RESEARCH OVERVIEW:
The surface science of bioassay devices group is a newly formed BDI research programme since Autumn 2008. Point of Care diagnostic devices often have to measure biomolecule concentrations at the picomolar level in blood sample volumes on the microliter scale, without the possibility of any user manipulation of the sample. This is exceptionally challenging to achieve in a miniature bioassay device. Activity of surface –bound antibody and non-specific binding of background proteins limit the sensitivity of a bioassay device.

The research approach of the bioassay group is to develop measurement tools, synthetic approaches and theory that will enable us to build a fundamental understanding of the interaction forces in real systems, and how these relate on the one hand to the surface composition and chemistry, and on the other hand to the specificity, sensitivity and resistance to NSB. The model systems used will be direct sandwich fluoro-immunoassays and particle-capture assays on zeonor substrates.

Key programme elements:

• Total internal reflection spectroscopic ellipsometry - a method that sensitively measures the non-specific binding of proteins, including the signal antibody in the absence of antigen
• TIRF microscopy with image capture and processing to measure directly the collision frequency of label particles with the capture surface and their residence time
• Dynamic light scattering measurement of reaction-limited aggregation measures the surface reactivity of particles
• AFM measurement of force-separation distance curves, for interaction of a modified tip with a prepared surface. These forces can be related to measured variations in particle capture rate and non-specific binding

SELECTED PUBLICATIONS:

• Gandhiraman, R.P., Volcke, C., Gubala, V., Doyle, C., Basabe-Desmonts, L., Dotzler, C., Toney, M.F., Iacono, M., Nooney, R.I., Daniels, S., James, B., Williams, D.E. (Accepted) High Efficiency Amine Functionalization of Cyclo Olefin Polymer Surfaces for Biodiagnostics. Journal of Materials Chemistry.

• Volcke, C., Gandhiraman, R.P., Gubala, V., Raj, J., Cummins, T., Fonder, G., Nooney, R.I., Mekhalif, Z., Herzog, G., Daniels., Arrigan, D.W.M., Cafolla, A.A.. & Williams, D.E. (In press) Reactive amine surfaces for biosensor applications, prepared by plasma-enhanced chemical vapour modification of polyolefin materials. Biosensors & Bioelectronics.

• Volcke, C., Gandhiraman, R.P., Basabe-Desmonts, L., Iacono, M., Gubala, V., Cecchet, F., Cafolla, A.A.. & Williams, D.E. (2010) Protein pattern transfer for biosensor applications. Biosensors and Bioelectronics, 25 (6), 1295-1300. (February)

INTELLECTUAL PROPERTY:

• Intellectual Property information is available here.

 

 

 

PRINCIPAL INVESTIGATOR:
Prof. David E Williams

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Professor David E Williams is a graduate of the University of Auckland, New Zealand. He developed his research career in electrochemistry and chemical sensors at the UK Atomic Energy Research Establishment, Harwell, in the 1980s.

He became Thomas Graham Professor of Chemistry at University College London in 1991 and co-founded Capteur Sensors Ltd. He was Head of the Chemistry Dept at UCL from 1999-2002 and co-founded Aeroqual Ltd (www.aeroqual.com). He was Chief Scientist of Inverness Medical Innovations ( www.invernessmedical.com ), based at Unipath Ltd, Bedford, UK, from 2002-2005. He joined the faculty of the Chemistry Dept at Auckland University in February 2006. He is a Science Foundation Ireland Walton Visitor to the Biomedical Diagnostics Institute, Dublin City University. He is a Visiting Professor at University College London, where he has strong research links, and University of Southampton, and Honorary Professor of the Royal Institution of Great Britain, and has been Visiting Professor at University of Toronto and Cranfield University of Technology.

He has published around 200 papers in international journals, and is inventor on around 40 patents.

www.che.auckland.ac.nz