Coupled nanopores for single-molecule detection

Abstract

Rapid sensing of molecules is increasingly important in many studies and applications, such as DNA sequencing and protein identification. Here, beyond atomically thin 2D nanopores, we conceptualize, simulate and experimentally demonstrate coupled, guiding and reusable bilayer nanopore platforms, enabling advanced ultrafast detection of unmodified molecules. The bottom layer can collimate and decelerate the molecule before it enters the sensing zone, and the top 2D pore (~2 nm) enables position sensing. We varied the number of pores in the bottom layer from one to nine while fixing one 2D pore in the top layer. When the number of pores in the bottom layer is reduced to one, sensing is performed by both layers, and distinct T- and W-shaped translocation signals indicate the precise position of molecules and are sensitive to fragment lengths. This is uniquely enabled by microsecond resolution capabilities and precision nanofabrication. Coupled nanopores represent configurable multifunctional systems with inter- and intralayer structures for improved electromechanical control and prolonged dwell times in a 2D sensing zone. In this study, the authors present the design and fabrication of reusable, atomically thin, coupled bilayer solid-state nanopores that enable the slowing down and positional tracking of molecules for label-free, single-molecule sensing.