Nanopore Chip with Self-Aligned Transverse Tunneling Junction for Biomolecule Detection and Sequencing

There is an urgent need for a technique to directly sequence DNA/RNA with chemical specificity and accuracy for detection at single-molecule level. Solid-state nanopore technology has the potential of having tunneling electrodes as a new readout mechanism for higher resolution detection. However, fabrication of such structures has been extremely challenging. Here we report a new strategy for fabricating a solid-state nanopore with transverse tunneling junction integrated inside a nanofluidic channel, where DNA molecules can be enriched and straightened to pass through the nanopore between the electrodes. The nanopore size is then reversibly tuned through a controlled electrochemical process in real time. We have successfully shown that coincidental ionic and tunneling signals can be reproducibly detected for DNA translocation events with >93% yield. We have also observed events related to DNA bridging the transverse electrodes, which showed different amplitude and duration distribution compared to translocating events. With additional optimization of multiplexed detection and translocation control, our design can be further developed into a low-cost platform for single biomolecule delivery, manipulation, detection and sequencing.