Evaluation of nanopores as candidates for electronic analyte detection



In an effort to increase throughput and decrease the cost of electrophoretic separation of DNA and proteins, various groups are developing highly parallel, miniaturized separation devices based on capillaries etched into silicon, glass or plastic substrates. To date, these miniaturized devices have relied on optical detectors, thus placing a lower limit on instrument size, and complicating the incorporation of an entire DNA analyzer instrument on a chip. To address this limitation, we are evaluating nanopores as candidate Coulter counters for purely electronic detection of analytes in miniaturized electrophoresis and similar separation devices. To establish feasibility of this detection scheme, we have investigated the detection sensitivity of a nanopore sensor through experiments with the α-hemolysin (α-HL) ion channel, and through a Monte Carlo (MC) model of polymer capture rate with a cylindrical nanopore under an applied voltage. Experimental and model results are extrapolated to predict the capture rate of synthetic pores operating at higher voltages than presently achievable with protein pores.