Chemistry Seminar: Anti-Fouling Acoustic Wave & Electrochemical Biosensor Technology

Thursday, January 18, 2018

11:00 AM-12:00 PM

Michael Thompson , PhD, University of Toronto

 

“Anti-Fouling Acoustic Wave & Electrochemical Biosensor Technology”

Our research concerns the development of a chemipassive surface that is being employed to modify both the surface of biosensors and other devices used in medicine. The interaction of substrates with the components of biological fluids, especially blood, has constituted a research problem over many years. In this regard, a variety of strategies have been used to attempt an enhancement of biocompatibility with some emphasis being centered on the imposition of a plethora of surface coatings. In our work we are addressing the physical chemistry of covalent surface modification through the synthesis of new silane-based molecules. These moieties are bifunctional, medium-chain length trichlorosilanes containing a PEG backbone. (PEG has been the subject of intense study for many years). Given that strategies for enhanced biocompatibility and anti-fouling of biosensors share much common ground, we applied our surface modification in both fields. In particular, we have applied the anti-fouling approach to the acoustic wave detection of endotoxin in human plasma and cancer biomarkers in serum, and K+ concentration in brain-based fluid. With regard to the former, a qualitative, cut-off (mid pg per mL) biosensor assay alternative for bacterial endotoxin has been developed based on the acoustic wave physics of the highly sensitive, ultra-high frequency electromagnetic piezoelectric acoustic sensor (EMPAS) transducing device. Secondly, in collaboration with Electrical Engineering at the University of Toronto and the Krembil Institute (Western Hospital) Toronto we have fabricated a multichannel monolayer coated gold microelectrode for in vivo spatio-temporal measurements of [K+]o in a mouse brain as an improvement to the more conventional glass capillary electrode. The performance of the device is critically dependent on the aforementioned anti-fouling surface modification used in tandem with a new probe for potassium. Finally we are now employing the anti-fouling chemistry in a search for an assay for the early stage detection of ovarian cancer. This is based on biosensor detection of two biomarkers for the disease directly in human serum, HSP10 and lysophosphatidic acid.

Contact Information

Haifeng (Frank) Ji
215.895.2562
hj56@drexel.edu