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 throughput1–4. Although single-base resolution and differentiation have been demonstrated with nanopores using ionic current measurements5–7, direct sequencing has not been achieved due to difficulties in recording very small (~pA) ionic current at a bandwidth consistent with fast translocation speeds1–3. Here we show that solid-state nanopores can be combined with silicon nanowire field-effect transistors (FETs) to create sensors in which detection is localised and self-aligned at the nanopore. Well-defined FET signals associated with DNA translocation are recorded when an ionic strength gradient is imposed across the nanopores. Measurements and modelling show that FET signals are generated by highly-localized changes in the electrical potential during DNA translocation and that the nanowire-nanopore sensors could enable large-scale integration with a high intrinsic bandwidth. Current nanopore technology is based on detecting a modulation in the ionic current due to the partial blockade of a nanopore during DNA translocation1–4. Significant progress has been made towards realizing the goal of direct DNA sequencing during translocatio