ORCID Profile
0000-0002-1634-5498
Current Organisation
North Metropolitan Health Service
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Medical Biotechnology | Functional Materials | Biomedical Instrumentation | Colloid and Surface Chemistry | Soil Chemistry (excl. Carbon Sequestration Science) | Materials Engineering | Medical Biotechnology Diagnostics (incl. Biosensors)
Veterinary Diagnostics | Expanding Knowledge in the Environmental Sciences | Diagnostic Methods | Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in Engineering | Scientific Instruments |
Publisher: Elsevier BV
Date: 09-2015
Publisher: Wiley
Date: 09-06-2021
Abstract: Electrochemical immunosensors are an emerging technology for the fast, sensitive, and reliable diagnosis of diseases from bodily fluids. These sensors work by detecting a change in current upon analyte binding to an immuno‐functionalized electrode. Current methods of electrode functionalization are lengthy processes involving self‐assembled monolayer formation and wet chemistry biofunctionalization. Herein, thin films deposited from the plasma phase of oxazoline precursors are investigated and optimized as an alternative approach for electrode functionalization. The plasma‐enabled method has the advantage of being substrate independent and allows the spontaneous binding of biomolecules in physiological buffer. Surface sensitive analysis techniques are employed to characterize the thickness, reactivity, and stability of the thin films before investigating their electrochemical properties on indium tin oxide and gold electrodes including the feasibility to reduce charge transfer resistance with gold nanoparticles. Last, these films are employed to develop an immunosensor for the detection of free epithelial cell adhesion molecule with a limit of detection of 8.7 ng mL −1 .
Publisher: Wiley
Date: 22-10-2016
Publisher: Wiley
Date: 31-01-2023
DOI: 10.1002/JLCR.4013
Abstract: Since first becoming commercially available in 2018, the PET radiopharmaceutical [ 18 F]PSMA‐1007 has been used widely for the diagnosis and staging of prostate cancer. A pharmacopoeia monograph first became available in 2021, prescribing a radiochemical purity specification of %, based on analytical results from both TLC (for [ 18 F]fluoride impurity alone) and HPLC (for all other 18 F‐impurities). Though this monograph has provided clarity for the quality control testing of [ 18 F]PSMA‐1007, it prescribes a HPLC method using phosphate buffer mobile phase that may present a risk of precipitation of phosphate salts in the HPLC system. The method also requires specialised hardware not immediately available to all laboratories. This work describes the development of a simple, rapid reversed‐phase HPLC method utilising 0.1 M ammonium formate mobile phase for the accurate assessment of both [ 18 F]fluoride impurity and overall radiochemical purity in a single test. This method is especially useful for assessment of product stability over time. A more accurate TLC method for [ 18 F]fluoride impurity is also described.
Publisher: Wiley
Date: 27-12-2021
DOI: 10.1002/MDS3.10160
Publisher: American Scientific Publishers
Date: 09-2021
Abstract: An electrochemical biosensor for the detection of glucose is realized by immobilizing glucose oxidase (GOx) enzyme onto titanium dioxide nanotube arrays by a coupling encapsulation process. We present details of a robust fabrication technique that results in a durable and reproducible sensor characteristics. The TiO 2 nanotube arrays are grown directly on a titanium substrate by a potentiostatic anodization process in a water and ethylene-glycol mixture solution, which contains ammonium fluoride. An electropolymerization process was also performed to enhance interfacial adhesion between GOx and TiO 2 nanotubes. Detection of glucose concentrations was achieved with a linear response in the range of 0.01 to 0.2 mM. Investigation of enhanced sensitivity by increasing the count, the length, and the cross-section of the nanotubes was also carried out. Surface morphologies of Ti substrate were examined by scanning electron microscopy to optimize the anodization process and thus the TiO 2 /Ti nanotube dimensions. We utilized a time-based erometric response for the quantitative determination of hydrogen peroxide concentration through electro-reduction reaction with a bare TiO 2 /Ti nanotube-array electrodes, thus providing a reference for the determination of glucose levels with a GOx-coated TiO 2 /Ti nanotube array electrodes. Detection levels down to 5.2 μ M were recorded.
Publisher: Royal Society of Chemistry (RSC)
Date: 19-08-2014
DOI: 10.1039/C4CC05545D
Abstract: Lysozyme can be electrochemically detected after adsorption at an electrified gel-water interface. Ex situ characterization by electrostatic spray ionization mass spectrometry provides insights into the interfacial detection mechanism by allowing changes to the tertiary structure of electroadsorbed lysozyme to be fingerprinted for the first time.
Publisher: American Chemical Society (ACS)
Date: 14-02-2012
DOI: 10.1021/AC203249P
Abstract: Electrochemical adsorption and voltammetry of hen-egg-white-lysozyme (HEWL) was studied at an array of microinterfaces between two immiscible electrolyte solutions (μITIES). Adsorption of the protein was achieved at an optimal applied potential of 0.95 V, after which it was desorbed by a voltammetric scan to lower potentials. The voltammetric peak recorded during the desorption scan was dependent on the adsorption time and on the aqueous phase concentration of HEWL. The slow approach to saturation or equilibrium indicated that protein reorganization at the interface was the rate-determining step and not diffusion to the interface. For higher concentrations and longer adsorption times, a HEWL multilayer surface coverage of 550 pmol cm(-2) was formed, on the basis of the assumption that a single monolayer corresponded to a surface coverage of 13 pmol cm(-2). Implementation of adsorption followed by voltammetric detection as an adsorptive stripping voltammetric approach to HEWL detection demonstrated a linear dynamic range of 0.05-1 μM and a limit of detection of 0.03 μM, for 5 min preconcentration in unstirred solution this is a more than 10-fold improvement over previous HEWL detection methods at the ITIES. These results provide the basis for a new analytical approach for label-free protein detection based on adsorptive stripping voltammetry.
Publisher: Elsevier BV
Date: 07-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8NR09195A
Abstract: Multilayer hierarchical electrodes for lithium batteries, made of vertically aligned nanowalls of hematite (Fe 2 O 3 ), alternated with horizontal spacers of reduced graphene oxide (RGO) on a 3D, conductive graphene foam.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7AN00761B
Abstract: The electrochemical behaviour of fucoidan, a sulfated polysaccharide, was investigated, leading to a detection strategy by adsorptive stripping voltammetry.
Publisher: American Chemical Society (ACS)
Date: 08-04-2019
DOI: 10.1021/ACS.LANGMUIR.8B04227
Abstract: The electroadsorption of proteins at aqueous-organic interfaces offers the possibility to examine protein structural rearrangements upon interaction with lipophilic phases, without modifying the bulk protein or relying on a solid support. The aqueous-organic interface has already provided a simple means of electrochemical protein detection, often involving adsorption and ion complexation however, little is yet known about the protein structure at these electrified interfaces. This work focuses on the interaction between proteins and an electrified aqueous-organic interface via controlled protein electroadsorption. Four proteins known to be electroactive at such interfaces were studied: lysozyme, myoglobin, cytochrome c, and hemoglobin. Following controlled protein electroadsorption onto the interface, ex situ structural characterization of the proteins by FTIR spectroscopy was undertaken, focusing on secondary structural traits within the amide I band. The structural variations observed included unfolding to form aggregated antiparallel β-sheets, where the rearrangement was specifically dependent on the interaction with the organic phase. This was supported by MALDI ToF MS measurements, which showed the formation of protein-anion complexes for three of these proteins, and molecular dynamic simulations, which modeled the structure of lysozyme at an aqueous-organic interface. On the basis of these findings, the modulation of protein secondary structure by interfacial electrochemistry opens up unique prospects to selectively modify proteins.
Publisher: Wiley
Date: 24-07-2012
Abstract: Between the phases: The globular protein lysozyme was adsorbed and desorbed under electrochemical conditions at the water/room temperature ionic liquid microinterface array the electrochemical desorption process provides a basis for protein detection at these interfaces.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3AN01123B
Abstract: Electrochemistry at the interface between two immiscible electrolyte solutions (ITIES) provides a platform for label-free detection of biomolecules. In this study, adsorptive stripping voltammetry (AdSV) was implemented at an array of microscale ITIES for the detection of the antidiabetic hormone insulin. By exploiting the potential-controlled adsorption of insulin at the ITIES, insulin was detected at 10 nM via subsequent voltammetric desorption. This is the lowest detected concentration reported to-date for a protein by electrochemistry at the ITIES. Surface coverage calculations indicate that between 0.1 and 1 monolayer of insulin forms at the interface over the 10-1000 nM concentration range of the hormone. In a step toward assessment of selectivity, the optimum adsorption potentials for insulin and albumin were determined to be 0.900 V and 0.975 V, respectively. When present in an aqueous mixture with albumin, insulin was detected by tuning the adsorption potential to 0.9 V, albeit with reduced sensitivity. This provides the first ex le of selective detection of one protein in the presence of another by exploiting optimal adsorption potentials. The results presented here provide a route to the improvement of detection limits and achievement of selectivity for protein detection by electrochemistry at the ITIES.
Publisher: American Chemical Society (ACS)
Date: 18-02-2016
Publisher: Elsevier BV
Date: 02-2022
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/CH15796
Abstract: This review presents an introduction to electrochemistry at interfaces between immiscible electrolyte solutions and surveys recent studies of this form of electrochemistry in electroanalytical strategies. Simple ion and facilitated ion transfers across interfaces varying from millimetre scale to nanometre scales are considered. Target detection strategies for a range of ions, inorganic, organic, and biological, including macromolecules, are discussed.
Publisher: Wiley
Date: 07-06-2013
Abstract: The behavior of proteins and polypeptides at electrified aqueous-organic interfaces is of benefit in label-free detection strategies. In this work, rat amylin (or islet amyloid polypeptide) was studied at the interface formed between aqueous liquid and gelled organic phases. Amylin is a polypeptide that is co-secreted with insulin from islet beta-cells and is implicated in fibril formation. In this study, rat amylin was used, which does not undergo aggregation. The polypeptide underwent an interfacial transfer process, from water to the gelled organic phase, under applied potential stimulation. Cyclic voltammetry revealed steady-state forward and peak-shaped reverse voltammograms, which were consistent with diffusion-controlled water-to-organic transfer and thin-film stripping or desorptive back-transfer. The diffusion-controlled forward current was greater when amylin was present in an acidic aqueous phase than when it was present in an aqueous phase at physiological pH this reflects the greater charge on the polypeptide under acidic conditions. The amylin transfer current was concentration dependent over the range 2-10 μM, at both acidic and physiological pH. At physiological pH, amylin was selectively detected in the presence of a protein mixture, which illustrated the bioanalytical possibilities for this electrochemical behavior.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Wiley
Date: 18-11-2017
Abstract: (Co)Polymers containing pentafluorophenylacetylene (F
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2011
Publisher: Springer Science and Business Media LLC
Date: 14-12-2013
DOI: 10.1007/S00216-012-6622-2
Abstract: The behaviour of haemoglobin (Hb) at the interface between two immiscible electrolyte solutions (ITIES) has been examined for analytical purposes. When Hb is fully protonated under acidic conditions (pH <pI) in the aqueous phase, it undergoes a potential-dependent adsorption and complexation, at the interface, with the anions of the organic phase electrolyte. When utilised as a simple and fast preconcentration step, consisting of adsorbing the protein at the interface, in conjunction with voltammetric desorption, this opens up the ITIES to the adsorptive stripping voltammetry approach. Utilising a 60 s adsorption step and linear sweep voltammetry, a linear response to Hb concentration in aqueous solution over the range 0.01-0.5 μM was achieved. The equation of the best-fit straight line was I(p) = 7.46 C - 0.109, R = 0.996, where I(p) is the peak current (in nano ere) and C is haemoglobin concentration (in micromolar). The calculated detection limit (3σ) was 48 nM for a 60 s preconcentration period, while the relative standard deviation was 13.3% for six successive measurements at 0.1 μM Hb. These results illustrate the prospects for simple, portable and rapid label-free detection of biomacromolecules offered by electrochemistry at arrays of liquid-liquid microinterfaces.
Publisher: Wiley
Date: 15-04-2019
Publisher: Wiley
Date: 26-06-2021
DOI: 10.1002/APP.51314
Abstract: Conducting polymers are promising candidates for wearable devices due to mechanical flexibility combined with electroactivity. While electrochemical measurements have been adopted as a central transduction method in many on‐skin sensors, less studied is the stability of the active materials (in particular poly3,4‐ethylenedioxythiophene, PEDOT) in such systems, particularly for “on‐skin” applications. In this study, several different variants of doped PEDOT are fabricated and characterized in terms of their (electrical, physical, and chemical) stability in biological fluid. PEDOT doped with tosylate (TOS) or polystyrenesulfonate (PSS) are selected as prototypical forms of conducting polymers. These are compared with a new variant of PEDOT co‐doped with both TOS and PSS. Artificial interstitial fluid (aISF) loaded with 1% wt/vol bovine serum albumin is adopted as the testing medium to demonstrate the stability in dermal applications (i.e., conducting polymer microneedles or coatings on microneedles). A range of techniques such as cyclic voltammetry and electrochemical impedance spectroscopy are used to qualify and quantify the stability of the doped conducting polymers. Furthermore, this study is extended by using human skin lysate in the aISF to demonstrate proof‐of‐concept for stable use of PEDOT in wearable “on‐skin” electronics.
Publisher: American Chemical Society (ACS)
Date: 24-10-2021
Publisher: Wiley
Date: 27-02-2017
Publisher: Elsevier BV
Date: 03-2017
Publisher: American Chemical Society (ACS)
Date: 11-08-2020
Start Date: Start date not available
End Date: 2022
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2022
End Date: 08-2023
Amount: $420,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2017
End Date: 12-2023
Amount: $3,708,510.00
Funder: Australian Research Council
View Funded Activity