ORCID Profile
0000-0003-0377-6069
Current Organisation
Trajan Scientific Switzerland
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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.
Analytical Chemistry | Separation Science | Sensor Technology (Chemical aspects) | Manufacturing Processes and Technologies (excl. Textiles)
Expanding Knowledge in the Chemical Sciences | Scientific Instruments |
Publisher: American Chemical Society (ACS)
Date: 06-12-2017
DOI: 10.1021/ACS.LANGMUIR.7B02825
Abstract: Capillary action is one mechanism microfluidics uses to draw liquid autonomously in a substrate without the need of external energy. This behavior can be exploited to collect accurate volumes of liquids such as blood in narrow columns known as capillary tubes and help the development of inexpensive, user-friendly personalized biomedical tools. Precision bore glass capillaries demonstrate the "state of the art" for volume accuracy and precision, but height and radius must be carefully chosen in order to exploit the capillary action behavior efficiently. This Article investigates the influence of surface glass aging, due to prolonged exposure to humid air, and hematocrit level on the blood capillary rise. It provides also the tools to correctly define the optimum capillary dimensions to collect an accurate volume of blood in a glass capillary tube.
Publisher: Future Science Ltd
Date: 08-2021
Abstract: Aim: Serological assays for the detection of anti-SARS coronavirus-2 (SARS-CoV-2) antibodies are essential to the response to the global pandemic. A ligand binding-based serological assay was validated for the semiquantitative detection of IgG, IgM, IgA and neutralizing antibodies (nAb) against SARS-CoV-2 in serum. Results: The assay demonstrated high levels of diagnostic specificity and sensitivity (85–99% for all analytes). Serum IgG, IgM, IgA and nAb correlated positively (R 2 = 0.937, R 2 = 0.839, R 2 = 0.939 and R 2 = 0.501, p 0.001, respectively) with those measured in dried blood spot s les collected using the hemaPEN ® micros ling device (Trajan Scientific and Medical, Victoria, Australia). In vitro SARS-CoV-2 pseudotype neutralization correlated positively with the solid phase nAb signals in convalescent donors (R 2 = 0.458, p 0.05). Conclusion: The assay is applicable in efficacy studies, infection monitoring and postmarketing surveillance following vaccine rollout.
Publisher: SPIE
Date: 21-12-2011
DOI: 10.1117/12.903271
Publisher: Future Science Ltd
Date: 12-2020
Abstract: Background: The hemaPEN is a liquid micros ling device for the reproducible collection and storage of blood s les as dried blood spots, for subsequent quantitative analysis. Materials & methods: We examined the device’s ability to collect accurate and precise blood volumes, at different hematocrit levels, via in vitro studies using acetaminophen in human blood. We also investigated the impact of different user training approaches on device performance. Results: The hemaPEN demonstrated acceptable volumetric accuracy and precision, regardless of the training medium used. Issues with apparent hematocrit-dependent bias were found to be associated with the extraction process, rather than the volumetric performance of the device. Conclusion: The hemaPEN is capable of readily producing high quality blood micros les for reproducible and accurate quantitative bioanalysis.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4LC00650J
Abstract: How to take advantage of superhydrophobic microgrids to address the problem of coupling continuous to digital microfluidic systems? A reconfigurable capillary connection for digital microfluidic devices is presented.
Publisher: Springer International Publishing
Date: 2015
Publisher: Springer Science and Business Media LLC
Date: 15-02-2013
Publisher: Springer New York
Date: 2015
Publisher: IEEE
Date: 2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B925544C
Abstract: The reversible actuation of droplets on superhydrophobic surfaces under ambient conditions is currently an important field of research due to its potential applicability in microfluidic lab-on-a-chip devices. We have recently shown that Si-nanowire (NW) surfaces allow for reversible actuation provided that the surface structures show certain characteristics. In particular it appears that, for such surfaces, the presence of structures with multiple specific length scales is indeed needed to have a robust reversibility of contact angle changes. Here we report on electrowetting (EW) and impalement experiments on double-scale structured surfaces prepared by a combination of silicon micropillars prepared by an association of optical lithography and silicon etching, and nanowire growth on top of these surfaces. We show that while micropillar surfaces have a low impalement threshold and irreversible EW behaviour, a surface with double-scale texture can show both a very high resistance to impalement and a limited reversibility under EW, provided that the roughness of the micro-scale is large enough--i.e. that the pillars are tall enough. The optimal performance is obtained for a space between pillars that is comparable to the height of the nanostructure.
Publisher: AIP Publishing
Date: 21-12-2009
DOI: 10.1063/1.3275709
Abstract: We report on experiments of drop impacting a hydrophobic microgrid of typical spacing a few tens of micrometers. Above a threshold in impact speed, liquid emerges to the other side, forming microdroplets of size about that of the grid holes. We propose a method to produce either a monodisperse spray or a single tiny droplet of volume as small as a few picolitres corresponding to a volume ision of the liquid drop by a factor of up to 105. We also discuss the discrepancy of the measured thresholds with that predicted by a balance between inertia and capillarity.
Publisher: American Chemical Society (ACS)
Date: 27-08-2008
DOI: 10.1021/LA801268V
Abstract: The paper reports on the comparison of the wetting properties of superhydrophobic silicon nanowires (NWs), using drop impact impalement and electrowetting (EW) experiments. A correlation between the resistance to impalement on both EW and drop impact is shown. From the results, it is evident that when increasing the length and density of NWs (i) the thresholds for drop impact and EW irreversibility increase and (ii) the contact-angle hysteresis after impalement decreases. This suggests that the structure of the NW network could allow for partial impalement, hence preserving the reversibility, and that EW acts the same way as an external pressure. The most robust of our surfaces shows a threshold to impalement higher than 35 kPa, while most of the superhydrophobic surfaces tested so far have impalement thresholds smaller than 10 kPa.
Publisher: SPIE
Date: 13-03-2015
DOI: 10.1117/12.2082601
Publisher: Wiley
Date: 24-01-2014
DOI: 10.1002/APP.40416
Publisher: Springer Science and Business Media LLC
Date: 30-04-2018
Publisher: IOP Publishing
Date: 04-02-2015
Publisher: American Chemical Society (ACS)
Date: 24-10-2013
DOI: 10.1021/LA4026848
Abstract: Usually, electrowetting on superhydrophobic surfaces (EWOSS) is generated by application of an alternating current signal and often leads to droplet impalement into the structuration. To avoid this phenomenon, superhydrophobic surfaces must show robustness to high pressure. Otherwise, an external energy has to be applied to dewet the droplet from the structuration. We present, in this article, an original approach to actuate liquid droplets via a modulated EWOSS signal (MEWOSS). This technique allows the dewetting of the droplet due to periodic vibrations induced by the electrowetting actuation. In that case, it is possible to investigate a larger range of superhydrophobic surfaces under EWOSS without droplet impalement. Three different superhydrophobic surfaces, showing different degrees of impalement under EWOSS, are investigated and compared using this MEWOSS technique.
Publisher: Springer Science and Business Media LLC
Date: 05-04-2018
DOI: 10.1007/S00216-018-0993-Y
Abstract: An accurate and precise 3 μL blood collection and dispensing system is presented for the preparation of dried blood spot (DBS) s les. Using end-to-end glass capillaries in conjugation with pre-punched DBS pads, a blood micro collection system was developed to eliminate the haematocrit dispersion, widely associated with DBS technology, while providing better levels of accuracy and precision during s le preparation. This methodology is compared to traditional micro-volume blood collection systems, such as a pipette and a digitally controlled analytical syringe. Results showed that % of recovery for the capillary methodology was closer to 100% across the three haematocrit (HCT) levels tested and when prepared by two users (98 to 100% for capillaries, 78 to 104% for pipette and 93 to 97% for digital syringe) attesting a higher accuracy. Additionally, by taking advantage of the capillary action mechanism to collect and dispense autonomously the desired volume of blood onto the DBS pad, coefficients of variation between two in iduals were significantly lower than with standard methodologies (capillaries-0.05 to 0.77%, pipette-12.71 to 18.53% and digital syringe-0.72 to 1.77%). This alternate aspiration and dispensing methodology could be used by different users without compromising accuracy or precision when handling low volumes of blood during the pre-analytical steps. Graphical abstract Comparison of novel capillary dispensing methodology for dried blood spot s le preparation with pipette and digital syringe methodologies through accuracy and precision measurements of caffeine.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2TC00241H
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0LC00203H
Abstract: Environmental air monitoring is of great interest due to the large number of people concerned and exposed to different possible risks. From the most common particles in our environment (e.g. by-products of combustion or pollens) to more specific and dangerous agents (e.g. pathogenic micro-organisms), there are a large range of particles that need to be controlled. In this article we propose an original study on the collection of electrostatically deposited particles using electrowetting droplet displacement. A variety of particles were studied, from synthetic particles (e.g. Polystyrene Latex (PSL) microsphere) to different classes of biological particle (proteins, bacterial spores and a viral simulant). Furthermore, we have compared ElectroWetting-On-Dielectric (EWOD) collecting efficiency using either a hydrophobic or a superhydrophobic counter electrode. We observe different cleaning efficiencies, depending on the hydrophobicity of the substrate (varying from 45% to 99%). Superhydrophobic surfaces show the best cleaning efficiency with water droplets for all investigated particles (MS2 bacteriophage, BG (Bacillus atrophaeus) spores, OA (ovalbumin) proteins, and PSL).
Publisher: American Chemical Society (ACS)
Date: 03-02-2009
DOI: 10.1021/LA900144D
Publisher: Springer US
Date: 2014
Publisher: The Optical Society
Date: 04-03-2015
DOI: 10.1364/OE.23.006763
Publisher: SPIE
Date: 07-12-2013
DOI: 10.1117/12.2033569
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.JVIROMET.2015.05.008
Abstract: Detection of Hendra viral IgG antibody in animal sera is useful for surveillance following a virus outbreak. The commonly used enzyme-linked immunosorbent assay and fluorescence-based Luminex assay typically consist of three steps and take at least several hours to complete. We have simplified the procedure to two steps in an effort to develop a rapid procedure for IgG antibody, but not IgM antibody, detection. This is achieved by conjugating the fluorescence label R-phycoerythrin directly onto the IgG binding protein Protein G. The use of magnetic nanoparticles, due to their large specific surface area, has helped reduce each of the binding steps to 20 min. As a result, the whole assay can be completed in 60 min. We also demonstrate a method to quickly estimate IgG antibody titres by assaying the sera at only two dilutions (i.e. 1:20 and 1:1000) and using the fluorescence ratio at these dilutions as an indicator of antibody titre. The results of this approach correlated well with the well-regarded serum neutralization test in virus antibody assays. This protocol reported here can be adopted in Luminex assays, fluorescence-linked immunosorbent assays and assays on microfluidics platforms for rapid antibody surveillance of Hendra and other viruses.
Publisher: American Chemical Society (ACS)
Date: 29-04-2009
DOI: 10.1021/LA803756F
Abstract: The paper reports on wetting, electrowetting (EW), and systematic contact angle hysteresis measurements after electrowetting of superhydrophobic silicon nanowire surfaces (NWs). The surfaces consist of C4F8-coated silicon nanowires grown on Si/SiO2 substrate. Different surfaces modulating (i) the dielectric layer thickness and (ii) the nanotexturation were investigated in this study. It was found that the superhydrophobic NWs display different EW behaviors according to their double nanotexturation with varying droplet impalement levels. Some surfaces exhibited a total reversibility to EW with no impalement (contact angle variation of 35+/-2 degrees at 190 VTRMS with deionized water), whereas other surfaces showed nonreversible behavior to EW with partial droplet impalement. A scenario is proposed to explain the unique properties of these surfaces.
Publisher: IEEE
Date: 06-2011
Publisher: SPIE
Date: 07-12-2013
DOI: 10.1117/12.2033508
Start Date: 10-2014
End Date: 06-2019
Amount: $2,148,935.00
Funder: Australian Research Council
View Funded Activity