Antifouling and Antithrombogenic Ultrathin Surface Chemistry for Bioanalytical and Biomedical Applications

Whether the aim is to merely prevent the adsorption and accumulation of biological species, or to inhibit the surface-mediated activation of potentially harmful biological processes, biomaterial research invariably faces the need for man-made, foreign surfaces intimately contacting bodily fluids/tissues to be `bioinert'. A popular strategy to address this technological constraint consists in passivating substrate materials with an antifouling (respectively a biocompatible) organic coating. Yet, despite tremendous research activity and progress in recent times, efficient adlayers are scarce, and endowing artificial surfaces with such properties remains, in essence, a difficult task. This PhD Thesis describes recent research contributions in the development of original and versatile stealth coatings, based on novel oligoethylene glycol trichlorosilane surface chemistry, for bioanalytical and biomedical healthcare applications. Surface modification also has the advantage of being straightforward, rapid and inexpensive.One primary objective was to engineer biosensors capable of selectively and sensitively detecting target analytes in real-world biofluids - exploiting the transducing technology of the ultra-high frequency electromagnetic piezoelectric acoustic sensor (EMPAS) system - as potential clinical assay alternatives to current screening/diagnostic tests. Biosensing platforms featured dual-functional, binary organosilane surface chemistry on quartz combining high analyte binding capability (for biorecognition) with pronounced antifouling properties (to minimize the otherwise overwhelming interference signal from the biological matrix). Clinical testing performance was successfully demonstrated through the detection of bacterial endotoxin - a potent pathogen associated with the highly-incident, deadly condition of sepsis. EMPAS measurements performed in full human blood plasma (and in a real-time and label-free advanced fashion compared to modern clinical assays that rely on chromogenic reporter molecules) showed that samples at abnormally high concentration (1000 pg/mL) can be readily differentiated from those presenting basal endotoxin level (

Department dc:contributor.department

Chemistry

Year dc:date.issued

2014

Author dc:creator

• Sheikh, Sonia

Advisor dc:contributor.advisor

• Michael, Thompson

• Antifouling
• Antithrombogenicity
• Bioanalytical
• Biomedical
• Surface Chemistry

Handle dc:identifier.uri

http://hdl.handle.net/1807/68325

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/68325