Development of Paper-based Devices for Diagnostics and Biosensing

Abstract

<p>Research in paper-based analytical devices has been increasing rapidly in recent years. Manyof these devices are used as low-cost alternatives for diagnostics and biosensing. In this work,two novel paper-based technologies were developed.</p> <p>The first paper-based technology achieved was measuring streaming potential on paper-based microfluidic devices. The streaming potential measurements were able to detect the presence of adsorbed polyvinylamine or potassium polyvinylsulfate in paper-based microfluidic channels.</p> <p>The measured streaming potential ranged from -80 mV to 80 mV and the polarity was sensitive to the adsorbed polymer. Furthermore, the measured streaming potential on paper treated with BSA showed a polarity switch when the pH was changed from below the pKa to above the pKa of BSA. Lastly, streaming potential measurements may provide an electronic interface for paperbased sensors.</p> <p>The second technology developed was a paper-based chromatographic pre-concentration device for biological and chemical applications. The device successfully concentrated a protein, streptavidin, via biotinylated microgels immobilized onto a selected area of the filter paper. The device was able to process a large volume of fluid with the incorporation of a passive pump made of superabsorbent polymer. The concentration factor achieved by the device was over 3000-fold. The flow dynamics through the paper was modeled using Darcy’s law. This technology could be an excellent low-cost alternative for biochemical analysis for samples thatrequire preconcentration, especially for the analysis of trace compounds in wastewater and drinking water.</p>