Single-Layer Molebdenum Disulphide Nanopore for DNA Detection

Abstract

Nanopore-based DNA sequencing has paved the way toward fast, label-free and high-resolution recognition and detection of DNA bases. Solid-state and biological nanopores have low signal-to-noise ratio (SNR) ( 5 nm) to be able to distinguish between bases distinctly. A nanopore in graphene, a 2-D material with sub-nanometer thickness, has a SNR of ∼3 under DNA ionic current. In this report, using atomistic and quantum simulations, we find that a single-layer MoS2 is an extraordinary material (with a SNR > 15) for DNA sequencing by two competing technologies (i.e., nanopore and nanochannel). DNA sticks to the surface of graphene nanopore which is the origin of noise generation. MoS2 surface shows non-sticky behavior and bases translocate through the pore without sticking. MoS2 nanopore also shows four distinguishable ionic current signals for single-nucleobase detection with low noise. In addition, a single-layer MoS2 shows a characteristic change/response in the total density of states for each base. The band gap of MoS2 is significantly changed compared to other nanomaterials (e.g., graphene, h-BN, and silicon nanowire) when bases are placed on top of the pristine MoS2 and armchair MoS2 nanoribbon, thus making MoS2 a promising material for base detection via transverse current tunneling measurement. MoS2 nanopore benefits from a craftable pore architecture (combination of Mo and S atoms at the edge) which can be engineered to obtain the optimum sequencing signals.