Local electrical potential detection of DNA by nanowire-nanopore sensors

Nanopores could potentially be used to perform single-molecule DNA sequencing at low cost and with high throughput(1-4). Although single base resolution and differentiation have been demonstrated with nanopores using ionic current measurements(5-7), direct sequencing has not been achieved because of the difficulties in recording very small (similar to pA) ionic currents at a bandwidth consistent with fast translocation speeds(1-3). Here, we show that solid-state nanopores can be combined with silicon nanowire field-effect transistors to create sensors in which detection is localized and self-aligned at the nanopore. Well-defined field-effect transistor signals associated with DNA translocation are recorded when an ionic strength gradient is imposed across the nanopores. Measurements and modelling show that field-effect transistor signals are generated by highly localized changes in the electrical potential during DNA translocation, and that nanowire-nanopore sensors could enable large-scale integration with a high intrinsic bandwidth.