(398d) Electrophoresis and Electroomosis in Planar Nanofluidic Channels

Electrokinetic based micro- and nanofluidic technologies provide revolutionary opportunities to separate, identify and analyze biomolecular species. In this talk, I will present results from joint theoretical and experimental studies of electroomosis and electrophoresis in planar nanofluidic channels. Key to fully harnessing the power of such systems is a thorough understanding of the influence of the electrokinetic surface properties. Therefore, I will also present results from investigations of electrokinetic surface properties in nano- and microfluidic channels fabricated with fused silica, insulated metals, and/or polymeric material. Specifically, I will describe techniques used to measure such electrokinetic properties within experimental micro- and nanofluidic systems, including the solution displacement method of current monitoring and electrokinetic injection techniques. Next, I will describe a models developed to find surface properties using this technique, and three separate experimental validations of this electrokinetic surface model, one using capillary filling, one with electrokinetic flow, and one using pressure driven flows. Finally, I will describe the latest results of electrophoretic separations in a nanofluidic channel with both small ions and short oligonucleotides, using combined electroomossis and pressure driven flow. These latest investigations uncover how to not only achieve infinite retention of ionic species using nanofluidics, but also how such channels can elucidate more information about the analyte of interest than conventional electrophoretic separation techniques.