Planar Capillary Electrophoresis

University Of Kansas Center For Research Inc, Lawrence KS

Investigators

Abstract

With support from the Chemical Measurement and Imaging (CMI) Program in the Division of Chemistry (CHE) and co-funding from the Established Program to Stimulate Competitive Research (EPSCoR), Professor Robert Dunn and his group at the University of Kansas are developing innovative, cost-effective approaches for rapidly analyzing complex mixtures. Mixtures such as blood and urine contain thousands of molecules that reflect the normal functions taking place within the human body. Hidden within these complicated fluids can be molecular clues about diseases or disorders, that if detected early can aid in their treatment. Dr. Dunn and his group are developing new approaches to rapidly detect these molecules by separating mixtures through small capillaries that are as thin as a human hair. The thin wall of the capillary enables unique control over fundamental separation parameters which will be developed to enhance detection. The research plan combines fundamental studies with applied measurements and elements of engineering, thus exposing students to a highly interdisciplinary and collaborative research environment. Combined with a novel sample droplet delivery system, the fully integrated analysis platform has the potential to provide significant new capabilities for separations science. This research project will train undergraduate and graduate students in a highly collaborative and interdisciplinary environment, leading to enhanced opportunities for professional development. Planar capillary electrophoresis (PCE) uses a short length capillary to rapidly separate and detect species in complex mixtures. The PCE uses a 10 cm total length capillary (50 um i.d. x 80 um o.d.) with an ultra-thin capillary wall (15 um) that efficiently dissipates heat and mitigates the effects of Joule heating. The utiization of an ultra-thin wall provides particular opportunities for developing new approaches and probing fundamental processes. For example, it facilitates the use of an externally applied field to modify the zeta potential and control electroosmotic flow (EOF). This allows facile control of the EOF and leads to a significant increase in peak efficiency. The mechanism for the latter will be fully explored through experiment and simulation and optimized to improve performance. The thin capillaries are also highly flexible, enabling looped geometries that bring the separation path across the detection zone multiple times. This will be developed for kinetic studies of ligand-binding. Finally, the small capillary diameter will enable coupling with digital microfluidics (DMF) to develop fully integrated analysis and economical platforms that have great potential in terms of versatility. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.