Proposed is the additional development of a new technique for microfluidic separations called traveling-wave electrophoresis (TWE). This technique employs an electric field wave produced by interdigitated electrode arrays to transport charged species through a microchannel. To investigate approaches for efficient separations of complex mixtures of peptides and other biomolecular systems, the proposed research will focus on two aims: (a) establishing the dependence of band dispersion on molecular concentration, electrophoretic mobility, and molecular diffusion in TWE, and (b) demonstrating TWE separations of complex mixtures of peptides using novel separation modes accessible through TWE. These experimental aims will synergistically interact with theoretical modeling of the TWE system to understand the fundamental capabilities and limits of the process. The proposed goals will be accomplished through experiments and modeling stemming from preliminary models and experiments that have unequivocally demonstrated the feasibility of the technique.
The proposed research addresses the critical need for robust, controllable, on-demand separation techniques for high-resolution, high-throughput characterization of complex biomolecular samples. TWE separations distinguish themselves from other electrophoretic microfluidic separation techniques by the use of an electric wave to transport species whose mobilities exceed a tunable threshold. TWE holds promise for separations with minimal dispersion and separations of infinite length achieved via real-time switching between separative and non-separative transport, allowing extremely high resolution separations of closely migrating analytes. The impact of this work will be felt in proteomics, molecular biology, cell biology, genetics, materials synthesis, and nanoscience. The system has the potential to make particularly strong contributions to proteomics and molecular biology based on its capability to separate closely related molecular species present in vastly different concentrations. The ability to independently control the velocities of separated bands in a single channel based on their local position without sacrificing separation efficiency will prove to be revolutionary if realized.
The broader impacts of this work consist of five major areas. Of particular importance in the state of West Virginia is the incorporation of a Research Experience for Teachers. We will incorporate secondary school teachers into the research program, providing opportunities for professional development credits, and developing curricular elements meeting state guidelines for incorporation into their classrooms. The program will extend beyond the summer with the PIs interacting with the teachers and their students in the classroom, and providing opportunities for participating teachers to present their research and curricular efforts in both local and national settings. The PIs are actively involved in the development of undergraduate and graduate course work that emphasizes the importance of nanoscience and nanotechnology, both in science and in society at large. These courses reach students across different disciplines in the physical sciences, engineering, biomedicine, and the humanities and provide a common forum to facilitate cross-pollination of ideas within the university. The project will provide funding for two graduate students, one theoretical and one experimental. Work on this project will promote interdisciplinary interactions between developing physicists and chemists during their training, a very important benefit in this era of multi-disciplinary research. Outreach to underrepresented groups will be accomplished in summer research experiences for undergraduates through existing SURE, REU, and LSAMP programs. In addition, ongoing relationships with a local company, Protea, Inc. will allow immediate incorporation of research innovations in the development of commercial products for protein analysis.
