ORCID Profile
0000-0003-2097-063X
Current Organisation
University of New South Wales
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Publisher: American Chemical Society (ACS)
Date: 17-07-2013
DOI: 10.1021/JF401464R
Abstract: Low-molecular-weight organic molecules, such as coumarins and stilbenes, are used commercially as fluorescent whitening agents (FWAs) to mask photoyellowing and to brighten colors in fabrics. FWAs achieve this by radiating extra blue light, thus changing the hue and also adding to the brightness. However, organic FWAs can rapidly photodegrade in the presence of ultraviolet (UV) radiation, exacerbating the yellowing process through a reaction involving singlet oxygen species. Inorganic nanoparticles, on the other hand, can provide a similar brightening effect with the added advantage of photostability. We report a targeted approach in designing new inorganic silicon- and germanium-based nanoparticles, functionalized with hydrophilic (amine) surface terminations as novel inorganic FWAs. When applied on wool, by incorporation in a sol-gel Si matrix, the inorganic FWAs improved brightness properties, demonstrated enhanced photostability toward UV radiation, especially the germanium nanoparticles, and also generated considerably lower levels of reactive oxygen species compared to a commercial stilbene-based organic FWA, Uvitex NFW.
Publisher: SPIE
Date: 08-02-2007
DOI: 10.1117/12.699772
Publisher: American Chemical Society (ACS)
Date: 07-06-2011
DOI: 10.1021/CG200660Y
Publisher: American Chemical Society (ACS)
Date: 12-10-2023
Publisher: Elsevier BV
Date: 04-2013
Publisher: Informa UK Limited
Date: 03-2013
Publisher: American Chemical Society (ACS)
Date: 05-10-2012
DOI: 10.1021/JA302964E
Abstract: A century ago Ostwald described the "Rule of Stages" after deducing that crystal formation must occur through a series of intermediate crystallographic phases prior to formation of the final thermodynamically stable structure. Direct evidence of the Rule of Stages is lacking, and the theory has not been implemented to allow isolation of a selected structural phase. Here we report the role of Ostwald's Rule of Stages in the growth of CdSe quantum dots (QDs) from molecular precursors in the presence of hexadecylamine. It is observed that, by controlling the rate of growth through the reaction stoichiometry and therefore the probability of ion-packing errors in the growing QD, the initially formed zinc blende (ZB) critical nuclei representing the kinetic phase can be maintained at sizes >14 nm in diameter without phase transformation to the thermodynamic wurtzite (WZ) structure. An intermediate pseudo-ZB structure is observed to appear at intermediate reaction conditions, as predicted by Ostwald. The ZB and pseudo-ZB structures convert to the WZ lattice above a critical melting temperature. This study validates Ostwald's Rule of Stages and provides a phase diagram for growth of CdSe QDs exhibiting a specific crystallographic motif.
Publisher: Springer Science and Business Media LLC
Date: 27-08-2018
DOI: 10.1038/S41565-018-0232-X
Abstract: There is intense interest in quantifying the levels of microRNA because of its importance as a blood-borne biomarker. The challenge has been to develop methods that can monitor microRNA expression both over broad concentration ranges and in ultralow amounts directly in a patient's blood. Here, we show that, through electric-field-induced reconfiguration of a network of gold-coated magnetic nanoparticles modified by probe DNA (DNA-Au@MNPs), it is possible to create a highly sensitive sensor for direct analysis of nucleic acids in s les as complex as whole blood. The sensor is the first to be able to detect concentrations of microRNA from 10 aM to 1 nM in unprocessed blood s les. It can distinguish small variations in microRNA concentrations in blood s les of mice with growing tumours. The ultrasensitive and direct detection of microRNA using an electrically reconfigurable DNA-Au@MNPs network makes the reported device a promising tool for cancer diagnostics.
Publisher: Wiley
Date: 31-05-2022
Abstract: The use of nanoparticles and nanostructured electrodes are abundant in electrocatalysis. These nanometric systems contain elements of nanoconfinement in different degrees, depending on the geometry, which can have a much greater effect on the activity and selectivity than often considered. In this Review, we firstly identify the systems containing different degrees of nanoconfinement and how they can affect the activity and selectivity of electrocatalytic reactions. Then we follow with a fundamental understanding of how electrochemistry and electrocatalysis are affected by nanoconfinement, which is beginning to be uncovered, thanks to the development of new, atomically precise manufacturing and fabrication techniques as well as advances in theoretical modeling. The aim of this Review is to help us look beyond using nanostructuring as just a way to increase surface area, but also as a way to break the scaling relations imposed on electrocatalysis by thermodynamics.
Publisher: American Chemical Society (ACS)
Date: 23-09-2005
DOI: 10.1021/JP054565Z
Abstract: Monodisperse 1-2 nm silicon nanocrystals are synthesized in reverse micelles and have their surfaces capped with either allylamine or 1-heptene to produce either hydrophilic or hydrophobic silicon nanocrystals. Optical characterization (absorption, PL, and time-resolved PL) is performed on colloidal solutions with the two types of surface-capped silicon nanocrystals with identical size distributions. Direct evidence is obtained for the modification of the optical properties of silicon nanocrystals by the surface-capping molecule. The two different surface-capped silicon nanocrystals show remarkably different optical properties.
Publisher: Research Square Platform LLC
Date: 09-02-2022
DOI: 10.21203/RS.3.RS-1274090/V1
Abstract: Carrier loss mechanisms at microscopic regions is imperative for high-performance polycrystalline inorganic thin-film solar cells. Despite the progress on Kesterite, a promising environmental-benign and earth-abundant thin-film photovoltaic material, the microscopic carrier loss mechanisms and their impact on device performance remain unknown. Herein, we unveil these mechanisms in state-of-the-art Cu 2 ZnSnSe 4 (CZTSe) solar cells using a framework that links microscopic-structural and optoelectronic characterizations with three-dimensional device simulations. The results indicate the CZTSe films have an encouraging intragrain minority carrier lifetime of ns, a marginal radiative recombination loss through sub-band recombination and electrostatic potential fluctuation, whilst a large effective grain boundary recombination velocity of around 10 4 cm s -1 and a low net carrier density of ~1×10 15 cm -3 . We identify that severe grain boundary recombination and low net carrier density are the current limiting factors of device performance. The established framework can greatly advance the research of kesterite and other emerging photovoltaic materials.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0SC05489E
Abstract: A light addressable single-cell impedance technique for cell adhesion monitoring and measurement of a cell's drug response based on electrochemical noise is introduced.
Publisher: Walter de Gruyter GmbH
Date: 12-2009
Abstract: We describe here the synthesis and characterization of silicon nanocrystals prepared by using microemulsion technique which involved the formation of inverse micelles. Colloidal systems employing TOAB as the surfactant molecules were used to synthesise nanosized silicon nanocrystals. The initial reaction of silicon tetrachloride, SiCl 4 with a strong reducing agent, NaBH 4 produced Si nanocrystals with hydrogen terminated surfaces. The surfaces of the nanocrystals were then capped with 1-heptene which protected the silicon nanocrystals from oxidation. The resultant surface passivated silicon nanocrystals suspended in organic solvent were characterized by Fourier transform infrared spectroscopy, photoluminescence spectroscopy and high resolution transmission electron microscopy. This study provided direct evidence of ageing, stability of different surface passivation and the quantum confinement effect in nanosized silicon nanocrystals.
Publisher: Elsevier BV
Date: 09-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2009
DOI: 10.1039/B902474C
Publisher: American Chemical Society (ACS)
Date: 22-12-2010
DOI: 10.1021/NN901277K
Abstract: Palladium is widely used as a catalyst in pharmaceutical and chemical syntheses as well as in the reduction of harmful exhaust emissions. Therefore, the development of high performance palladium catalysts is an area of major concern. In this paper, we present the synthesis of highly branched palladium nanostructures in a simple solution phase reaction at room temperature. By varying the nature of the organic stabilizer system we demonstrate control over the reaction kinetics and hence the shape of the nanostructures. Investigations into the structural evolution of the nanostructures show that they form from multiply twinned face centered cubic (fcc) nanoparticle nuclei. Reaction kinetics then determine the resulting shape where ultrafast growth is shown to lead to the highly branched nanostructures. These results will contribute greatly to the understanding of complex nanoparticle growth from all fcc metals. The nanostructures then show excellent catalytic activity for the hydrogenation of nitrobenzene to aniline.
Publisher: American Chemical Society (ACS)
Date: 07-06-2017
DOI: 10.1021/ACS.LANGMUIR.7B01028
Abstract: The role surface capping molecules play in dictating the optical properties of semiconductor nanocrystals (NCs) is becoming increasingly evident. In this paper the role of surface capping molecule polarity on the optical properties of germanium NCs (Ge NCs) is explored. Capping molecules are split into two groups: nonpolar and polar. The NCs are fully characterized structurally and optically to establish the link between observed optical properties and surface capping molecules. Ge NC optical properties altered by surface capping molecule polarity include emission maximum, emission lifetime, quantum yield, and Stokes shift. For Ge NCs, this work also allows rational tuning of their optical properties through changes to surface capping molecule polarity, leading to improvements in emerging Ge based bioimaging and optoelectronic devices.
Publisher: American Chemical Society (ACS)
Date: 14-04-2015
DOI: 10.1021/ACS.JPCLETT.5B00589
Abstract: A new synthetic method was developed to produce a range of transition-metal (Mn, Ni, and Cu) doped silicon nanocrystals (Si NCs). The synthesis produces monodisperse undoped and doped Si NCs with comparable average sizes as shown by transmission electron microscopy (TEM). Dopant composition was confirmed by EDX (energy dispersive X-ray spectroscopy). The optical properties of undoped and doped were compared and contrasted using absorption (steady-state and transient) and photoluminescence spectroscopy. Doped Si NCs demonstrated unique dopant-dependent optical properties compared to undoped Si NCs such as enhanced subgap absorption, and 40 nm shifts in the emission. Transient absorption (TA) measurements showed that photoexcitations in doped Si NCs relaxed via dopant states not present in undoped Si NCs.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1CS00707F
Abstract: Targeted drug delivery in cancer typically focuses on maximising the endocytosis of drugs into the diseased cells. However, there has been less focus on exploiting the differences in the endocytosis pathways of cancer cells
Publisher: Wiley
Date: 13-07-2020
Publisher: American Chemical Society (ACS)
Date: 09-12-2020
Publisher: Wiley
Date: 30-09-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC41751D
Abstract: Herein we report the rational design of new phosphopeptides for control of nucleation, growth and aggregation of water-soluble, superparamagnetic iron-iron oxide core-shell nanoparticles. The use of the designed peptides enables a one-pot synthesis that avoids utilizing unstable or toxic iron precursors, organic solvents, and the need for exchange of capping agent after synthesis of the NPs.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9CC07046J
Abstract: AuNP easily synthesised inside bulk hydrogel spheres stable and catalytically active, even in high ionic strength environments.
Publisher: AIP Publishing
Date: 18-12-2000
DOI: 10.1063/1.1332407
Abstract: Very short nanofibers containing only a few nanobells have been produced from nitrogen-doped carbon nanotubes by two methods, H2 plasma treatment, followed by grinding and oxidation with acidified potassium permanganate. The length of these short nanofibers can be controlled to give a wide range of sizes. The shortest nanofibers are composed of only a single nanobell with dimensions of ∼15 nm in diameter and length. High-resolution transmission electron microscope images reveal that their structures are closed at one end and open at the other. The formation mechanism of these short nanofibers and in idual nanobells is discussed along with their potential for interesting nanotube-end physics and chemistry.
Publisher: SPIE
Date: 22-02-2017
DOI: 10.1117/12.2249592
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8NR03341B
Abstract: Pd–Ru nanoparticles with thin shells and a stable core are shown to improve stability in oxygen evolution reaction catalysis while retaining high activity.
Publisher: Wiley
Date: 03-04-2019
Abstract: An original wireless stimulator for peripheral nerves based on a metal loop (diameter ≈1 mm) that is powered by a transcranial magnetic stimulator (TMS) and does not require circuitry components is reported. The loop can be integrated in a chitosan scaffold that functions as a graft when applied onto transected nerves (graft‐antenna). The graft‐antenna is bonded to rat sciatic nerves by a laser without sutures it does not migrate after implantation and is able to trigger steady compound muscle action potentials for 12 weeks (CMAP ≈1.3 mV). Eight weeks postoperatively, axon regeneration is facilitated in transected nerves that are repaired with the graft‐antenna and stimulated by the TMS for 1 h per week. The graft‐antenna is an innovative and minimally‐invasive device that functions concurrently as a wireless stimulator and adhesive scaffold for nerve repair.
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.BIOS.2022.114126
Abstract: Alterations in DNA methylation, a stable epigenetic marker, are important components in the development of cancer. It is vital to develop diagnostic systems with the ability to rapidly quantify DNA methylation with high sensitivity and selectivity. However, the analysis of DNA methylation must address two main challenges: (i) ultralow abundance and (ii) differentiating methylated cytosine from normal cytosine on target DNA sequence in the presence of an overwhelming background of circulating cell-free DNA. Here we report the development of an ultrasensitive and highly-selective electrochemical biosensor for the rapid detection of DNA methylation in blood. The sensing of DNA methylation involves the hybridization on a network of probe DNA modified gold-coated magnetic nanoparticles (DNA-Au@MNPs) complementary to target DNA, and subsequently enzymatic cleavage to differentiate methylated DNA strands from corresponding unmethylated DNA strands. The biosensor presents a dynamic range from 2 aM to 20 nM for 110 nucleotide DNA sequences containing a single-site methylation with the lowest detected concentration of 2 aM. This DNA-Au@MNPs based sensor provides a promising method to achieve 35 min response time and minimally invasive diagnosis of ovarian cancer.
Publisher: Elsevier BV
Date: 02-2016
Publisher: Wiley
Date: 12-09-2019
Publisher: American Chemical Society (ACS)
Date: 10-12-2009
DOI: 10.1021/CM9030599
Publisher: Wiley
Date: 04-09-2013
Publisher: IOP Publishing
Date: 03-09-2008
DOI: 10.1088/0957-4484/19/41/415102
Abstract: Semiconductor quantum dots (QDs) hold some advantages over conventional organic fluorescent dyes. Due to these advantages, they are becoming increasingly popular in the field of bioimaging. However, recent work suggests that cadmium based QDs affect cellular activity. As a substitute for cadmium based QDs, we have developed photoluminescent stable silicon quantum dots (Si-QDs) with a passive-oxidation technique. Si-QDs (size: 6.5 ± 1.5 nm) emit green light, and they have been used as biological labels for living cell imaging. In order to determine the minimum concentration for cytotoxicity, we investigated the response of HeLa cells. We have shown that the toxicity of Si-QDs was not observed at 112 µg ml(-1) and that Si-QDs were less toxic than CdSe-QDs at high concentration in mitochondrial assays and with lactate dehydrogenase (LDH) assays. Especially under UV exposure, Si-QDs were more than ten times safer than CdSe-QDs. We suggest that one mechanism for the cytotoxicity is that Si-QDs can generate oxygen radicals and these radicals are associated with membrane damages. This work has demonstrated the suitability of Si-QDs for bioimaging in lower concentration, and their cytotoxicity and one toxicity mechanism at high concentration.
Publisher: Research Square Platform LLC
Date: 30-07-2020
DOI: 10.21203/RS.3.RS-47321/V1
Abstract: All-inorganic CsPbI3 perovskite quantum dots (QDs) have received intense research interest for photovoltaic applications because of the recently demonstrated higher power conversion efficiency compared to solar cells using other QD materials. These QD devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. In this work, through developing a hybrid interfacial architecture consisting of CsPbI3 QD/PCBM heterojunctions, we report the formation of an energy cascade for efficient charge transfer at both QD heterointerfaces and QD/electron transport layer interfaces. The ch ion CsPbI3 QD solar cell has a best power conversion efficiency of 15.1%, which is among the highest report to date. Building on this strategy, we demonstrate the very first perovskite QD flexible solar cell with a record efficiency of 12.3%. A detailed morphological characterization reveals that the perovskite QD film can better retain structure integrity than perovskite bulk thin-film under external mechanical stress. This work is the first to demonstrate higher mechanical endurance of QD film compared to bulk thin-film, and highlights the importance of further research on high‐performance and flexible optoelectronic devices using solution-processed QDs.
Publisher: American Chemical Society (ACS)
Date: 24-03-2009
DOI: 10.1021/CM900110H
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CY00720A
Abstract: Monodisperse faceted icosahedral Au–Pd core–shell nanocrystals of small size ( nm) supported on Vulcan XC-72 (Au–Pd/C) are employed in electroreforming for the cogeneration of hydrogen and valuable chemicals.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CC02959A
Abstract: The spatial resolution of silicon photoelectrochemistry is improved to 500 nm by using amorphous silicon, 60 times improvement as compared to crystalline silicon.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1SC01044A
Abstract: This study introduces a new electrochemical sensing strategy for the rapid detection of circulating tumor DNA (ctDNA) from whole blood in combination with a network of DNA-Au@MNPs with high sensitivity and excellent selectivity.
Publisher: Springer Science and Business Media LLC
Date: 27-12-2013
Publisher: American Chemical Society (ACS)
Date: 04-2021
Publisher: American Chemical Society (ACS)
Date: 03-01-2023
Publisher: IEEE
Date: 2006
Publisher: Informa UK Limited
Date: 02-09-2018
DOI: 10.1080/17425247.2018.1517748
Abstract: Interest in mesoporous silica nanoparticles for drug delivery has resulted in a good understanding of the impact of size and surface chemistry of these nanoparticles on their performance as drug carriers. Shape has emerged as an additional factor that can have a significant effect on delivery efficacy. Rod-shaped mesoporous silica nanoparticles show improvements in drug delivery relative to spherical mesoporous silica nanoparticles. This review summarises the synthesis methods for producing rod-shaped mesoporous silica nanoparticles for use in nanomedicine. The second part covers recent progress of mesoporous silica nanorods by comparing the impact of sphere and rod-shape on drug delivery efficiency. As hollow mesoporous silica nanorods are capable of higher drug loads than most other drug delivery vehicles, such particles will reduce the amount of mesoporous silica in the body for efficient therapy. However, the importance of nanoparticle shape on drug delivery efficiency is not well understood for mesoporous silica. Studies that visualize and quantify the uptake pathway of mesoporous silica nanorods in specific cell types and compare the cellular uptake to the well-studied nanospheres should be the focus of research to better understand the role of shape in uptake.
Publisher: American Chemical Society (ACS)
Date: 12-12-2019
Publisher: Wiley
Date: 20-01-2013
Abstract: Branched metal nanostructures are of great technological importance because of their unique size- and shape-dependent properties. A kinetically controlled synthesis that uses polymorphism to produce branched nickel nanoparticles is presented. These nanoparticles consist of a face-centred cubic (fcc) core and extended arms of alternating fcc and hexagonal close-packed (hcp) nickel phases.
Publisher: Elsevier BV
Date: 05-2012
Publisher: Wiley
Date: 10-02-2011
Publisher: Elsevier BV
Date: 09-2016
Publisher: American Chemical Society (ACS)
Date: 31-05-2018
Abstract: LaAlO
Publisher: American Chemical Society (ACS)
Date: 30-08-2021
DOI: 10.26434/CHEMRXIV-2021-2W10H
Abstract: Developing alternatives to platinum-based electrocatalysts for the hydrogen evolution reaction (HER) is an important challenge for realizing the green transition. This is especially the case for alkaline conditions where Pt-based catalysts have very poor stability. Here, we demonstrate new solvothermal synthesis methods with facile allotropism control for selectively obtaining hexagonal-close-packed (hcp) and face-centered cubic (fcc) ruthenium nanoparticles. Both s les are highly active HER catalysts in alkaline conditions outperforming commercial Pt/C. However, the s les show markedly different stabilities. The hcp s le shows exceptional stability for 12 hours constant operation at 10 mA/cm2 with an overpotential that only increases 6 mV whereas the fcc s le increases 50 mV and the commercial Pt/C more than 350 mV. Thus, this study underlines the importance of controlling the crystal structure of nanoparticle electrocatalysts and shows the potential of using Ru as an alternative to Pt in alkaline conditions.
Publisher: Wiley
Date: 12-10-2020
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.CARBPOL.2017.02.081
Abstract: Phenoxodiol is an isoflavone analogue that possesses potent anticancer properties. However, the poor water solubility of phenoxodiol limits its overall efficacy as an anticancer agent. To overcome this, β-cyclodextrin was used to encapsulate phenoxodiol. The phenoxodiol-β-cyclodextrin complex was prepared via a modified co-evaporation method and characterized by
Publisher: Wiley
Date: 12-12-2013
Publisher: Springer Science and Business Media LLC
Date: 18-10-2008
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9AN01519A
Abstract: A glucose meter-based immunosensing platform that allows the quantification of procalcitonin in whole blood s les at clinically-relevant concentrations.
Publisher: Elsevier BV
Date: 10-2017
Publisher: American Chemical Society (ACS)
Date: 24-10-2019
Abstract: A multilayered nanocomposite designed for biomedical applications based on (TiAlSiY)N/CrN coating implanted by heavy Au
Publisher: American Chemical Society (ACS)
Date: 10-12-2009
DOI: 10.1021/JA906501V
Abstract: This Article describes research on chemical reactions on molecules attached to the surface of silicon quantum dots that have been performed to produce quantum dots with reactive surface functionalities such as diols and epoxides. Characterization of the surface reactions includes NMR and FT-IR studies, and the quantum dots were characterized by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Cytotoxicity and cell viability assay conducted on silicon dots capped with polar molecules indicated low toxicity with quantum dots with more reactive functionalities found to be more toxic. The silicon quantum dots photoluminesce and have been used as a blue chromophore for the biological imaging of cells.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1CC05165B
Abstract: A new type of gold-coated magnetic nanoparticle with strongly magnetic zero-valent iron core-iron oxide shell were synthesized. The small size of the magnetic cores and the zero-valent iron ensured superparamagnetic behaviour and high saturation magnetization of the overall nanoparticles. The nanoparticles showed stability against magnetic aggregation and good colloidal stability, which is important for many biomedical applications.
Publisher: Springer Science and Business Media LLC
Date: 23-10-2023
Publisher: Wiley
Date: 30-09-2020
Abstract: Single molecule measurements are revolutionizing the understanding of the stochastics of behavior of single molecules. There is a common theme referred to as a near-field approach, in how many single molecule measurements are being performed in assays. The term near field is used because the measurement volume is typically very small such that a single molecule, or a single molecule binding pair, within that volume is of an appreciable concentration. The next development in detection will be performing many single molecule measurements at one time such that single molecule measurements can be used as the basis for quantitative analysis. There have already been some notable developments in this direction. Again, all have a common theme in that nanoparticles are used to create many near-field volumes that can be measured simultaneously. Herein, the coupled developments in nanoparticles and measurement strategies that allow nanoparticles to be the backbone of the next generation of sensing technologies are discussed.
Publisher: American Chemical Society (ACS)
Date: 28-01-2022
DOI: 10.1021/ACS.NANOLETT.1C03976
Abstract: Nanopore sensors have received significant interest for the detection of clinically important biomarkers with single-molecule resolution. These sensors typically operate by detecting changes in the ionic current through a nanopore due to the translocation of an analyte. Recently, there has been interest in developing optical readout strategies for nanopore sensors for quantitative analysis. This is because they can utilize wide-field microscopy to independently monitor many nanopores within a high-density array. This significantly increases the amount of statistics that can be obtained, thus enabling the analysis of analytes present at ultralow concentrations. Here, we review the use of optical nanopore sensing strategies for quantitative analysis. We discuss optical nanopore sensing assays that have been developed to detect clinically relevant biomarkers, the potential for multiplexing such measurements, and techniques to fabricate high density arrays of nanopores with a view toward the use of these devices for clinical applications.
Publisher: Springer Science and Business Media LLC
Date: 06-2016
DOI: 10.1038/AM.2016.73
Publisher: Begell House
Date: 2021
Publisher: Research Square Platform LLC
Date: 19-01-2021
DOI: 10.21203/RS.3.RS-132040/V1
Abstract: Single Pt atom catalysts on non-active carbon supports have been key targets for electrochemical reactions because the high exposure of active Pt leads to record-high activities. PtRu alloy catalysts are the most active for the methanol oxidation reaction (MOR) as the Ru atoms decrease CO poisoning of the active Pt. To combine the exceptional activity of single atom Pt catalysts with the benefits of an active Ru support we must overcome the synthetic challenge of forming single Pt atoms on noble metal nanoparticles. We have developed a concept to grow and spreads Pt islands on faceted Ru branched nanoparticles to make single Pt atom on Ru catalysts. By following the spreading process with in situ TEM, we show that the formation of single atoms is thermodynamically driven by the formation of strong Pt-Ru bonds and a lowering of surface area. The single Pt atom on Ru catalysts successfully limit CO poisoning during MOR to produce record current density and mass activity over time.
Publisher: American Chemical Society (ACS)
Date: 28-12-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1NR10458F
Abstract: This article describes the size control synthesis of silicon quantum dots with simple microemulsion techniques. The silicon nanocrystals are small enough to be in the strong confinement regime and photoluminesce in the blue region of the visible spectrum and the emission can be tuned by changing the nanocrystal size. The silicon quantum dots were capped with allylamine either a platinum catalyst or UV-radiation. An extensive purification protocol is reported and assessed using (1)H NMR to produce ultra pure silicon quantum dots suitable for biological studies. The highly pure quantum dots were used in cellular uptake experiments and monitored using confocal microscopy. The results showed that the amine terminated silicon nanocrystals accumulated in lysosome but not in nuclei and could be used as bio-markers to monitor cancer cells over long timescales.
Publisher: Royal Society of Chemistry (RSC)
Date: 2002
DOI: 10.1039/B204774H
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8CC07889K
Abstract: A transparent electrode which is able to perform simultaneous photoswitchable electrochemistry and optical microscopy imaging.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1CS00972A
Abstract: Nanopores are promising sensing devices that can be used for the detection of analytes at the single molecule level. It is of importance to understand and model the current response of a nanopore sensor for improving the sensitivity of the sensor, a better interpretation of the behaviours of different analytes in confined nanoscale spaces, and quantitative analysis of the properties of the targets. The current response of a nanopore sensor, usually called a resistive pulse, results from the change in nanopore resistance when an analyte translocates through the nanopore. This article reviews the theoretical models used for the calculation of the resistance of the nanopore, and the corresponding change in nanopore resistance due to a translocation event. Models focus on the resistance of the pore cavity region and the access region of the nanopore. The influence of the sizes, shapes and surface charges of the translocating species and the nanopore, as well as the trajectory that the analyte follows are also discussed. This review aims to give a general guidance to the audience for understanding the current response of a nanopore sensor and the application of this class of sensor to a broad range of species with the theoretical models.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CC01661F
Abstract: Light is used to activate spatially and temporally resolved electrodeposition of multiple metals onto silicon.
Publisher: American Chemical Society (ACS)
Date: 06-04-2022
Abstract: Selective isolation of in idual target cells from a heterogeneous population is technically challenging however, the ability to retrieve single cells can have high significance in various aspects of biological research. Here, we present a new photoelectrochemical surface based on a transparent electrode that is compatible with high-resolution fluorescence microscopy for isolating in idual rare cells from complex biological s les. This is underpinned by two important factors: (i) careful design of the electrode by patterning discrete Au disks of micron dimension on amorphous silicon-indium tin oxide films and (ii) orthogonal surface chemistry, which modifies the patterned electrode with self-assembly layers of different functionalities, to selectively capture target cells on the Au disks and resist cell binding to the amorphous silicon surface. The co-stimulation of the surface using light from a microscope and an electric potential triggers the reductive desorption of the alkanethiol monolayer from the Au disks to release the single cells of interest from the illuminated regions only. Using circulating tumor cells as a model, we demonstrate the capture of cancer cells on an antibody-coated surface and selective release of single cancer cells with low expression of epithelial cell adhesion molecules.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 11-01-2023
Abstract: 3D interconnected structures can be made with molecular precision or with micrometer size. However, there is no strategy to synthesize 3D structures with dimensions on the scale of tens of nanometers, where many unique properties exist. Here, we bridge this gap by building up nanosized gold cores and nickel branches that are directly connected to create hierarchical nanostructures. The key to this approach is combining cubic crystal–structured cores with hexagonal crystal–structured branches in multiple steps. The dimensions and 3D morphology can be controlled by tuning at each synthetic step. These materials have high surface area, high conductivity, and surfaces that can be chemically modified, which are properties that make them ideal electrocatalyst supports. We illustrate the effectiveness of the 3D nanostructures as electrocatalyst supports by coating with nickel-iron oxyhydroxide to achieve high activity and stability for oxygen evolution reaction. This work introduces a synthetic concept to produce a new type of high-performing electrocatalyst support.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6NR06765D
Abstract: Controlling the structure of nanocrystals is an effective way to tune their properties and improve performance in a wide variety of applications. However, the atomic pathways for achieving this goal are difficult to identify and exercise, due to competing kinetic and thermodynamic influences during formation. In particular, an understanding of how symmetry, and symmetry breaking, determine nanocrystal morphology would significantly advance our ability to produce nanomaterials with prescribed functions. In this study we present results of a detailed computational study into the atomic structure of platinum nanoparticles at early growth stages of formation, as a function of temperature and atomic deposition rates. We investigate the impact of different types of crystalline seeds and characterize the emergent structures via simulated High Resolution Transmission Electron Microscopy (HRTEM) images. We find that the choice of initial seed is an important driver for symmetry breaking, due to a combination of atomic deposition and etching on different seed facets. A mix of low index facets causes the formation of important surface defects, in addition to the absorption/adsorption of single atoms, which can be correlated with different catalytic reactions as the process perpetuates. These findings provide new insights into nanocrystal shape-control mechanisms and suggest new opportunities for future design of this important class of nanomaterials.
Publisher: American Chemical Society (ACS)
Date: 25-11-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9CC08972A
Abstract: Zero valent iron core–iron oxide shell nanoparticles coated with a multi-phosphonate brush co-polymer are shown to be small and effective magnetic nanoparticle imaging tracers.
Publisher: MDPI AG
Date: 08-06-2022
DOI: 10.3390/NANO12121965
Abstract: This study investigated the fluorescence and biocompatibility of hydrophilic silicon quantum dots (SiQDs) that are doped with scandium (Sc-SiQDs), copper (Cu-SiQDs), and zinc (Zn-SiQDs), indicating their feasibility for the bioimaging of tear film. SiQDs were investigated for fluorescence emission by the in vitro imaging of artificial tears (TheraTears®), using an optical imaging system. A trypan blue exclusion test and MTT assay were used to evaluate the cytotoxicity of SiQDs to cultured human corneal epithelial cells. No difference was observed between the fluorescence emission of Sc-SiQDs and Cu-SiQDs at any concentration. On average, SiQDs showed stable fluorescence, while Sc-SiQDs and Cu-SiQDs showed brighter fluorescence emissions than Zn-SiQDs. Cu-SiQDs and Sc-SiQDs showed a broader safe concentration range than Zn-SiQDs. Cu-SiQDs and Zn-SiQDs tend to aggregate more substantially in TheraTears® than Sc-SiQDs. This study elucidates the feasibility of hydrophilic Sc-SiQDs in studying the tear film’s aqueous layer.
Publisher: American Chemical Society (ACS)
Date: 03-02-2014
DOI: 10.1021/LA404757Q
Abstract: The use of magnetic nanoparticles (MNPs) in real-world applications is often limited by the lack of stable solutions of monodisperse NPs in appropriate solvents. We report a facile one-pot ligand exchange reaction that is fast, efficient, and thorough for the synthesis of hydrophilic MNPs that are readily dispersed in polar organic and protic solvents (polarity index = 3.9-7.2) including alcohols, THF, DMF, and DMSO for years without precipitation. We emphasize the rational selection of small-molecule ligands such as 4-hydroxybenzoic acid (HBA), 3-(4-hydroxyphenyl)propionic acid (HPP), and gallic acid (GAL) that provide strong bonding with the MNP (FePt and FeOx) surfaces, hydrophilic termini to match the polarity of target solvents, and offer the potential for hydrogen-bonding interactions to facilitate incorporation into polymers and other media. Areal ligand densities (Σ) calculated based on the NP core size from transmission electron microscopy (TEM) images, and the inorganic fractions of NPs derived from thermogravimetric analysis (TGA) indicated a significant (2-4 times) increase in the ligand coverage after the exchange reactions. Fourier transform infrared spectrometry (FTIR) and (1)H nuclear magnetic resonance (NMR) studies also confirmed anchoring of carboxyl groups on NP surfaces. In addition, we demonstrate a facile one-step in situ synthesis of FePt NPs with aromatic ligands for better dispersibility in solvents of intermediate polarity (polarity index = 1.0-3.5) such as toluene, chlorobenzene, and dichloromethane. The creation of stable dispersions of NPs in solvents across the polarity spectrum opens up new applications and new processing widows for creating NP composites in a variety of host materials.
Publisher: American Chemical Society (ACS)
Date: 21-02-2007
DOI: 10.1021/JA067636W
Abstract: In this paper, we describe the synthesis and growth mechanism of highly monodispersed platinum nanocubes. The platinum nanocubes are synthesized by the decomposition of a platinum precursor in a hydrogen atmosphere. The morphology and size distribution of the platinum particles formed has been studied with HRTEM. By controlling the concentration of the platinum precursor, we demonstrate that at low concentration, it is possible to grow polydispersed nanocubes with {1,0,0} facets. Increasing the concentration of the precursor changes the growth mechanism, resulting in the formation of highly monodispersed platinum nanocubes. Highly monodispersed platinum nanocubes are formed in a two-step growth mechanism with initial growth of the {1,1,1} facets followed by secondary growth filling the {1,0,0} facets. The particle monodispersity facilitates the formation of long-range arrays of nanocubes.
Publisher: American Institute of Physics
Date: 2009
DOI: 10.1063/1.3203223
Publisher: IOP Publishing
Date: 02-06-2006
Publisher: Wiley
Date: 06-04-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7TA11257B
Abstract: Melamine is used to induce leaching of encapsulated metal impurities in MWCNTs. The leached impurities can be effectively removed or utilized as electrocatalytically active centres.
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B927225A
Publisher: SPIE
Date: 28-04-2005
DOI: 10.1117/12.601506
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.MSEC.2016.08.056
Abstract: Optical oxygen sensors have many promising qualities but rely on excitation by violet or blue wavelengths that suffer from high levels of scattering and absorption in biological tissues. Here we demonstrate an alternative method using 980nm near-infrared light to initially stimulate ceramic upconverting nanoparticles (UCNPs) contained within a novel form, electrospun core-shell fibers. The emission of the UCNPs excites a molecular optical oxygen sensor, the subsequent phosphorescent emission being dynamically quenched by the presence of molecular oxygen. The potential for use of such an energy transfer within electrospun fibers widely used in biological applications is promising. However, current knowledge of such 'handshake' interactions is limited. Fiber-based carriers enabling such optical conversions provide unique opportunities for biosensing as they recapitulate the topography of the extracellular matrix. This creates a wide array of potential theranostic, fiber-based applications in disease diagnosis/imaging, drug delivery and monitoring of therapeutic response. Using a fiber-based vehicle, we observed gaseous oxygen sensing capabilities and a linear Stern-Volmer response allowing highly accurate calibration. Configurational aspects were also studied to determine how to maximize the efficiency of this 'handshake' interaction.
Publisher: American Chemical Society (ACS)
Date: 23-04-2020
Publisher: Springer Science and Business Media LLC
Date: 12-08-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NR05156J
Abstract: General photoluminescence design rules for interstitial transition-metal-doped silicon nanocrystals are derived Zn shows excellent properties for medical imaging and plasmonic microwave excitation to exactly eliminate marked cells.
Publisher: American Chemical Society (ACS)
Date: 07-08-2013
DOI: 10.1021/JP405314G
Publisher: American Chemical Society (ACS)
Date: 21-11-2019
DOI: 10.1021/JACS.8B09397
Abstract: This Perspective focuses on the latest strategies and challenges for the development of bioanalytical sensors with sub-picomolar detection limits. Achieving sub-picomolar detection limits has three major challenges: (1) assay sensitivity, (2) response time, and (3) selectivity (including limiting background signals). Each of these challenges is discussed, along with how nanomaterials provide the solutions. One strategy to gain greater sensitivity involves confining the sensing volume to the nanoscale, as used in nanopore- or nanoparticle-based sensors, because nanoparticles are ubiquitous in lification. Methods to improve response time typically focus on obtaining an intimate mixture between the sensor and the s le either by extending the length scale of nanoscale sensors using nanostructuring or by dispersing magnetic nanoparticles through the s le to capture the analyte. Loading nanoparticles with many biorecognition species is one solution to help address the challenge of selectivity. Many ex les in this Perspective explore the detection of prostate-specific antigen which enables a comparison between strategies. Finally, exciting future opportunities in developing single-molecule sensors and the requirements to go even lower in concentration are explored.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Wiley
Date: 15-07-2018
Abstract: Achieving stability with highly active Ru nanoparticles for electrocatalysis is a major challenge for the oxygen evolution reaction. As improved stability of Ru catalysts has been shown for bulk surfaces with low-index facets, there is an opportunity to incorporate these stable facets into Ru nanoparticles. Now, a new solution synthesis is presented in which hexagonal close-packed structured Ru is grown on Au to form nanoparticles with 3D branches. Exposing low-index facets on these 3D branches creates stable reaction kinetics to achieve high activity and the highest stability observed for Ru nanoparticle oxygen evolution reaction catalysts. These design principles provide a synthetic strategy to achieve stable and active electrocatalysts.
Publisher: Wiley
Date: 19-09-2019
Abstract: Magnetic nanoparticles (MNPs) are of high significance in sensing as they provide viable solutions to the enduring challenges related to lower detection limits and nonspecific effects. The rapid expansion in the applications of MNPs creates a need to overview the current state of the field of MNPs for sensing applications. In this review, the trends and concepts in the literature are critically appraised in terms of the opportunities and limitations of MNPs used for the most advanced sensing applications. The latest progress in MNP sensor technologies is overviewed with a focus on MNP structures and properties, as well as the strategies of incorporating these MNPs into devices. By looking at recent synthetic advancements, and the key challenges that face nanoparticle-based sensors, this review aims to outline how to design, synthesize, and use MNPs to make the most effective and sensitive sensors.
Publisher: Wiley
Date: 27-06-2016
Abstract: Silicon and germanium nanocrystals (NCs) are attractive materials owing to their unique size and surface-dependent optical properties. The optical properties of silicon and germanium NCs make them highly suitable for a range of applications, including bioimaging, light-emitting diodes, and solar cells. In this review, the solution synthesis, surface passivation, optical properties, biomedical applications, and cytotoxicity of silicon and germanium NCs are compared and contrasted. Over the last 10 years, synthetic protocols have improved considerably, with size control readily achieved. Investigations have begun into a range of silicon and germanium nanostructures, including doped, alloy, and metal-semiconductor hybrid NCs, which represent the next generation of silicon and germanium nanomaterials. Silicon and germanium NCs are actively researched for a wide array of biomedical applications, including, long-term in vivo cellular imaging, fluorescent nanocarriers for drug delivery, and as contrast agents for magnetic resonance imaging (MRI). Cytotoxicity studies have shown the low toxicity of Si NCs, while demonstrating that Ge NCs are less toxic than CdSe NCs at similar concentrations, giving these materials a strong future in nanomedicine applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2005
DOI: 10.1039/B416069J
Abstract: Silicon nanocrystals with a uniform size distribution were synthesized in inverse micelles using powerful hydride reducing agents. The silicon nanocrystals surfaces were then stabilized with 1-heptene to produce particles with strong blue photoluminescence.
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.WATRES.2014.05.055
Abstract: Rotavirus (RoV) and adenovirus (AdV) are important viral pathogens for the risk analysis of drinking water. Despite this, little is known about their retention and transport behaviors in porous media due to a lack of representative surrogates. We developed RoV and AdV surrogates by covalently coupling 70-nm sized silica nanoparticles with specific proteins and a DNA marker for sensitive detection. Filtration experiments using beach sand columns demonstrated the similarity of the surrogates' concentrations, filtration efficiencies and attachment kinetics to those of the target viruses. The surrogates showed the same magnitude of concentration reduction as the viruses. Conversely, MS2 phage (a traditional virus model) over-predicted concentrations of AdV and RoV by 1- and 2-orders of magnitude respectively. The surrogates remained stable in size, surface charge and DNA concentration for at least one year. They can be easily and rapidly detected down to a single particle. Preliminary tests suggest that they were readily detectable in a number of environmental waters and treated effluent. With up-scaling validation in pilot trials, the surrogates developed here could be a cost-effective new tool for studying virus retention and transport in porous media. Ex les include assessing filter efficacy in water and wastewater treatment, tracking virus migration in groundwater after effluent land disposal, and establishing safe setback distances for groundwater protection.
Publisher: Wiley
Date: 21-03-2019
DOI: 10.1002/JOR.24262
Abstract: Stress fractures (SFx) result from repetitive cyclical loading of bone. They are frequent athletic injuries and underlie atypical femoral fractures following long-term bisphosphonate (BP) therapy. We investigated the effect of a single PTH injection on the healing of SFx in the rat ulna. SFx was induced in 120 female Wistar rats (300 ± 15 g) during a single loading session. A single PTH (8 µg.100g
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9SC05611D
Abstract: Nanoparticles mimicking the three-dimensional architecture of enzymes where the reaction occurs down a channel isolated from bulk solution, referred here as nanozymes, were used to explore the impact of nano-confinement on electrocatalytic reactions.
Publisher: Springer Science and Business Media LLC
Date: 11-10-2019
DOI: 10.1038/S41467-019-12615-6
Abstract: The nascent field of nanotechnology-enabled metallurgy has great potential. However, the role of eutectic alloys and the nature of alloy solidification in this field are still largely unknown. To demonstrate one of the promises of liquid metals in the field, we explore a model system of catalytically active Bi-Sn nano-alloys produced using a liquid-phase ultrasonication technique and investigate their phase separation, surface oxidation, and nucleation. The Bi-Sn ratio determines the grain boundary properties and the emergence of dislocations within the nano-alloys. The eutectic system gives rise to the smallest grain dimensions among all Bi-Sn ratios along with more pronounced dislocation formation within the nano-alloys. Using electrochemical CO 2 reduction and photocatalysis, we demonstrate that the structural peculiarity of the eutectic nano-alloys offers the highest catalytic activity in comparison with their non-eutectic counterparts. The fundamentals of nano-alloy formation revealed here may establish the groundwork for creating bimetallic and multimetallic nano-alloys.
Publisher: American Chemical Society (ACS)
Date: 23-10-2020
Publisher: Research Square Platform LLC
Date: 29-09-2023
Publisher: Wiley
Date: 08-07-2005
Publisher: MDPI AG
Date: 16-01-2012
DOI: 10.3390/NANO2010054
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0TC04702C
Abstract: The versatile qualities of gold coated magnetic nanoparticles for both optical and electrochemical detection, as well as the separation of analytes, make them an excellent choice for ultrasensitive biosensing applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NA00376B
Abstract: Magnetic nanoparticles coated with a glycan-catechol adduct, selected from a library created through a simple condensation reaction and an enzyme-catalysed reaction, were assessed as MRI contrast agents.
Publisher: Wiley
Date: 28-03-2008
Publisher: American Chemical Society (ACS)
Date: 24-04-2013
DOI: 10.1021/CG4001973
Publisher: American Chemical Society (ACS)
Date: 22-02-2016
Publisher: SPIE
Date: 28-12-2005
DOI: 10.1117/12.639524
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CC06300H
Abstract: Monodisperse iron nanoparticles are synthesized via successive seed-mediated growth reactions. By performing additional growth reactions, the nanoparticles’ magnetic character post-surface oxidation is tuned from superparamagnetic to ferromagnetic.
Publisher: Wiley
Date: 30-08-2019
Abstract: Alexa Fluor 647 is a widely used fluorescent probe for cell bioimaging and super-resolution microscopy. Herein, the reversible fluorescence switching of Alexa Fluor 647 conjugated to bovine serum albumin (BSA) and adsorbed onto indium tin oxide (ITO) electrodes under electrochemical potential control at the level of single protein molecules is reported. The modulation of the fluorescence as a function of potential was observed using total internal reflectance fluorescence (TIRF) microscopy. The fluorescence intensity of the Alexa Fluor 647 decreased, or reached background levels, at reducing potentials but returned to normal levels at oxidizing potentials. These electrochemically induced changes in fluorescence were sensitive to pH despite that BSA-Alexa Fluor 647 fluorescence without applied potential is insensitive to pH between values of 4-10. The observed pH dependence indicated the involvement of electron and proton transfer in the fluorescence switching mechanism.
Publisher: Wiley
Date: 29-04-2020
Publisher: Wiley
Date: 20-12-2022
Abstract: We propose a theoretical model for the influence of confinement on biomolecular binding at the single-molecule scale at equilibrium, based on the change of the number of microstates (localization and orientation) upon reaction. Three cases are discussed: DNA sequences shorter and longer than the single strain DNA Kuhn length and spherical proteins, confined into a spherical container (liposome, droplet, etc.). The influence of confinement is found to be highly dependent on the molecular structure and significant for large molecules (relative to container size).
Publisher: Elsevier BV
Date: 11-2016
Publisher: Wiley
Date: 13-07-2020
Publisher: Public Library of Science (PLoS)
Date: 20-02-2013
Publisher: American Chemical Society (ACS)
Date: 25-09-2014
DOI: 10.1021/AR500215V
Abstract: Understanding and unlocking the potential of semiconductor nanocrystals (NCs) is important for future applications ranging from biomedical imaging contrast agents to the next generation of solar cells and LEDs. Silicon NCs (Si NCs) have key advantages compared with other semiconductor NCs due to silicon's high natural abundance, low toxicity and strong biocompatibility, and unique size, and surface dependent optical properties. In this Account, we review and discuss the synthesis, surface modification, purification, optical properties, and applications of Si NCs. The synthetic methods used to make Si NCs have improved considerably in the last 5-10 years highly monodisperse Si NCs can now be produced on the near gram scale. Scaled-up syntheses have allowed scientists to drive further toward the commercial utilization of Si NCs. The synthesis of doped Si NCs, through addition of a simple elemental precursor to a reaction mixture or by the production of a single source precursor, has shown great promise. Doped Si NCs have demonstrated unique or enhanced properties compared with pure Si NCs, for ex le, magnetism due to the presence of magnetic metals like Fe and Mn. Surface reactions have reached a new level of sophistication where organic (epoxidation and diol formation) and click (thiol based) chemical reactions can be carried out on attached surface molecules. This has led to a wide range of biocompatible functional groups as well as a degree of emission tuneability. The purification of Si NCs has been improved through the use of size separation columns and size selective precipitation. These purification approaches have yielded highly monodisperse and pure Si NCs previously unachieved. This has allowed scientists to study the size and surface dependent properties and toxicity and enabled the use of Si NCs in biomedical applications. The optical properties of Si NCs are complex. Using a combination of characterization techniques, researchers have explored the relation between the optical properties and the size, surface functionalization, and preparation method. This work has led to a greater fundamental understanding of the unique optical properties of Si NCs. Si NCs are being studied for a wide range of important applications, including LEDS with tunable electroluminescence ranging from NIR to yellow, the encapsulation of Si NCs within micelles terminated with proteins to allow targeted in vivo imaging of cells, Si NC-polymer hybrid solar cells, and the use of Si NCs in battery anodes with high theoretical capacity and good charge retention.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0CC08068C
Abstract: A rapid, selective, and highly sensitive electrochemical-based sensing platform that uses the Au@MNPs as dispersible electrodes for quantifying programmed-death ligand 1 (PD- L1 ) levels directly in undiluted whole blood.
Publisher: Wiley
Date: 30-08-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5NR07413D
Abstract: Branched palladium nanomaterials synthesised using a seeded growth approach for enhanced Suzuki-cross coupling reactions.
Publisher: Wiley
Date: 29-11-2022
Abstract: Structural defects are ubiquitous for polycrystalline perovskite films, compromising device performance and stability. Herein, a universal method is developed to overcome this issue by incorporating halide perovskite quantum dots (QDs) into perovskite polycrystalline films. CsPbBr 3 QDs are deposited on four types of halide perovskite films (CsPbBr 3 , CsPbIBr 2 , CsPbBrI 2 , and MAPbI 3 ) and the interactions are triggered by annealing. The ions in the CsPbBr 3 QDs are released into the thin films to passivate defects, and concurrently the hydrophobic ligands of QDs self‐assemble on the film surfaces and grain boundaries to reduce the defect density and enhance the film stability. For all QD‐treated films, PL emission intensity and carrier lifetime are significantly improved, and surface morphology and composition uniformity are also optimized. Furthermore, after the QD treatment, light‐induced phase segregation and degradation in mixed‐halide perovskite films are suppressed, and the efficiency of mixed‐halide CsPbIBr 2 solar cells is remarkably improved to over 11% from 8.7%. Overall, this work provides a general approach to achieving high‐quality halide perovskite films with suppressed phase segregation, reduced defects, and enhanced stability for optoelectronic applications.
Publisher: Wiley
Date: 12-2020
DOI: 10.1002/ALZ.041609
Publisher: American Chemical Society (ACS)
Date: 10-04-2023
Publisher: American Chemical Society (ACS)
Date: 05-04-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CY00177B
Abstract: Ru nanoparticles are prepared via solvothermal synthesis with allotropism control. Both fcc and hcp s les are active catalysts for the hydrogen evolution reaction, but the hcp s le is stable during 12 hour operation.
Publisher: American Chemical Society (ACS)
Date: 20-10-2009
DOI: 10.1021/JA906804F
Abstract: Highly mondispersed SnS nanocrystals have been synthesized using ethanolamine ligands. SnS nanocrystals are small enough to be in the quantum confinement regime.
Publisher: Springer Science and Business Media LLC
Date: 15-09-2016
Publisher: American Chemical Society (ACS)
Date: 17-02-2010
DOI: 10.1021/JP910354Q
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9MH00664H
Abstract: This focus article looks at how nanoparticle shape affects cellular internalisation of nanoparticles and what different analysis methods can tell us.
Publisher: Research Square Platform LLC
Date: 11-2022
DOI: 10.21203/RS.3.RS-2155469/V1
Abstract: The wide range of potential surface configurations in high entropy alloy nanocatalysts (HEAs) offer substantial degrees of freedom to tune their catalytic properties. This complexity in possible atomic arrangements, however, presents a significant challenge in resolving active structural motifs, preventing the establishment of structure-function relationships for rational catalyst optimization. Herein, we present a methodology for creating sub 5 nm HEAs using an aqueous-based peptide-directed route. Using a combination of synchrotron scattering and spectroscopy techniques, HEA structure models are constructed from stochastic modelling of experimental datasets and showcase a clear peptide-induced influence on atomic-structure and chemical miscibility. Analysis of our models allow for the construction of structure-function correlations applied to electrochemical methanol oxidation reactions, revealing the complex interactions between multiple metals that lead to improved catalytic properties. Our results showcase a viable strategy for elucidating structure-function relationship in HEAs, prospectively providing a pathway for future materials design.
Publisher: American Chemical Society (ACS)
Date: 14-12-2023
Publisher: Wiley
Date: 10-07-2022
Abstract: Graphene edges exhibit a highly localized density of states that result in increased reactivity compared to its basal plane. However, exploiting this increased reactivity to anchor and tune the electronic states of single atom catalysts (SACs) remains elusive. To investigate this, a method to anchor Pt SACs with ultra‐low mass loadings at the edges of edge‐rich vertically aligned graphene (as low as 0.71 µg Pt cm –2 ) is developed. Angle‐dependent X‐ray absorption spectroscopy and density‐functional theory calculations reveal that edge‐anchored Pt SACs has a robust coupling with the π‐electrons of graphene. This interaction results in a higher occupancy of the Pt 5d orbital, shifting the d ‐band center toward the Fermi level, improving the adsorption of *H for the hydrogen evolution reaction (HER). Pt primarily coordinated to the graphene edge shows improved alkaline HER performance compared to Pt coordinated in mixed environments (turnover frequencies of 22.6 and 10.9 s –1 at an overpotential of 150 mV, respectively). This work demonstrates an effective route to engineering the coordination environment of Pt SACs by using the graphene edge for enhanced energy conversion reactions.
Publisher: Wiley
Date: 13-12-2021
Abstract: Bimetallic silver‐copper electrocatalysts are promising materials for electrochemical CO 2 reduction reaction (CO 2 RR) to fuels and multi‐carbon molecules. Here, we combine Ag core orous Cu shell particles, which entrap reaction intermediates and thus facilitate the formation of C 2+ products at low overpotentials, with gas diffusion electrodes (GDE). Mass transport plays a crucial role in the product selectivity in CO 2 RR. Conventional H‐cell configurations suffer from limited CO 2 diffusion to the reaction zone, thus decreasing the rate of the CO 2 RR. In contrast, in the case of GDE‐based cells, the CO 2 RR takes place under enhanced mass transport conditions. Hence, investigation of the Ag core orous Cu shell particles at the same potentials under different mass transport regimes reveals: (i) a variation of product distribution including C 3 products, and (ii) a significant change in the local OH ‐ activity under operation.
Publisher: American Chemical Society (ACS)
Date: 13-09-2018
Publisher: American Chemical Society (ACS)
Date: 16-10-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA02513H
Abstract: Black phosphorus quantum dots exhibit an impressive catalytic activity for oxygen evolution reaction.
Publisher: Wiley
Date: 16-12-2005
Publisher: Wiley
Date: 20-01-2012
Publisher: American Chemical Society (ACS)
Date: 25-08-2019
DOI: 10.1021/JACS.9B07310
Publisher: Wiley
Date: 26-03-2019
Abstract: Branched nanoparticles are one of the most promising nanoparticle catalysts as their branch sizes and surfaces can be tuned to enable both high activity and stability. Understanding how the crystallinity and surface facets of branched nanoparticles affect their catalytic performance is vital for further catalyst development. In this work, a synthesis is developed to form highly branched ruthenium (Ru) nanoparticles with control of crystallinity. It is shown that faceted Ru branched nanoparticles have improved stability and activity in the oxygen evolution reaction (OER) compared with polycrystalline Ru nanoparticles. This work achieves a low 180 mV overpotential at 10 mA cm
Publisher: American Chemical Society (ACS)
Date: 02-10-2018
DOI: 10.1021/JACS.8B09402
Abstract: A major synthetic challenge is to make metal nanoparticles with nanosized branches and well-defined facets for high-performance catalysts. Herein, we introduce a mechanism that uses the growth of hexagonal crystal structured branches off cubic crystal structured core nanoparticles. We control the growth to form Pd-core Ru-branch nanoparticles that have nanosized branches with low index Ru facets. We demonstrate that the branched and faceted structural features of the Pd-Ru nanoparticles retain high catalytic activity while also achieving high stability for the oxygen evolution reaction.
Publisher: Future Medicine Ltd
Date: 03-2020
Abstract: Nanoparticle (NP)-based magnetic contrast agents have opened the potential for MRI to be used for early diagnosis of Alzheimer’s disease (AD). This article aims to review the current progress of research in this field. A comprehensive literature search was performed based on PubMed, Medline, EMBASE, PsychINFO and Scopus databases using the following terms: ‘Alzheimer’s disease’ AND ‘nanoparticles’ AND ‘Magnetic Resonance Imaging.’ 33 studies were included that described the development and utility of various NPs for AD imaging, including their coating, functionalization, MRI relaxivity, toxicity and bioavailability. NPs show immense promise for neuroimaging, due to superior relaxivity and biocompatibility compared with currently available imaging agents. Consistent reporting is imperative for further progress in this field.
Publisher: Trans Tech Publications, Ltd.
Date: 07-2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.701.3
Abstract: Nanoscale alpha zinc phosphide (α-Zn 3 P 2 ) particles are a class of promising opto-electronic materials which have attracted worldwide attention. The synthetic protocols pertaining to α-Zn 3 P 2 nanoparticles have been largely based on the use of costly, pyrophoric and toxic phosphines precursors. We reported here the results of our investigation into the viability of fabricating crystalline α-Zn 3 P 2 nanoparticles using phosphorous pentabromide (PBr 5 ) as precursor via an air-stable solid hydrogen phosphide (PH) x intermediate. HRTEM analysis revealed the best s le as spherical crystalline α-Zn 3 P 2 nanoparticles with diameter found to be 5.8±2.1 nm. These particles exhibited photoluminescence centered at 470 nm (2.6 eV), blue-shifted by 1.2 eV from the 1.4 eV of bulk α-Zn 3 P 2 .
Publisher: IOP Publishing
Date: 06-2020
Abstract: We report a facile one-pot solution phase synthesis of one-dimensional Ge 1− x Sn x nanowires. These nanowires were synthesized in situ via a solution-liquid-solid (SLS) approach in which triphenylchlorogermane was reduced by sodium borohydride in the presence of tin nanoparticle seeds. Straight Ge 1− x Sn x nanowires were obtained with an average diameter of 60 ± 20 nm and an approximate aspect ratio of 100. Energy-dispersive x-ray spectroscopy (EDX) and powder x-ray diffraction (PXRD) analysis revealed that tin was homogeneously incorporated within the germanium lattices at levels up to 10 at%, resulting in a measured lattice constant of 0.5742 nm. The crystal structure and growth orientation of the nanowires were investigated using high-resolution transmission electron microscopy (HRTEM). The nanowires adopted a face-centred-cubic structure with in idual wires exhibiting growth along either the 〈111〉, 〈110〉 or 〈112〉 directions, in common with other group IV nanowires. Growth in the 〈112〉 direction was found to be accompanied by longitudinal planar twin defects.
Publisher: American Chemical Society (ACS)
Date: 16-02-2021
Publisher: American Chemical Society (ACS)
Date: 28-12-2012
DOI: 10.1021/JA210209R
Abstract: This Communication describes the synthesis of highly monodispersed 12 nm nickel nanocubes. The cubic shape was achieved by using trioctylphosphine and hexadecylamine surfactants under a reducing hydrogen atmosphere to favor thermodynamic growth and the stabilization of {100} facets. Varying the metal precursor to trioctylphosphine ratio was found to alter the nanoparticle size and shape from 5 nm spherical nanoparticles to 12 nm nanocubes. High-resolution transmission electron microscopy showed that the nanocubes are protected from further oxidation by a 1 nm NiO shell. Synchrotron-based X-ray diffraction techniques showed the nickel nanocubes order into [100] aligned arrays. Magnetic studies showed the nickel nanocubes have over 4 times enhancement in magnetic saturation compared to spherical superparamagnetic nickel nanoparticles.
Publisher: MDPI AG
Date: 11-12-2051
Abstract: In this work, a pH-responsive drug-carrier based on chitosan-silica nanospheres was developed as a carrier for Albendazole (ABZ), a poorly water-soluble anthelmintic drug. Spherical silica nanoparticles were obtained by Stöber method and further etched to obtain mesoporous particles with sizes ranging from 350 to 400 nm. The specific BET area of nanoparticles increased from 15 m2/g to 150 m2/g for etched silica, which also exhibited a uniform pore size distribution. X-ray powder diffraction showed the presence of amorphous phase of silica and a low-intensity peak attributed to ABZ for the drug-loaded nanoparticles. A uniform layer of chitosan was obtained ranging from 10 to 15 nm in thickness due to the small concentration of chitosan used (0.45 mg of chitosan/mg of SiO2). The in vitro evaluation of hybrid nanoparticles was performed using four cervical cancer cell lines CaSki, HeLa, SiHa and C33A, showing a significant reduction in cell proliferation ( %) after 72 h. Therefore, we confirmed the encapsulation and bioavailability of the drug, which was released in a controlled way, and the presence of chitosan delayed the release, which could be of interest for the development of prolonged release drug delivery systems.
Publisher: American Chemical Society (ACS)
Date: 14-05-2003
DOI: 10.1021/LA026993R
Publisher: American Chemical Society (ACS)
Date: 17-06-2022
DOI: 10.1021/JACS.2C04911
Abstract: Creating high surface area nanocatalysts that contain stacking faults is a promising strategy to improve catalytic activity. Stacking faults can tune the reactivity of the active sites, leading to improved catalytic performance. The formation of branched metal nanoparticles with control of the stacking fault density is synthetically challenging. In this work, we demonstrate that varying the branch width by altering the size of the seed that the branch grows off is an effective method to precisely tune the stacking fault density in branched Ni nanoparticles. A high density of stacking faults across the Ni branches was found to lower the energy barrier for Ni
Publisher: SPIE
Date: 09-02-2006
DOI: 10.1117/12.647235
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8CC09476D
Abstract: Gold nanoraspberries were synthesized by a seed-mediated synthesis with polyethylene glycol-functionalized bisphosphonates.
Publisher: American Chemical Society (ACS)
Date: 15-09-2009
DOI: 10.1021/JA9065688
Abstract: In situ studies on the growth and evolution of platinum nanocrystals in solution were carried out using synchrotron-based X-ray diffraction (XRD) techniques. Ex situ low- and high-resolution transmission electron microscopy (TEM) were used to investigate the nanocrystal morphologies through the different growth stages. In a reaction with low precursor concentration, both XRD and TEM results show that growth occurs at a relatively slow rate and yields faceted morphologies, which are characteristic of a thermodynamically controlled regime. In contrast, the platinum nanocrystals in the high-concentration reaction form branched structures and grow at much greater rates under a kinetically controlled regime. Additionally the growth mechanism of the high-concentration reaction involves a morphology transformation from octapod-like shapes to porous nanostructures, which is brought about by a novel mechanism involving selective growth and etching processes that occur simultaneously and at comparable rates.
Publisher: American Chemical Society (ACS)
Date: 28-01-2020
DOI: 10.1021/JACS.9B13313
Abstract: Controlling which facets are exposed in nanocrystals is crucial to understanding different activity between ordered and disordered alloy electrocatalysts. We modify the degree of ordering of Pt
Publisher: American Chemical Society (ACS)
Date: 02-11-2021
DOI: 10.1021/ACS.NANOLETT.1C01855
Abstract: Nanopore blockade sensors were developed to address the challenges of sensitivity and selectivity for conventional nanopore sensors. To date, the parameters affecting the current of the sensor have not been elucidated. Herein, the impacts of nanopore size and charge and the shape, size, surface charge, and aggregation state of magnetic nanoparticles were assessed. The sensor was tolerant to all parameters contrary to predictions from electronic or geometric arguments on the current change. Theoretical models showed the greater importance of the polymers around nanoparticles and the access resistance of nanopores to the current, when compared with translocation-based nanopore sensors. The signal magnitude was dominated by the change in access resistance of ∼4.25 MΩ for all parameters, resulting in a robust system. The findings provide understandings of changes in current when nanopores are blocked, like in RNA trapping or nanopore blockade sensors, and are important for designing sensors based on nanopore blockades.
Publisher: American Chemical Society (ACS)
Date: 03-12-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2NR01897G
Abstract: This review outlines how nanoparticle structure and surface coating can be tailored to generate images with high signal and spatial resolution in vivo , which is crucial for developing magnetic particle imaging tracers for biomedical applications.
Publisher: American Chemical Society (ACS)
Date: 26-10-2009
DOI: 10.1021/NN9012252
Abstract: We report on a real-time in situ TEM study of the coalescence of in idual pairs of decahedral gold nanoparticles, which have been synthesized in solution. We observe the rate of growth of the neck that joins two particles during coalescence and compare this to classical continuum theory and to atomistic kinetic Monte Carlo simulations. We find good agreement between the observations and the simulations but not with the classical continuum model. This disagreement is attributed to the faceted nature of the particles.
Publisher: American Chemical Society (ACS)
Date: 23-09-2018
DOI: 10.1021/JACS.8B08664
Abstract: Enzymes are characterized by an active site that is typically embedded deeply within the protein shell thus creating a nanoconfined reaction volume in which high turnover rates occur. We propose nanoparticles with etched substrate channels as a simplified enzyme mimic, denominated nanozymes, for electrocatalysis. We demonstrate increased electrocatalytic activity for the oxygen reduction reaction using PtNi nanoparticles with isolated substrate channels. The PtNi nanoparticles comprise an oleylamine capping layer that blocks the external surface of the nanoparticles participating in the catalytic reaction. Oxygen reduction mainly occurs within the etched channels providing a nanoconfined reaction volume different from the bulk electrolyte conditions. The oxygen reduction reaction activity normalized by the electrochemically active surface area is enhanced by a factor of 3.3 for the nanozymes compared to the unetched nanoparticles and a factor of 2.1 compared to mesoporous PtNi nanoparticles that possess interconnecting pores.
Publisher: IEEE
Date: 02-2010
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CC03225G
Abstract: Gold coated magnetic nanoparticles (Au@MNPs) have become increasingly interesting to nanomaterial scientists due to their multifunctional properties and their potential in both analytical chemistry and nanomedicine.
Publisher: American Chemical Society (ACS)
Date: 04-02-2021
Publisher: Elsevier
Date: 2019
Publisher: OSA
Date: 2018
Publisher: Wiley
Date: 13-05-2021
Abstract: Hydrogen is increasingly viewed as a game‐changer in the clean energy sector. Renewable hydrogen production from water is industrialized by integrating water electrolysis and renewable electricity, but the current cost of water‐born hydrogen remains high though. An ideal scenario would be to produce value‐added chemicals along with hydrogen so the cost can be partially offset. Herein, facilitated bio‐hydrogen extraction and biomass‐derived chemical formation from sugar‐derived 5‐hydroxymethyfurfural (HMF) were achieved via the in‐situ transformation of cobalt‐bound electrocatalysts. The cyanide‐bound cobalt hydroxide exhibited a low voltage at 1.55 V at 10 mA cm −2 for bio‐hydrogen production, compared with an iridium catalyst (1.75 V). The interaction between the biomass intermediate and the cyanide ligand is suggested to be responsible for the improved activity.
Publisher: Springer Science and Business Media LLC
Date: 19-08-2021
DOI: 10.1007/S12274-021-3702-7
Abstract: Scanning electrochemical cell microscopy (SECCM) is increasingly applied to determine the intrinsic catalytic activity of single electrocatalyst particle. This is especially feasible if the catalyst nanoparticles are large enough that they can be found and counted in post-SECCM scanning electron microscopy images. Evidently, this becomes impossible for very small nanoparticles and hence, a catalytic current measured in one landing zone of the SECCM droplet cannot be correlated to the exact number of catalyst particles. We show, that by introducing a ruler method employing a carbon nanoelectrode decorated with a countable number of the same catalyst particles from which the catalytic activity can be determined, the activity determined using SECCM from many spots can be converted in the intrinsic catalytic activity of a certain number of catalyst nanoparticles.
Publisher: IOP Publishing
Date: 30-06-2006
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1FD00088H
Abstract: After introducing nanoelectrochemistry, this introductory lecture focuses on recent developments in two major application areas of nanoelectrochemistry electrocatalysis and using single entities in sensing.
Publisher: Wiley
Date: 03-09-2007
Publisher: IOP Publishing
Date: 06-07-2011
Publisher: Springer Science and Business Media LLC
Date: 27-10-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NR05802H
Abstract: High- and low-index faceted metal (Pt, Pd, Ru, Ir, Rh) nanoparticles designed for improved electrocatalytic activity and stability are reviewed.
Publisher: American Chemical Society (ACS)
Date: 21-05-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9NR07891F
Abstract: We report on the characterisation of the optical properties and dynamic behaviour of optically trapped single stimuli-responsive plasmonic nanoscale assemblies.
Publisher: American Chemical Society (ACS)
Date: 26-05-2022
DOI: 10.1021/ACS.ACCOUNTS.2C00140
Abstract: Branched metal nanoparticles have unique catalytic properties because of their high surface area with multiple branches arranged in an open 3D structure that can interact with reacting species and tailorable branch surfaces that can maximize the exposure of desired catalytically active crystal facets. These exceptional properties have led to the exploration of the roles of branch structural features ranging from the number and dimensions of branches at the larger scales to the atomic-scale arrangement of atoms on precise crystal facets. The fundamental significance of how larger-scale branch structural features and atomic-scale surface faceting influence and control the catalytic properties has been at the forefront of the design of branched nanoparticles for catalysis. Current synthetic advances have enabled the formation of branched nanoparticles with an unprecedented degree of control over structural features down to the atomic scale, which have unlocked opportunities to make improved nanoparticle catalysts. These catalysts have high surface areas with controlled size and surface facets for achieving exceedingly high activity and stability. The synthetic advancement has recently led to the use of branched nanoparticles as ideal substrates that can be decorated with a second active metal in the form of islands and single atoms. These decorated branched nanoparticles have new and highly effective catalytic active sites where both branch metal and decorating metal play essential roles during catalysis.In the opening half of this Account, we critically assess the important structural features of branched nanoparticles that control catalytic properties. We first discuss the role of branch dimensions and the number of branches that can improve the surface area but can also trap gas bubbles. We then investigate the atomic-scale structural features of exposed surface facets, which are critical for enhancing catalytic activity and stability. Well-defined branched nanoparticles have led to a fundamental understanding of how the branch structural features influence the catalytic activity and stability, which we highlight for the oxygen evolution reaction (OER) and biomass oxidation. In discussing recent breakthroughs for branched nanoparticles, we explore the opportunities created by decorated branched nanoparticles and the unique bifunctional active sites that are exposed on the branched nanoparticle surfaces. This class of catalysts is of rapidly growing importance for reactions including the hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR), where two exposed metals are required for efficient catalysis. In the second half of this Account, we explore recent advances in the synthesis of branched nanoparticles and highlight the cubic-core hexagonal-branch growth mechanism that has achieved excellent control of all of the important structural features, including branch dimensions, number of branches, and surface facets. We discuss the slow precursor reduction as an effective strategy for decorating metal islands with controlled loadings on the branched nanoparticle surfaces and the spread of these metal islands to form single-atom active sites. We envisage that the key synthetic and structural advances identified in this Account will guide the development of the next-generation electrocatalysts.
Publisher: American Chemical Society (ACS)
Date: 03-10-2019
DOI: 10.1021/JACS.9B07659
Abstract: The direct growth of Pt islands on lattice mismatched Ni nanoparticles is a major synthetic challenge and a promising strategy to create highly strained Pt atoms for electrocatalysis. By using very mild reaction conditions, Pt islands with tunable strain were formed directly on Ni branched particles. The highly strained 1.9 nm Pt-island on branched Ni nanoparticles exhibited high specific activity and the highest mass activity for hydrogen evolution (HER) in a pH 13 electrolyte. These results show the ability to synthetically tune the size of the Pt islands to control the strain to give higher HER activity.
Publisher: Cold Spring Harbor Laboratory
Date: 09-12-2020
DOI: 10.1101/2020.12.09.411876
Abstract: This experimental study aimed to investigate the feasibility of using silicon quantum dots doped with transition metals: scandium, copper and zinc as contrast agents for eventual application for the study of the tear film in eyes. Si-QDs were synthesized and characterized by transmission electron microscopy, photoluminescence, absorbance and transient absorption measurements. The fluorescence of Si-QDs was investigated when combined with TheraTears ® (a balanced electrolyte formula for dry eye therapy). An optical imaging system composed of a modified slit l biomicroscope combined with a high-resolution Zyla sCMOS camera, SOLIS software, custom-made optical mounts and emission filters (460 nm, 510 nm and 530 nm) were used for in vitro imaging of Si-QDs with TheraTears ® . The average size of Si-QDs was 2.65 nm. In vitro imaging of Sc-Si-QDs and Cu-Si-QDs indicated their stable and bright fluorescence with TheraTears ® . Sc-Si-QDs were significantly brighter compared to Cu-Si-QDs and Zn-Si-QDs, and the Zn-Si-QDs showed a tendency to clump in TheraTears ® . The fluorescence of the Si-QDs was detected down to a concentration of 0.01 µg/mL within a total volume of 5 µL. Cu-Si-QDs and Sc-Si-QDs showed brighter fluorescence than Zn-Si-QDs. However, Zn-Si-QDs and to a lesser extent, Cu-Si-QDs showed some aggregation at specific concentrations. Sc-Si-QDs are proposed as a better option for further development as an in vivo bioimaging agent to study the tear film dynamics.
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/CH12168
Abstract: We report the dramatic effect of rationally-designed phosphopeptides on the size and shape of iron-iron oxide core-shell nanoparticles prepared in a one-pot synthesis by sodium borohydride reduction of an iron salt. These phosphopeptides are effective at small ratios of peptide to metal, in contrast to the behaviour of conventional capping agents, which must be added at high concentration to control the particle growth.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9SE00038K
Abstract: Electron microscopy (EM), specifically in situ , is a powerful analytical and characterisation technique that is widely used to study electrode materials for battery applications.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-08-2022
Abstract: Lithium (Li) metal anode have shown exceptional potential for high-energy batteries. However, practical cell-level energy density of Li metal batteries is usually limited by the low areal capacity ( mAh cm −2 ) because of the accelerated degradation of high–areal capacity Li metal anodes upon cycling. Here, we report the design of hyperbranched vertical arrays of defective graphene for enduring deep Li cycling at practical levels of areal capacity ( mAh cm −2 ). Such atomic-to-macroscopic trans-scale design is rationalized by quantifying the degradation dynamics of Li metal anodes. High-energy Li metal cells are prototyped under realistic conditions with high cathode capacity ( mAh cm −2 ), low negative-to-positive electrode capacity ratio (1:1), and low electrolyte-to-capacity ratio (5 g Ah −1 ), which shed light on a promising move toward practical Li metal batteries.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5OB00822K
Abstract: The facile preparation of cell-targeted platinum nanoparticles (PtNPs) is described, using designed peptides that as a single molecule control PtNP cluster growth, stabilise clusters in aqueous suspension and enable attachment of a versatile range of cell-targeting ligands.
Publisher: American Chemical Society (ACS)
Date: 24-03-2023
Publisher: Wiley
Date: 31-05-2022
Abstract: Die Verwendung von Nanopartikeln und nanostrukturierten Elektroden ist in der Elektrokatalyse weit verbreitet. Diese nanometrischen Systeme enthalten je nach Geometrie Elemente des Nanoconfinements in unterschiedlichem Ausmaß, was sich viel stärker auf die Aktivität und Selektivität auswirken kann, als oft angenommen wird. In diesem Aufsatz identifizieren wir zunächst die Systeme, die unterschiedliche Grade von Nanoconfinement enthalten, und zeigen, wie sie die Aktivität und Selektivität elektrokatalytischer Reaktionen beeinflussen können. Anschließend wird ein grundlegendes Verständnis der Auswirkungen des Nanoconfinements auf die Elektrochemie und Elektrokatalyse vermittelt, das dank der Entwicklung neuer, atomar präziser Herstellungs‐ und Fertigungstechniken und Fortschritten bei der theoretischen Modellierung allmählich erschlossen wird. Diese Übersicht soll dabei helfen, die Nanostrukturierung nicht nur zur Vergrößerung der Oberfläche zu nutzen, sondern auch die thermodynamisch bedingten Skalierungsbeziehungen in der Elektrokatalyse zu durchbrechen.
Publisher: AIP Publishing
Date: 04-11-2014
DOI: 10.1063/1.4828364
Abstract: In this study, the performance enhancement in silicon solar cell by inverted nanopyramid texturing and silicon quantum dot coating has been investigated. The inverted nanopyramid was fabricated by laser interference lithography and subsequent pattern transfer dry etching and KOH wet etching. The silicon quantum dots were synthesized by size controllable microemulsion technique and were characterized by transmission electron microscopy, UV-Vis spectroscopy, and photoluminescence spectroscopy techniques. The nanopyramid texturing with 700 nm period inverted pyramid reduced the reflection below 10% over broad wavelength region. The overall efficiency of solar cell increased by 47% by inverted nanopyramid texturing combined with silicon quantum dot coating.
Publisher: American Chemical Society (ACS)
Date: 14-09-2021
Publisher: American Chemical Society (ACS)
Date: 28-06-2011
DOI: 10.1021/CM200354D
Publisher: Wiley
Date: 30-05-2021
Abstract: Macropinocytosis is a consequence of oncogenic alterations of cancer cells while most healthy cells are non‐macropinocytic. It is currently unclear whether macropinocytic cancer cells can be targeted rather than healthy cells, by adjusting the shape and size of nanoparticles. Herein, the endocytosis of two differently shaped nanoparticles nanorods and nanospheres are compared in cancer and healthy cells. The cells are breast epithelial cancer cells (MCF7) and breast epithelial healthy cells (MCF10A) and pancreas cancer cells (PANC‐1 cells) and non‐tumourogenic patient‐derived cancer‐associated fibroblasts (CAFs). The endocytosis pathway is quantified by a combination of pair correlation microscopy and endocytosis inhibitors. MCF7 cells use clathrin‐mediated endocytosis and macropinocytosis to take up the nanorods while MCF10A cells use predominantly clathrin‐mediated endocytosis. Based on the comparison of endocytic behavior of cancer and healthy cells, MCF7 cells can be induced to take up more nanorods and suppress the metabolism and endocytosis of nanorods in MCF10A cells. The nanorods allow targeting to breast cancer MCF7 cells and pancreas cancer cells over the healthy cells. This study opens exciting possibilities for shape to target the cancer cells over healthy cells, by adjusting nanoparticle shape.
Publisher: American Institute of Physics
Date: 2009
DOI: 10.1063/1.3203257
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8NR05071F
Abstract: The creation of multiple emission pathways in quantum dots (QDs) is an exciting prospect with fundamental interest and optoelectronic potential.
Publisher: SPIE-Intl Soc Optical Eng
Date: 23-08-2017
Publisher: American Chemical Society (ACS)
Date: 21-09-2007
DOI: 10.1021/CM070818K
Publisher: American Chemical Society (ACS)
Date: 18-01-2018
DOI: 10.1021/ACS.LANGMUIR.7B02787
Abstract: Electrochemical DNA biosensors composed of a redox marker modified nucleic acid probe tethered to a solid electrode is a common experimental construct for detecting DNA and RNA targets, proteins, inorganic ions, and even small molecules. This class of biosensors generally relies on the binding-induced conformational changes in the distance of the redox marker relative to the electrode surface such that the charge transfer is altered. The conventional design is to attach the redox species to the distal end of a surface-bound nucleic acid strand. Here we show the impact of the position of the redox marker, whether on the distal or proximal end of the DNA monolayer, on the DNA interface electrochemistry. Somewhat unexpectedly, greater currents were obtained when the redox molecules were located on the distal end of the surface-bound DNA monolayer, notionally furthest away from the electrode, compared with currents when the redox species were located on the proximal end, close to the electrode. Our results suggest that a limitation in ion accessibility is the reason why smaller currents were obtained for the redox markers located at the bottom of the DNA monolayer. This understanding shows that to allow the quantification of the amount of redox labeled target DNA strand that hybridizes to probe DNA immobilized on the electrode surface, the redox species must be on the distal end of the surface-bound duplex.
Publisher: Springer Science and Business Media LLC
Date: 08-11-2016
Publisher: Springer Science and Business Media LLC
Date: 20-01-2021
DOI: 10.1038/S41467-020-20749-1
Abstract: All-inorganic CsPbI 3 perovskite quantum dots have received substantial research interest for photovoltaic applications because of higher efficiency compared to solar cells using other quantum dots materials and the various exciting properties that perovskites have to offer. These quantum dot devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. We demonstrate higher mechanical endurance of quantum dot films compared to bulk thin film and highlight the importance of further research on high-performance and flexible optoelectronic devices using nanoscale grains as an advantage. Specifically, we develop a hybrid interfacial architecture consisting of CsPbI 3 quantum dot/PCBM heterojunction, enabling an energy cascade for efficient charge transfer and mechanical adhesion. The ch ion CsPbI 3 quantum dot solar cell has an efficiency of 15.1% (stabilized power output of 14.61%), which is among the highest report to date. Building on this strategy, we further demonstrate a highest efficiency of 12.3% in flexible quantum dot photovoltaics.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0SC05990K
Abstract: The stability of bimetallic AgCu and PdCu catalysts for electrochemical CO 2 RR is investigated using the combination of operando and ex situ TEM. The local CO concentration is identified as the main link between activity, stability and selectivity.
Publisher: Wiley
Date: 08-06-2009
Publisher: American Chemical Society (ACS)
Date: 15-05-2023
Publisher: American Chemical Society (ACS)
Date: 21-04-2011
DOI: 10.1021/CM2002868
Publisher: American Chemical Society (ACS)
Date: 31-12-2013
DOI: 10.1021/JA311366K
Abstract: Recent successes in forming different shaped face centered cubic (fcc) metal nanostructures has enabled a greater understanding of nanocrystal growth mechanisms. Here we extend this understanding to the synthesis of hexagonally close packed (hcp) metal nanostructures, to form uniquely faceted ruthenium nanocrystals with a well-defined hourglass shape. The hourglass nanocrystals are formed in a three-step thermodynamic growth process with dodecylamine as the organic stabilizer. The hourglass nanocrystals are then shown to readily self-assemble to form a new type of nanocrystal superlattice.
Publisher: American Chemical Society (ACS)
Date: 22-07-2010
DOI: 10.1021/CG100857Y
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0CC07769K
Abstract: Pt islands with different sizes were grown on amorphous Ni nanoparticles, allowing the tuning of the Pt–Ni interface without changing the hydrogen binding energy of the Pt sites.
Publisher: Annual Reviews
Date: 12-06-2020
DOI: 10.1146/ANNUREV-ANCHEM-091619-092506
Abstract: Avoiding the growth of SiO x has been an enduring task for the use of silicon as an electrode material in dynamic electrochemistry. This is because electrochemical assays become unstable when the SiO x levels change during measurements. Moreover, the silicon electrode can be completely passivated for electron transfer if a thick layer of insulating SiO x grows on the surface. As such, the field of silicon electrochemistry was mainly developed by electron-transfer studies in nonaqueous electrolytes and by applications employing SiO x -passivated silicon-electrodes where no DC currents are required to cross the electrode/electrolyte interface. A solution to this challenge began by functionalizing Si–H electrodes with monolayers based on Si–O–Si linkages. These monolayers have proven very efficient to avoid SiO x formation but are not stable for a long-term operation in aqueous electrolytes due to hydrolysis. It was only with the development of self-assembled monolayers based on Si–C linkages that a reliable protection against SiO x formation was achieved, particularly with monolayers based on α,ω-dialkynes. This review discusses in detail how this surface chemistry achieves such protection, the electron-transfer behavior of these monolayer-modified silicon surfaces, and the new opportunities for electrochemical applications in aqueous solution.
Publisher: American Chemical Society (ACS)
Date: 18-11-2015
Abstract: Bimetallic nanostructures show exciting potential as materials for effective photothermal hyperthermia therapy. We report the seed-mediated synthesis of palladium-gold (Pd-Au) nanostructures containing multiple gold nanocrystals on highly branched palladium seeds. The nanostructures were synthesized via the addition of a gold precursor to a palladium seed solution in the presence of oleylamine, which acts as both a reducing and a stabilizing agent. The interaction and the electronic coupling between gold nanocrystals and between palladium and gold broadened and red-shifted the localized surface plasmon resonance absorption maximum of the gold nanocrystals into the near-infrared region, to give enhanced suitability for photothermal hyperthermia therapy. Pd-Au heterostructures irradiated with an 808 nm laser light caused destruction of HeLa cancer cells in vitro, as well as complete destruction of tumor xenographs in mouse models in vivo for effective photothermal hyperthermia.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0NR00864H
Abstract: The growth of carbon nanotubes, and the role of the catalyst in this process, is only partially understood. Here we report real-time TEM observations of a partially embedded crystalline catalyst particle retracting from the hollow of a growing carbon nanotube, followed by a subsequent closure of the tube. The retraction is explained by size-dependent capillary forces, demonstrating the importance of capillary forces in the interaction between the catalyst and the nanotube. The observed crystallinity of the particle provides evidence that carbon nanotube growth in these circumstances does not require a molten catalyst, and closure of the tube suggests a carbon concentration gradient is involved in the growth.
Publisher: American Chemical Society (ACS)
Date: 27-10-2022
Abstract: Glioblastoma is hard to be eradicated partly because of the obstructive blood-brain barrier (BBB) and the dynamic autophagy activities of glioblastoma. Here, hydroxychloroquine (HDX)-loaded yolk-shell upconversion nanoparticle (UCNP)@Zn
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR00718F
Abstract: Investigation of how the organometallic precursor controls the size and monodispersity of iron nanoparticles made from decomposition solution-phase synthesis.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CC13416G
Abstract: Here we report a new, bench-top synthesis for iron/iron oxide core/shell nanoparticles via the thermal decomposition of Fe(η(5)-C(6)H(3)Me(4))(2). The iron/iron oxide core/shell nanoparticles are superparamagnetic at room temperature and show improved negative contrast in T(2)-weighted MR imaging compared to pure iron oxides nanoparticles, and have a transverse relaxivity (r(2)) of 332 mM(-1) s(-1).
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5CY01205H
Abstract: Different types of surface defects are needed for specific types of catalytic reactions, and can be promoted or suppressed by varying the temperature and rates during the early stages of growth.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Wiley
Date: 16-10-2020
Publisher: American Chemical Society (ACS)
Date: 06-12-2021
Publisher: Springer Science and Business Media LLC
Date: 20-07-2020
Publisher: Elsevier
Date: 2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1SC04656J
Abstract: It was recently shown that it is possible to exploit the nanoparticle shape to selectively target endocytosis pathways found in cancer and not healthy cells.
Publisher: Wiley
Date: 02-09-2019
Publisher: American Chemical Society (ACS)
Date: 27-10-2020
Publisher: SPIE
Date: 22-12-2015
DOI: 10.1117/12.2202510
Publisher: Wiley
Date: 19-03-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CC02176H
Abstract: The synthesis of inorganic fullerene (IF) nanoparticles and IF hollow spheres of titanium disulfide by a simple colloidal route is reported. The injection temperature of the titanium precursor into the solvent mixture was found to be important in controlling the morphology.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2AY01782B
Abstract: Herein is shown an approach to using gold coated magnetic nanoparticles as dispersible electrodes for ultralow detection of circulating nucleic acids that requires no calibration to achieve quantitative information.
Publisher: Wiley
Date: 27-07-2006
Publisher: American Chemical Society (ACS)
Date: 20-02-2013
DOI: 10.1021/NN4000644
Publisher: Elsevier BV
Date: 02-2021
Publisher: American Chemical Society (ACS)
Date: 10-2002
DOI: 10.1021/JP0256847
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0NR00276C
Abstract: Platinum and palladium are important catalysts for a wide variety of industrial processes. With the increasing demands of these materials, the development of high-performance catalysts is an important area of research, and as a result, shape control synthesis has become one of the leading research focuses. This minireview surveys the different approaches in solution-phase synthesis that have been successfully adopted for achieving shaped platinum and palladium nanoparticles that are enclosed with specific crystallographic facets. In addition, catalytic studies of the shaped nanoparticles are highlighted, in which promising results have been reported in terms of enhanced activity and selectivity. The future outlook discusses the aspects in synthesis and catalysis to be considered for the development of highly efficient and effective catalysts.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0SC04552G
Abstract: Selective detection of attomolar proteins was achieved using gold lined nanopores in a nanopore blockade sensor.
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.BIOS.2018.06.066
Abstract: The integration of plasmonic nanoparticles into biosensors has the potential to increase the sensitivity and dynamic range of detection, through the use of single nanoparticle assays. The analysis of the localized surface plasmon resonance (LSPR) of plasmonic nanoparticles has allowed the limit of detection of biosensors to move towards single molecules. However, due to complex equipment or slow analysis times, these technologies have not been implemented for point-of-care detection. Herein, we demonstrate an advancement in LSPR analysis by presenting a technique, which utilizes an inexpensive CMOS-equipped digital camera and a dark-field microscope, that can analyse the λ
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC02730K
Abstract: Well-defined second-generation hot spots in end-to-end assembled gold nanobipyramids exhibit sufficient enhancement of the plasmonic field for single molecule detection.
Publisher: Public Library of Science (PLoS)
Date: 29-05-2013
Publisher: Springer Science and Business Media LLC
Date: 25-03-2022
Publisher: Wiley
Date: 17-06-2022
Abstract: Gold‐coated magnetic nanoparticles are key materials for the fast separation and ultrasensitive detection of analytes in magnetoplasmonic sensors. However, the synthesis of gold‐coated magnetic nanoparticles typically requires small‐scale, colloidal methods over hours or days and often results in incomplete shells with variable optical properties. A robust, rapid, and scalable synthesis method is still needed to reliably form a complete gold nanoshell around magnetic nanoparticles. Herein, a new methodology for the synthesis of gold‐coated magnetic nanoparticles via a flow‐based manufacturing system that can easily be scaled up is presented. The developed method first produces gold‐seeded silica coated magnetic nanoparticles and then a complete, tunable gold shell with relatively uniform size and shape. The flow‐based method can be performed in a total time of less than 2 min, enabling rapid and complete gold coating. The particles show both excellent magnetic and plasmonic properties, which facilitates application as biosensing agents in dark‐field microscopy and surface‐enhanced Raman scattering.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC43097A
Abstract: Here, we report the effect of oleylamine (OLA) stabilizing molecules on the stability of iron-iron oxide core-shell nanoparticles in the electron beam. The presence of excess OLA (>50 wt%) induces the structural transformation in the highly crystalline, core-shell structures to form hollow iron oxide nanoparticles after 120 s of electron beam exposure.
Publisher: Springer Science and Business Media LLC
Date: 21-07-2022
DOI: 10.1038/S41560-022-01078-7
Abstract: Understanding carrier loss mechanisms at microscopic regions is imperative for the development of high-performance polycrystalline inorganic thin-film solar cells. Despite the progress achieved for kesterite, a promising environmentally benign and earth-abundant thin-film photovoltaic material, the microscopic carrier loss mechanisms and their impact on device performance remain largely unknown. Herein, we unveil these mechanisms in state-of-the-art Cu 2 ZnSnSe 4 (CZTSe) solar cells using a framework that integrates multiple microscopic and macroscopic characterizations with three-dimensional device simulations. The results indicate the CZTSe films have a relatively long intragrain electron lifetime of 10–30 ns and small recombination losses through bandgap and/or electrostatic potential fluctuations. We identify that the effective minority carrier lifetime of CZTSe is dominated by a large grain boundary recombination velocity (~10 4 cm s −1 ), which is the major limiting factor of present device performance. These findings and the framework can greatly advance the research of kesterite and other emerging photovoltaic materials.
Start Date: 2014
End Date: 2021
Funder: Australian Research Council
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