Identification of single nucleotides in MoS2 nanopores

TL;DR

This paper introduces a viscosity gradient system using ionic liquids to control DNA translocation speed through MoS2 nanopores, enabling accurate single-nucleotide identification for improved DNA sequencing.

Contribution

The study demonstrates for the first time the statistical identification of all four nucleotides using MoS2 nanopores with controlled translocation speeds.

Findings

Achieved nucleotide identification with SNR > 10

Controlled DNA translocation speed to 1-50 nt/ms

Enabled all four nucleotides to be distinguished in solid-state nanopores

Abstract

Ultrathin membranes have drawn much attention due to their unprecedented spatial resolution for DNA nanopore sequencing. However, the high translocation velocity (3000-50000 nt/ms) of DNA molecules moving across such membranes limits their usability. To this end, we have introduced a viscosity gradient system based on room-temperature ionic liquids (RTILs) to control the dynamics of DNA translocation through a nanometer-size pore fabricated in an atomically thin MoS2 membrane. This allows us for the first time to statistically identify all four types of nucleotides with solid state nanopores. Nucleotides are identified according to the current signatures recorded during their transient residence in the narrow orifice of the atomically thin MoS2 nanopore. In this novel architecture that exploits high viscosity of RTIL, we demonstrate single-nucleotide translocation velocity that is an optimal speed (1-50 nt/ms) for DNA sequencing, while keeping the signal to noise ratio (SNR) higher than 10. Our findings pave the way for future low-cost and rapid DNA sequencing using solid-state nanopores.