DNA Base Detection Using a Single-Layer MoS₂

Nanopore-based DNA sequencing has led to fast and high-resolution recognition and detection of DNA bases. Solid-state and biological nanopores have low signal-to-noise ratio (SNR) (< 10) and are generally too thick (> 5 nm) to be able to read at single-base resolution. 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>i.e.</i>, nanopore and nanochannel). A MoS₂ nanopore shows four distinct 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 (<i>e.g.</i>, 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 <i>via</i> 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