disease-causing pathogens. In this review, we compare conventional methods used in plant disease diagnostics with new sensing technologies in particular with deeper focus on electrochemical and optical biosensors that may be applied for plant pathogen detection and management. In addition, we discuss challenges facing biosensors and new capability the technology provides to informing disease management strategies.
Nanozyme-based electrochemical biosensors for disease biomarker detection
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0AN00558D
Abstract: In this review, we have summarised the synthesis and classification of common nanozymes and their applications in electrochemical biosensor development.
Alternating Current Electrohydrodynamics Induced Nanoshearing and Fluid Micromixing for Specific Capture of Cancer Cells
Publisher: Wiley
Date: 23-02-2014
Abstract: We report a new tuneable alternating current (ac) electrohydrodynamics (ac-EHD) force referred to as “nanoshearing” which involves fluid flow generated within a few nanometers of an electrode surface. This force can be externally tuned via manipulating the applied ac-EHD field strength. The ability to manipulate ac-EHD induced forces and concomitant fluid micromixing can enhance fluid transport within the capture domain of the channel (e.g., transport of analytes and hence increase target–sensor interactions). This also provides a new capability to preferentially select strongly bound analytes over nonspecifically bound cells and molecules. To demonstrate the utility and versatility of nanoshearing phenomenon to specifically capture cancer cells, we present proof-of-concept data in lysed blood using two microfluidic devices containing a long array of asymmetric planar electrode pairs. Under the optimal experimental conditions, we achieved high capture efficiency (e.g., approximately 90% %RSD=2, n=3) with a 10-fold reduction in nonspecific adsorption of non-target cells for the detection of whole cells expressing Human Epidermal Growth Factor Receptor 2 (HER2). We believe that our ac-EHD devices and the use of tuneable nanoshearing phenomenon may find relevance in a wide variety of biological and medical applications.
Structural Characterization of Nanoyeast Single-Chain Fragment Variable Affinity Reagents
Publisher: American Chemical Society (ACS)
Date: 22-05-2015
An electrochemical method for sensitive and rapid detection of FAM134B protein in colon cancer samples
Publisher: Springer Science and Business Media LLC
Date: 09-03-2017
DOI: 10.1038/S41598-017-00206-8
Abstract: Despite the excellent diagnostic applications of the current conventional immunoassay methods such as ELISA, immunostaining and Western blot for FAM134B detection, they are laborious, expensive and required a long turnaround time. Here, we report an electrochemical approach for rapid, sensitive, and specific detection of FAM134B protein in biological (colon cancer cell extracts) and clinical (serum) s les. The approach utilises a differential pulse voltammetry (DPV) in the presence of the [Fe(CN) 6 ] 3−/4− redox system to quantify the FAM134B protein in a two-step strategy that involves ( i ) initial attachment of FAM134B antibody on the surface of extravidin-modified screen-printed carbon electrode, and ( ii ) subsequent detection of FAM134B protein present in the biological/clinical s les. The assay system was able to detect FAM134B protein at a concentration down to 10 pg μL −1 in phosphate buffered saline (pH 7.4) with a good inter-assay reproducibility (% RSD = .64, n = 3). We found excellent sensitivity and specificity for the analysis of FAM134B protein in a panel of colon cancer cell lines and serum s les. Finally, the assay was further validated with ELISA method. We believe that our assay could potentially lead a low-cost alternative to conventional immunological assays for target antigens analysis in point-of-care applications.
Conditions Favoring the Formation of Monomeric PtIIIDerivatives in the Electrochemical Oxidation oftrans-[PtII{(p-BrC6F4)NCH2CH
Publisher:
Wiley
Date:
21-04-2015
Publisher: Wiley
Date: 21-04-2015
Amplification-Free Detection of Gene Fusions in Prostate Cancer Urinary Samples Using mRNA–Gold Affinity Interactions
Publisher: American Chemical Society (ACS)
Date: 23-06-2016
DOI: 10.1021/ACS.ANALCHEM.6B01182
Abstract: A crucial issue in present-day prostate cancer (PCa) detection is the lack of specific biomarkers for accurately distinguishing between benign and malignant cancer forms. This is causing a high degree of overdiagnosis and overtreatment of otherwise clinically insignificant cases. As around half of all malignant PCa cases display a detectable gene fusion mutation between the TMPRSS2 promoter sequence and the ERG coding sequence (TMPRSS2:ERG) in urine, noninvasive screening of TMPRSS2:ERG mRNA in patient urine s les could improve the specificity of current PCa diagnosis. However, current gene fusion detection methodologies are largely dependent on RNA enzymatic lification, which requires extensive s le manipulation, costly labels for detection, and is prone to bias/artifacts. Herein we introduce the first successful lification-free electrochemical assay for direct detection of TMPRSS2:ERG mRNA in PCa urinary s les by selectively isolating and adsorbing TMPRSS2:ERG mRNA onto bare gold electrodes without requiring any surface modification. We demonstrated excellent limit-of-detection (10 cells) and specificity using PCa cell line models, and showcased clinical utility by accurately detecting TMPRSS2:ERG in a collection of 17 urinary s les obtained from PCa patients. Furthermore, these results were validated with the current gold standard reverse transcription (RT)-PCR approach with 100% concordance.
Optical biosensing strategies for DNA methylation analysis
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.BIOS.2016.10.034
Abstract: DNA methylation is an epigenetic modification of DNA, where a methyl group is added at the fifth carbon of the cytosine base to form 5 methyl cytosine (5mC) without altering the DNA sequences. It plays important roles in regulating many cellular processes by modulating key genes expression. Alteration in DNA methylation patterns becomes particularly important in the aetiology of different diseases including cancers. Abnormal methylation pattern could contribute to the pathogenesis of cancer either by silencing key tumor suppressor genes or by activating oncogenes. Thus, DNA methylation biosensing can help in the better understanding of cancer prognosis and diagnosis and aid the development of therapies. Over the last few decades, a plethora of optical detection techniques have been developed for analyzing DNA methylation using fluorescence, Raman spectroscopy, surface plasmon resonance (SPR), electrochemiluminescence and colorimetric readouts. This paper aims to comprehensively review the optical strategies for DNA methylation detection. We also present an overview of the remaining challenges of optical strategies that still need to be focused along with the lesson learnt while working with these techniques.
Reduced graphene oxide nanofluidic electrolyte with improved electrochemical properties for vanadium flow batteries
Publisher: Elsevier BV
Date: 05-2022
Microfluidic Technology for the Generation of Cell Spheroids and Their Applications
Publisher: MDPI AG
Date: 23-03-2017
DOI: 10.3390/MI8040094
Graphene-Oxide-Loaded Superparamagnetic Iron Oxide Nanoparticles for Ultrasensitive Electrocatalytic Detection of MicroRNA
Publisher: Wiley
Date: 27-06-2018
Front Cover: Vanadium‐Substituted Tungstosulfate Polyoxometalates as Peroxidase Mimetics and Their Potential Application in Biosensing (ChemElectroChem 19/2020)
Publisher: Wiley
Date: 31-08-2020
Potential Transcription Factors for Biotic Stress Tolerance in Sugarcanee
Publisher: Springer International Publishing
Date: 2022
Magnetic nanomaterial–based electrochemical biosensors for the detection of diverse circulating cancer biomarkers
Publisher: Elsevier BV
Date: 02-2021
Alternating current electrohydrodynamics in microsystems: Pushing biomolecules and cells around on surfaces
Publisher: AIP Publishing
Date: 11-2015
DOI: 10.1063/1.4936300
Abstract: Electrohydrodynamics (EHD) deals with the fluid motion induced by an electric field. This phenomenon originally developed in physical science, and engineering is currently experiencing a renaissance in microfluidics. Investigations by Taylor on Gilbert's theory proposed in 1600 have evolved to include multiple contributions including the promising effects arising from electric field interactions with cells and particles to influence their behaviour on electrode surfaces. Theoretical modelling of electric fields in microsystems and the ability to determine shear forces have certainly reached an advanced state. The ability to deftly manipulate microscopic fluid flow in bulk fluid and at solid/liquid interfaces has enabled the controlled assembly, coagulation, or removal of microstructures, nanostructures, cells, and molecules on surfaces. Furthermore, the ability of electrohydrodynamics to generate fluid flow using surface shear forces generated within nanometers from the surface and their application in bioassays has led to recent advancements in biomolecule, vesicle and cellular detection across different length scales. With the integration of Alternating Current Electrohydrodynamics (AC-EHD) in cellular and molecular assays proving to be highly fruitful, challenges still remain with respect to understanding the discrepancies between each of the associated ac-induced fluid flow phenomena, extending their utility towards clinical diagnostic development, and utilising them in tandem as a standard tool for disease monitoring. In this regard, this article will review the history of electrohydrodynamics, followed by some of the recent developments in the field including a new dimension of electrohydrodynamics that deals with the utilization of surface shear forces for the manipulation of biological cells or molecules on electrode surfaces. Recent advances and challenges in the use of electrohydrodynamic forces such as dielectrophoresis and ac electrosmosis for the detection of biological analytes are also reviewed. Additionally, the fundamental mechanisms of fluid flow using electrohydrodynamics forces, which are still evolving, are reviewed. Challenges and future directions are discussed from the perspective of both fundamental understanding and potential applications of these nanoscaled shear forces in diagnostics.
RNA Biomarkers: Diagnostic and Prognostic Potentials and Recent Developments of Electrochemical Biosensors
Publisher: Wiley
Date: 05-06-2017
Electrooxidation of [(η5-C5H5)Fe(CO)2]2 As a Probe of the Nucleophilic Properties of Ionic Liquid Anions
Publisher: American Chemical Society (ACS)
Date: 02-2010
DOI: 10.1021/IC9025238
Abstract: The oxidative electrochemistry of [CpFe(CO)(2)](2), 1 (Cp = [eta(5)-C(5)H(5)](-)), was examined in detail in ionic liquids (ILs) composed of ions of widely varying Lewis acid-base properties. Cyclic voltammetric responses were strongly dependent on the nucleophilic properties of the IL anion, but all observations are consistent with the initial formation of 1(+) followed by attack from the IL anion. In [NTf(2)](-)-based ILs ([NTf(2)](-) = bis(trifluoromethylsulfonyl)amide), the process shows nearly ideal chemical reversibility as the reaction between 1(+) and [NTf(2)](-) is very slow. This is highly significant, as 1(+) is known to be highly susceptible to nucleophilic attack and its stability indicates a remarkable lack of coordinating ability of these ILs. In 1-methyl-3-butylimidazolium hexafluorophosphate, [bmim][PF(6)], the oxidation of 1 is still largely reversible, but there is more pronounced evidence of [PF(6)](-) coordination. In contrast, 1 exhibits an irreversible two-electron oxidation process in a dicyanamide-based IL. This overall oxidation process is thought to proceed via an ECE mechanism, details of which are presented. Rate constants were estimated by fitting the experimental data to digital simulations of the proposed mechanism. The use of [NTf(2)](-)-based ILs as a supporting electrolyte in CH(2)Cl(2) was examined by using this solvent/electrolyte as a medium in which to perform bulk electrolyses of 1 and 1*, the permethylated analogue [Cp*Fe(CO)(2)](2) (Cp* = [eta(5)-C(5)(CH(3))(5)](-)). These cleanly yielded the corresponding binuclear radical-cation species, 1(+) and 1*(+), which were subsequently characterized by electron paramagnetic resonance (EPR) spectroscopy. In addition to the above oxidation studies, the reduction of 1 was studied in each of the ILs differences in cathodic peak potentials are attributed, in part, to ion-pairing effects. This study illustrates the wide range of electrochemical environments available with ILs and demonstrates their utility for the investigation of the redox properties of metal carbonyls and other organometallic compounds.
Electrophoretic analysis of food dyes using a miniaturized microfluidic system
Publisher: Wiley
Date: 05-2008
Abstract: A simple and sensitive on-chip preconcentration, separation, and electrochemical detection (ED) method for the electrophoretic analysis of food dyes was developed. The microchip comprised of three parallel channels: the first two are for the field- lified s le stacking (FASS) and subsequent field- lified s le injection (FASI) steps, while the third one is for the micellar EKC with ED (MEKC-ED) step. The food dyes were initially extracted from real s les by employing a method that was simpler, easier, and faster compared with a standard method. The extraction of the s les was characterized by UV-Vis and electrochemical experiments. The chrono erometric detection was performed with a glassy carbon electrode coupled horizontally with the microchip at the separation channel exit. Experimental parameters affecting the analytical performance of the method were assessed and optimized. The sensitivity of the method was improved by approximately 10,800-fold when compared with a conventional MEKC-ED analysis. Reproducible response was observed during multiple injections of s les with an RSD of <7.2% (n=5). The calibration plots were linear (r2=0.998) within the range of 1.0 nM-1.0 microM for all food dyes. LODs were estimated between 1.0 and 5.0 nM, based on S/N=3, for food dyes. The applicability of the method for the analysis of food dyes in real s le was demonstrated.
Development of Extraction and Analytical Methods of Nitrite Ion from Food Samples: Microchip Electrophoresis with a Modified Electrode
Publisher: American Chemical Society (ACS)
Date: 17-04-2009
DOI: 10.1021/JF900230X
Abstract: Two simple and fast methods for the extraction of the nitrite ion (NO(2)(-)) from food s les have been developed. The methods were characterized by UV-visible spectroscopic and electrochemical measurements, and their performance for NO(2)(-) extraction was compared with a standard method. The extraction methods yielded relative recoveries between 100 and 120% with good reproducibility of 3.9% (RSD, n = 4) in UV-visible experiments. Microchip electrophoresis with electrochemical detection (MCE-ED) coupled with a copper (3-mercaptopropyl)trimethoxysilane [Cu(II)-MPS] complex-modified carbon paste electrode (CPE) has been employed to detect NO(2)(-) in extracted s les. The Cu(II)-MPS complex was synthesized and characterized by voltammetry, XPS, and FT-IR analyses. Experimental parameters affecting the separation and detection performances of the MCE-ED method were assessed and optimized. The potential for the electrocatalytic reduction of NO(2)(-) for MCE-ED was found to be -190 mV (vs Ag/AgCl). When extracted food s les were analyzed by the MCE-ED method, a reproducible response for the NO(2)(-) reduction (RSD of 4.3%) at the modified-CPE reflected the negligible electrode fouling. A wide dynamic range of 1.0-160 ppm was observed for analyzing standard NO(2)(-) with a sensitivity of 0.05106 ± 0.00141, and the detection limit, based on S/N = 3, was found to be 0.35 ± 0.05 ppm. No apparent interference from NO(3)(-), other inorganic ions, and biological compounds was observed under the optimal experimental conditions. A standard addition method for real s les showed wide concentration ranges of 1.10-155 and 1.2-150 ppm for analyzing NO(2)(-) in ham and sausage s les, respectively.
Editorial: Advances in Nucleic Acid-Based Biosensors and Imaging
Publisher: Frontiers Media SA
Date: 24-05-2022
Direct Analysis of Trace Phenolics with a Microchip: In-Channel Sample Preconcentration, Separation, and Electrochemical Detection
Publisher: American Chemical Society (ACS)
Date: 09-2006
DOI: 10.1021/AC0606002
Abstract: A micrototal analytical method assembling in-channel preconcentration, separation, and electrochemical detection steps has been developed for trace phenolic compounds. A micellar electrokinetic chromatography separation technique was coupled with two preconcentration steps of field- lified s le stacking (FASS) and field- lified s le injection (FASI). An erometric detection method with a cellulose-dsDNA-modified, screen-printed carbon electrode was applied to detect preconcentrated and separated species at the end of the channel. The microchip was composed of three parallel channels: first, two are for the s le preconcentration using FASS and FASI methods, and the third one is for the separation and electrochemical detection. The modification of the electrode surface improved the detection performance by enhancing the signal-to-noise characteristic without surface fouling of the electrode. The method was examined for the analysis of eight phenolic compounds. Experimental parameters affecting the analytical performance of the method were assessed and optimized. The preconcentration factor was increased by about 5200-fold as compared with a simple capillary zone electrophoretic analysis using the same channel. Reproducible response was observed during multiple injections of s les with a RSD of <8.0%. The calibration plots were shown to be linear (with the correlation coefficient between 0.9913 and 0.9982) over the range of 0.4-600 nM. The sensitivity was between 0.17 +/- 0.001 and 0.48 +/- 0.006 nA/nM, with the detection limit of approximately 100 to approximately 150 pM based on S/N = 3. The applicability of the method to the direct analysis of trace phenolic compounds in water s les was successfully demonstrated.
Avoiding Pre-Isolation Step in Exosome Analysis: Direct Isolation and Sensitive Detection of Exosomes Using Gold-Loaded Nanoporous Ferric Oxide Nanozymes
Publisher: American Chemical Society (ACS)
Date: 08-02-2019
DOI: 10.1021/ACS.ANALCHEM.8B03619
Abstract: Most of the current exosome-analysis strategies are time-consuming and largely dependent on commercial extraction kit-based preisolation step, which requires extensive s le manipulations, costly isolation kits, reagents, tedious procedures, and sophisticated equipment and is prone to bias/artifacts. Herein we introduce a simple method for direct isolation and subsequent detection of a specific population of exosomes using an engineered superparamagnetic material with multifunctional properties, namely, gold-loaded ferric oxide nanocubes (Au-NPFe
Core-Shell Beads Made by Composite Liquid Marble Technology as A Versatile Microreactor for Polymerase Chain Reaction
Publisher: MDPI AG
Date: 26-02-2020
DOI: 10.3390/MI11030242
Abstract: Over the last three decades, the protocols and procedures of the DNA lification technique, polymerase chain reaction (PCR), have been optimized and well developed. However, there have been no significant innovations in processes for s le dispersion for PCR that have reduced the amount of single-use or unrecyclable plastic waste produced. To address the issue of plastic waste, this paper reports the synthesis and successful use of a core-shell bead microreactor using photopolymerization of a composite liquid marble as a dispersion process. This platform uses the core-shell bead as a simple and effective s le dispersion medium that significantly reduces plastic waste generated compared to conventional PCR processes. Other improvements over conventional PCR processes of the novel dispersion platform include increasing the throughput capability, enhancing the performance and portability of the thermal cycler, and allowing for the contamination-free storage of s les after thermal cycling.
An Electromagnetically Actuated Double-Sided Cell-Stretching Device for Mechanobiology Research
Publisher: MDPI AG
Date: 22-08-2017
DOI: 10.3390/MI8080256
Drill and fill lithography: fabrication of platinum electrodes and their use in label-free immunosensing
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3RA21900C
Advanced diagnostic approaches for necrotrophic fungal pathogens of temperate legumes with a focus on botrytis spp.
Publisher: Frontiers Media SA
Date: 14-08-2019
Transparent crystalline cubic SiC-on-glass electrodes enable simultaneous electrochemistry and optical microscopy
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC03082D
Abstract: This work introduces transparent SiC-on-glass as a new platform for biosensing applications which enables cell culturing, stimulating, microscopy-imaging and bioelectrochemical detection.
Mesoporous Iron Oxide Synthesized Using Poly(styrene-b-acrylic acid-b-ethylene glycol) Block Copolymer Micelles as Templates for Colorimetric and Electrochemical Detection of Glucose
Publisher: American Chemical Society (ACS)
Date: 19-12-2017
Abstract: Herein, we report the soft-templated preparation of mesoporous iron oxide using an asymmetric poly(styrene-b-acrylic acid-b-ethylene glycol) (PS-b-PAA-b-PEG) triblock copolymer. This polymer forms a micelle consisting of a PS core, a PAA shell, and a PEG corona in aqueous solutions, which can serve as a soft template. The mesoporous iron oxide obtained at an optimized calcination temperature of 400 °C exhibited an average pore diameter of 39 nm, with large specific surface area and pore volume of 86.9 m
Application of ionic liquids in electrochemical sensing systems
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.BIOS.2010.08.064
Abstract: Since 1992, when the room temperature ionic liquids (ILs) based on the 1-alkyl-3-methylimidazolium cation were reported to provide an attractive combination of an electrochemical solvent and electrolyte, ILs have been widely used in electrodeposition, electrosynthesis, electrocatalysis, electrochemical capacitor, and lithium batteries. However, it has only been in the last few years that electrochemical biosensors based on carbon ionic liquid electrodes (CILEs) and IL-modified macrodisk electrodes have been reported. However, there are still a lot of challenges in achieving IL-based sensitive, selective, and reproducible biosensors for high speed analysis of biological and environmental compounds of interest. This review discusses the principles of operation of electrochemical biosensors based on CILEs and IL/composite-modified macrodisk electrodes. Subsequently, recent developments and major strategies for enhancing sensing performance are discussed. Key challenges and opportunities of IL-based biosensors to further development and use are considered. Emphasis is given to direct electron-transfer reaction and electrocatalysis of hemeproteins and enzyme-modified composite electrodes.
Rapid fabrication of homogeneously distributed hyper-branched gold nanostructured electrode based electrochemical immunosensor for detection of protein biomarkers
Publisher: Elsevier BV
Date: 2021
Enabling Rapid and Specific Surface-Enhanced Raman Scattering Immunoassay Using Nanoscaled Surface Shear Forces
Publisher: American Chemical Society (ACS)
Date: 22-05-2015
Abstract: A rapid and simple approach is presented to address two critical issues of surface-enhanced Raman scattering (SERS)-based immunoassay such as removal/avoiding nonspecific adsorption and reducing assay time. The approach demonstrated involves rationally designed fluorophore-integrated gold/silver nanoshells as SERS nanotags and utilizes alternative current electrohydrodynamic (ac-EHD)-induced nanoscaled surface shear forces to enhance the capture kinetics. The assay performance was validated in comparison with hydrodynamic flow and conventional immunoassay-based devices. These nanoscaled physical forces acting within nanometer distances from the electrode surface enabled rapid (40 min), sensitive (10 fg/mL), and highly specific detection of human epidermal growth factor receptor 2 in breast cancer patient s les. We believe this approach presents potential for the development of rapid and sensitive SERS immunoassays for routine clinical diagnosis.
Detection of the SARS-CoV-2 humanized antibody with paper-based ELISA
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0AN01609H
Abstract: This work reports the development of a rapid, simple and inexpensive colorimetric paper-based assay for the detection of the severe acute respiratory symptom coronavirus 2 (SARS-CoV-2) humanized antibody.
Detection of aberrant protein phosphorylation in cancer using direct gold-protein affinity interactions
Publisher: Elsevier BV
Date: 05-2017
DOI: 10.1016/J.BIOS.2016.12.012
Abstract: Protein phosphorylation is one of the most prominent post-translational mechanisms for protein regulation, which is frequently impaired in cancer. Through the covalent addition of phosphate groups to certain amino-acids, the interactions of former residues with nearby amino-acids are drastically altered, resulting in major changes of protein conformation that impacts its biological function. Herein, we report that these conformational changes can also disturb the protein's ability to interact with and adsorb onto bare gold surfaces. We exploited this feature to develop a simple electrochemical method for detecting the aberrant phosphorylation of EGFR protein in several lung cancer cell lines. This method, which required as low as 10ng/µL (i.e., 50ng) of purified EGFR protein, also enabled monitoring cell sensitivity to tyrosine kinase inhibitors (TKI) - a common drug used for restoring the function of aberrantly phosphorylated proteins in lung cancer. The reported strategy based on direct gold-protein affinity interactions avoids the conventional paradigm of requiring a phospho-specific antibody for detection and could be a potential alternative of widely used mass spectrometry.
Bioengineered Polymer Nanobeads for Isolation and Electrochemical Detection of Cancer Biomarkers
Publisher: American Chemical Society (ACS)
Date: 29-06-2021
Quantification of gene-specific DNA methylation in oesophageal cancer via electrochemistry
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.ACA.2017.04.034
Abstract: Development of simple and inexpensive method for the analysis of gene-specific DNA methylation is important for the diagnosis and prognosis of patients with cancer. Herein, we report a relatively simple and inexpensive electrochemical method for the sensitive and selective detection of gene-specific DNA methylation in oesophageal cancer. The underlying principle of the method relies on the affinity interaction between DNA bases and unmodified gold electrode. Since the affinity trend of DNA bases towards the gold surface follows as adenine (A) > cytosine (C) > guanine (G)> thymine (T), a relatively larger amount of bisulfite-treated adenine-enriched unmethylated DNA adsorbs on the screen-printed gold electrodes (SPE-Au) in comparison to the guanine-enriched methylated s le. The methylation levels were (i.e., different level of surface attached DNA molecules due to the base dependent differential adsorption pattern) quantified by measuring saturated amount of charge-compensating [Ru(NH
Autoantibodies as diagnostic and prognostic cancer biomarker: Detection techniques and approaches
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.BIOS.2019.111315
Abstract: Autoantibodies produced by the patients' own immune systems in response to foreign substances are emerging as an attractive biomarker for early detection of cancer. These serum immunobiomarkers are produced in large quantities despite the presence of very less amount of the corresponding antigens, and thus presenting themselves as a novel class of stable and minimally invasive disease biomarkers especially for cancer diagnosis. Although a plethora of research, including conventional molecular biology-based as well as cutting-edge optical and electrochemical strategies (biosensor), have been conducted to detect autoantibodies, most of these strategies are yet to be readily applicable in the off-laboratory settings at clinics. Herein, we detail the biogenesis, diagnostic, prognostic and therapeutic potential of autoantibodies as cancer biomarkers. With the particular emphasis on cutting-edge advances in electrochemistry, optical (surface plasmon resonance) and microfluidics techniques, this review entrusts the unmet needs and challenges of autoantibody detection approaches and provides a future perspective of the presented strategies. We believe this review can potentially guide the researchers towards the development of robust, reliable and sensitive detection strategies for tumor-associated autoantibodies and translation of these biomarkers to real clinical settings for diagnosis and prognosis of cancer.
Challenges and perspectives in the development of paper-based lateral flow assays
Publisher: Springer Science and Business Media LLC
Date: 02-2020
Nano-yeast–scFv probes on screen-printed gold electrodes for detection of Entamoeba histolytica antigens in a biological matrix
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.BIOS.2013.12.043
Abstract: The time and costs associated with monoclonal antibody production limit the potential for portable diagnostic devices to penetrate the market. Replacing the antibody with a low-cost alternate affinity reagent would reduce the costs of diagnostic development and use, and lead to new portable diagnostic devices towards many diseases. Herein, we present low-cost affinity reagents, nano-yeast-scFv, on commercially available, inexpensive, and portable screen-printed electrodes for the label-free electrochemical detection of Entamoeba histolytica cyst antigens. The biosensor was able to detect antigen at concentrations down to 10 pg mL(-1) in buffer with an inter-assay reproducibility of (% RSD, n=3) 4.1%. The applicability of two differently engineered nano-yeast-scFv to each specifically detect their cognant E. histolytica cyst antigens was demonstrated in a biological matrix derived from human stool. Because of the simple, inexpensive, and sensitive nature of this methodology, it may offer a low-cost alternative to immunosensors based on antibody-target recognition.
An Electrochemical Method for the Detection of Disease-Specific Exosomes
Publisher: Wiley
Date: 30-08-2017
Petroleum Hydrocarbons-Contaminated Soils: Remediation Approaches
Publisher: Springer International Publishing
Date: 2016
Trace Analysis of DNA: Preconcentration, Separation, and Electrochemical Detection in Microchip Electrophoresis Using Au Nanoparticles
Publisher: American Chemical Society (ACS)
Date: 12-04-2007
DOI: 10.1021/AC0701177
Abstract: We have developed a simple and sensitive on-chip preconcentration, separation, and electrochemical detection (ED) method for trace analysis of DNA. The microchip comprised of three parallel channels: the first two are for the field- lified s le stacking and subsequent field- lified s led injection steps, while the third one is for the microchip gel electrophoresis (MGE) with ED (MGE-ED). To improve preconcentration and separation performances of the method, the stacking and separation buffers containing the hydroxypropyl cellulose (HPC) matrix were modified with gold nanoparticles (AuNPs). The formation of AuNPs and HPC/AuNP-modified buffers were characterized by UV-visible spectroscopy and TEM experiments. The conducting polymer-modified electrode was also modified with AuNPs to enhance detection performances of the electrode. The conducting polymer/AuNP layers act as electrocatalysts for the direct detection of DNA based on their oxidation in a solution phase. The total sensitivity was improved by approximately 25 000-fold when compared with a conventional MGE-ED analysis. The calibration plots were linear (r2 = 0.9993) within the range of 0.003-1.0 pg/microL for a 20-bp DNA s le. The sensitivity was 0.20 nA/(fg/microL), with a detection limit of 5.7 amol in a 50-microL s le, based on S/N = 3. The applicability of the method for the analysis of 13 fragments present in a 100-bp DNA ladder was successfully demonstrated.
eLCR: electrochemical detection of single DNA base changes via Ligase Chain Reaction
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC35841G
Abstract: Simple, inexpensive and wide-scaled analysis of single DNA base changes ('point mutations' which include SNP's, somatic mutations and epigenetic changes) is one of the holy grail's of point-of-care diagnostics. Herein, we present eLCR: a simple methodology that fuses Ligase Chain Reaction (LCR) with electrochemical detection based on DNA-mediated charge transport. LCR generates long and short "knife" motifs representing the presence or absence of single DNA base changes, which are then detected electrochemically by either methylene blue intercalation or horseradish peroxidase labelling.
Wicking in Paper Strips under Consideration of Liquid Absorption Capacity
Publisher: MDPI AG
Date: 06-08-2020
DOI: 10.3390/CHEMOSENSORS8030065
Abstract: Paper-based microfluidic devices have the potential of being a low-cost platform for diagnostic devices. Electrical circuit analogy (ECA) model has been used to model the wicking process in paper-based microfluidic devices. However, material characteristics such as absorption capacity cannot be included in the previous ECA models. This paper proposes a new model to describe the wicking process with liquid absorption in a paper strip. We observed that the fluid continues to flow in a paper strip, even after the fluid reservoir has been removed. This phenomenon is caused by the ability of the paper to store liquid in its matrix. The model presented in this paper is derived from the analogy to the current response of an electric circuit with a capacitance. All coefficients in the model are fitted with data of capillary rise experiments and compared with direct measurement of the absorption capacity. The theoretical data of the model agrees well with experimental data and the conventional Washburn model. Considering liquid absorption capacity as a capacitance helps to explain the relationship between material characteristics and the wicking mechanism.
Exosomal microRNAs array sensor with a bioconjugate composed of p53 protein and hydrazine for the specific lung cancer detection
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.BIOS.2022.114149
Abstract: For the early diagnosis of lung cancer, a novel strategy to detect microRNAs encapsulated in exosomes with immunomagnetic isolation was demonstrated for the selective extraction of exo-miRNAs from patient serum. Here, miRNA was captured from lysed exosomes in specially designed capture probe modified magnetic beads, followed by T4 DNA polymerase-mediated in situ formation of chimeric 5'-miRNA-DNA-3' (Target). The poly-(2,2':5',2''-terthiophene-3'-(p-benzoic acid)) (pTBA)-modified electrode harbors Probe-1 DNA that hybridizes to the 5' end of the chimera, followed by hybridization of Probe-2 DNA to the 3' end of the chimera, resulting in the formation of a 20-nucleotide-long dsDNA consensus sequence for p53 protein binding. A bioconjugate composed of p53 and hydrazine assembled on AuNPs (p53-AuNPs-Hyd) recruits the p53 protein to recognize a specific sequence, forming the final sensor probe (pTBA-Probe-1:Target/Probe-2:bioconjugate), where hydrazine functions as an electrocatalyst to generate erometric signal from the reduction of H
Hard-templated preparation of mesoporous cobalt phosphide as an oxygen evolution electrocatalyst
Publisher: Elsevier BV
Date: 07-2019
Hypoxia-induced small extracellular vesicle proteins regulate proinflammatory cytokines and systemic blood pressure in pregnant rats.
Publisher: Portland Press Ltd.
Date: 03-2020
DOI: 10.1042/CS20191155
Abstract: Small extracellular vesicles (sEVs) released from the extravillous trophoblast (EVT) are known to regulate uterine spiral artery remodeling during early pregnancy. The bioactivity and release of these sEVs differ under differing oxygen tensions and in aberrant pregnancy conditions. Whether the placental cell-derived sEVs released from the hypoxic placenta contribute to the pathophysiology of preecl sia is not known. We hypothesize that, in response to low oxygen tension, the EVT packages a specific set of proteins in sEVs and that these released sEVs interact with endothelial cells to induce inflammation and increase maternal systemic blood pressure. Using a quantitative MS/MS approach, we identified 507 differentially abundant proteins within sEVs isolated from HTR-8/SVneo cells (a commonly used EVT model) cultured at 1% (hypoxia) compared with 8% (normoxia) oxygen. Among these differentially abundant proteins, 206 were up-regulated and 301 were down-regulated (P & 0.05), and they were mainly implicated in inflammation-related pathways. In vitro incubation of hypoxic sEVs with endothelial cells, significantly increased (P & 0.05) the release of GM-CSF, IL-6, IL-8, and VEGF, when compared with control (i.e. cells without sEVs) and normoxic sEVs. In vivo injection of hypoxic sEVs into pregnant rats significantly increased (P & 0.05) mean arterial pressure with increases in systolic and diastolic blood pressures. We propose that oxygen tension regulates the release and bioactivity of sEVs from EVT and that these sEVs regulate inflammation and maternal systemic blood pressure. This novel oxygen-responsive, sEVs signaling pathway, therefore, may contribute to the physiopathology of preecl sia.
Magnetophoretic separation of diamagnetic particles through parallel ferrofluid streams
Publisher: Elsevier BV
Date: 12-2018
“Drill and fill” lithography for controlled fabrication of 3D platinum electrodes
Publisher: Elsevier BV
Date: 08-2013
Outstanding Reviewers for Analyst in 2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1AN90033A
Abstract: We would like to take this opportunity to highlight the Outstanding Reviewers for Analyst in 2020, as selected by the editorial team for their significant contribution to the journal.
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