Microfluidics and Permselective Membranes for Biosensors

This dissertation presents the approaches to realize Point-of-Care devices for cancer detection and studying permselective polymeric membranes for implantable glucose sensors. For the former project, aiming to realize affordable, portable, and reliable devices for cancer detection, we successfully obtained micron- to nanosized patterns such as nanosized array electrodes; high resolution, custom-made chromium photomasks; micron-sized filters with high aspect ratio, at low cost and ease of fabrication by utilizing edge patterning methods. The integrated microfluidic devices with nanowire arrays and micro-pillar filtration can greatly increase the sensitivity and enhance automation in immunoassay devices. This study also developed the immunoassay utilizing both 1 µm and 6 µm beads, which were able to implemented into microfluidic platforms and improve detection limits of the immunoassays. Regarding to the second project, in order to significantly increase the selectivity at least expense of sensitivity of implantable glucose sensors, different polymeric materials deposited on electrode surfaces have been investigated. The results showed that electropolymerized poly(flavin mononucleotide) on electrode surfaces are able to reject endogenous interferences while the permeability to hydrogen peroxide is as high as bare Pt electrodes. In addition, electro-copolymerization of FMN and phenol films are the promising materials to realize the biosensors having both good selectivity and sensitivit