(415b) Multiple Measurements On Single DNA Molecules in Nanopore Sensors

There is a significant gap in technology for rapid, label-free characterization of single molecules and particles in the submicrometer size range. Advances in nanotechnology have resulted in nanoscale Coulter counters and nanopores that can size single molecules and particles using transient current changes during translocation through the nanopore. The sensing ability of nanopores is often limited by the quick transit times of molecules through the nanopore that results in poor signal-to-noise ratio. To address this issue, we fabricated a nanopore device and implemented feedback control to recapture DNA back into the nanopore, yielding multiple measurements and enabling statistical averaging on the same molecule. With the implementation, we demonstrated that different DNA molecules that have slight differences in magnitude of current changes could be differentiated in our nanofluidic system. This approach may lead to nanopore devices with enhanced sensitivity for analysis of single molecules and particles.