In this work, we present two different applications of microfluidic control. In the first application, we have developed a microfluidic device that has the potential to automate combinatorial protocols like protein refolding, impacting the biopharmaceutical industry. This device uses microfluidic valves and pumps that can be operated in an automated fashion for fluidic control. We performed refolding experiments on the protein [beta]-galactosidase and showed on-chip quantification of refolding yield using a fluorometric assay. In the second application, we have developed a microfluidic immunobiosensor with an integrated preconcentration system to improve the detection sensitivity. A nanoporous membrane fabricated in-situ using photopolymerization technique inside glass microchannels acts as the preconcentration system. Analytes were electrophoretically concentrated at the membrane and the concentrated bolus was eluted towards a detection region downstream. We performed proof-of-principle experiments using biotin-streptavidin binding to show the improvement in detection sensitivity of this device as opposed to a device that does not include a preconcentration system. Using this device, we also showed a detection limit of 1.6 X 105 PFU/ml for Feline Calicivirus (FCV), which is a model system for human enteric virus. This device has potential to serve as an early detection system for such enteric viruses in environmental water samples.