Biosensor and microfluidic technologies based on bead packed microcolumns

Development of new rapid and high throughput bioanalytical technologies will always be beneficial for different fields and applications including biotechnology and clinical studies. The aim of this study is to develop bead packed microcolumns for miniaturized chemical sensors and sample delivery methods for microfluidic applications. We investigate feasibility of the use of bead packed microcolumns as microfluidic components that are the basis of rapid mixing, high surface area receptor scaffolds and high pressure electroosmotic pumps.; Rapid mixing and reaction are needed for many microfluidic assays. In microdevices, mixing of compounds is limited by diffusion, which can be a slow process especially for large biomolecules. In one study of this dissertation, we have investigated new methods to generate fast mixing in microfluidic devices.; In another study a microfluidic biosensor is successfully developed to detect multiple analytes in near simultaneous fashion. Biologically and clinically important compounds have been effectively analyzed utilizing microchannels packed with bio-functionalized receptor beads and fluorescence spectroscopy. Further a biosensing concept based on phospholipid bilayer disruption and controlled release of encapsulated compounds has been introduced. Bilayer coated porous silica beads have been demonstrated as a stable new encapsulation media.; Finally, a miniaturized electroosmotic fluidic pump has been designed and fabricated for microfluidic applications. High pressures were generated by applying an electric field across a micro-capillary packed with silica beads. An analytical model has been introduced to allow optimization of the pressure generation and flow rate in the pumps.