ORCID Profile
0000-0002-9702-8653
Current Organisation
University of New South Wales - Randwick Campus
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Publisher: Elsevier BV
Date: 06-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0CC02690E
Abstract: Herein, we introduce the concept of utilizing conductive gold-coated magnetic nanoparticles as 'dispersible electrodes', which serve as the active element in the selective capture and direct electro-analytical quantification of analytes. This concept reduces response times and decreases detection limits by bringing the sensor to the analyte rather than the conventional paradigm of the analyte finding the sensor.
Publisher: Wiley
Date: 25-05-2012
Abstract: New sensation: A resistance-based biosensor uses gold-coated magnetic nanoparticles (Au@MNPs) functionalized with the antibiotic enrofloxin (see picture purple), which bind to anti-enrofloxin as analyte (blue). The Au@MNPs can be magnetically assembled between electrodes, and the measured resistance R is a function of analyte concentration.
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.JCIS.2010.10.061
Abstract: The effect of gold attachment on the physical characteristics, cellular uptake, gene expression efficiency, and biocompatibility of magnetic iron oxide (MNP) vector was investigated in vitro in BHK21 cells. The surface modification of magnetite with gold was shown to alter the morphology and surface charge of the vector. Nonetheless, despite the differences in the surface charge with and without gold attachment, the surface charge of all vectors were positive when conjugated with PEI/DNA complex, and switched from positive to negative when suspended in cell media containing serum, indicating the adsorption of serum components onto the composite. The cellular uptake of all MNP vectors under the influence of a magnetic field increased when the composite loadings increased, and was higher for the MNP vector that was modified with gold. Both bare magnetite and gold-coated magnetite vectors gave similar optimal gene expression efficiency, however, the gold-coated magnetite vector required a 25-fold higher overall loading to achieve a comparable efficiency as the attachment of gold increased the particle size, thus reducing the surface area for PEI/DNA complex conjugation. The MNP vector without gold showed optimal gene expression efficiency at a specific magnetite loading, however further increases beyond the optimum loading decreased the efficiency of gene expression. The drop in efficiency at high magnetite loadings was attributed to the significant reduction in cellular viability, indicating the bare magnetite became toxic at high intracellular levels. The gene expression efficiency of the gold-modified vector, on the other hand, did not diminish with increasing magnetite loadings. Intracellular examination of both bare magnetite and gold-coated magnetite vectors at 48h post-magnetofection using transmission electron microscopy provided evidence of the localization of both vectors in the cell nucleus for gene expression and elucidated the nuclear uptake mechanism of both vectors. The results of this work demonstrate the efficacy of gold-modified vectors to be used in cellular therapy research that can function both as a magnetically-driven gene delivery vehicle and an intracellular imaging agent with negligible impact on cell viability.
Publisher: American Chemical Society (ACS)
Date: 22-01-2009
DOI: 10.1021/CM8025329
Publisher: European Respiratory Society (ERS)
Date: 26-07-2022
DOI: 10.1183/13993003.02962-2021
Abstract: There are few data to support accurate interpretation of spirometry data in South Asia, a major global region with a high reported burden of chronic respiratory disease. We measured lung function in 7453 healthy men and women aged ≥18 years, from Bangladesh, North India, South India, Pakistan and Sri Lanka, as part of the South Asia Biobank study. First, we assessed the accuracy of existing equations for predicting normal forced vital capacity (FVC), forced expiratory volume in 1 s (FEV 1 ) and FEV 1 /FVC ratio. Then, we used our data to derive (n=5589) and internally validate (n=1864) new prediction equations among South Asians, with further external validation among 339 healthy South Asians living in Singapore. The Global Lung Initiative (GLI) and National Health and Nutrition Examination Survey consistently overestimated expiratory volumes (best fit GLI-African American, mean± sd z-score: FEV 1 −0.94±1.05, FVC −0.91±1.10 n=7453). Age, height and weight were strong predictors of lung function in our participants (p .001), and sex-specific reference equations using these three variables were highly accurate in both internal validation (z-scores: FEV 1 0.03±0.99, FVC 0.04±0.97, FEV 1 /FVC −0.03±0.99) and external validation (z-scores: FEV 1 0.31±0.99, FVC 0.24±0.97, FEV 1 /FVC 0.16±0.91). Further adjustment for study regions improves the model fit, with highest accuracy for estimation of region-specific lung function in South Asia. We present improved equations for predicting lung function in South Asians. These offer the opportunity to enhance diagnosis and management of acute and chronic lung diseases in this major global population.
Publisher: Wiley
Date: 06-09-2010
Abstract: Physical and electrochemical properties of gold nanoparticle-based electrodes are highlighted. Polycrystalline gold electrodes are passivated by a self-assembled monolayer, then the immobilization of gold nanoparticles "switch on" the electrochemical reactivity of ruthenium. Herein, gap-mode Raman studies show that the location of the nanoparticles is on the top of the monolayer, meaning that the "switching on" cannot be attributed to a direct electrical contact between nanoparticles and the gold support. This "switching on" feature is also not affected by the size of the gold nanoparticles with a range of diameters between 4 and 67 nm. Further, the charge of the nanoparticles is investigated by grafting chemical groups onto the nanoparticles which is observed to alter the electron-transfer kinetics. The variation in rate constant however is insufficient to attribute the "switching on" phenomenon to a possible adsorption of the redox species onto the nanoparticles.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC30512G
Publisher: American Chemical Society (ACS)
Date: 08-06-2010
DOI: 10.1021/LA101196R
Abstract: Presented herein is a detailed study into the controlled adsorption of polyethylenimine (PEI) onto 50 nm crystalline magnetite nanoparticles (Fe(3)O(4) NPs) and how these PEI-coated Fe(3)O(4) NPs can be used for the magnetic capture and quantification of ultratrace levels of free cupric ions. We show the ability to systematically control the amount of PEI adsorbed onto the Fe(3)O(4) magnetic nanoparticle surfaces by varying the concentration of polymer during the adsorption process. This in turn allows for the tailoring of important colloidal properties such as the electrophoretic mobility and aggregation stability. Copper adsorption tests were carried out to investigate the effectiveness of PEI-coated Fe(3)O(4) NPs in copper remediation and detection. The study demonstrated that the NPs ability to bind with copper is highly dependent on the amount of PEI adsorbed on the NP surface. It was found that PEI-coated Fe(3)O(4) NPs were able to capture trace levels (approximately 2 ppb) of free cupric ions and concentrate the ions to allow for detection via ICP-OES. More importantly, it was found that due to the amine-rich structure of PEI, the PEI-coated Fe(3)O(4) NPs selectively adsorb toxic free cupric ions but not the less toxic EDTA complexed copper. This unique property makes PEI-coated Fe(3)O(4) NPs a novel solution for the challenge of separating and quantifying toxic cupric ions as opposed to the total copper concentration of a s le.
Publisher: Elsevier BV
Date: 03-2021
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Ian Y. Goon.