Single nucleobase identification for transversally-confined ssDNA using longitudinal ionic currents

High-fidelity DNA sequencing using solid-state nanopores remains a big challenge, partly due to difficulties related to efficient molecular capture and subsequent control of the dwell time. To help address these issues, here we propose a sequencing platform consisting of stacked two-dimensional materials with tailored structures containing a funnel-shaped step defect and a nanopore drilled inside the nanochannel. Our all-atom molecular dynamics (MD) simulations showed that, assisted by the step defect, single-stranded DNA (ssDNA) can be transported to the nanopore in a deterministic way by pulsed transversal electric fields. Furthermore, different types of DNA bases can reside in the pore for a sufficiently long time which can be successfully differentiated by longitudinal ionic currents. By using the decoupled driving forces for ssDNA transport and ionic current measurements, this approach holds potential for high-fidelity DNA sequencing.