Theoretical studies on key factors in DNA sequencing using atomically thin molybdenum disulfide nanopores

Abstract

Nanopore-based DNA sequencing is considered to be a low-cost, high resolution and superfast method. Solid state nanopores, especially MoS₂ nanopores, have been considered to be a promising choice for DNA sequencing. However, researchers still have a very limited understanding of the effects of multiple factors on MoS₂-based DNA sequencing. In this study, the effects of the applied voltage and the diameter of the MoS₂ nanopore on the resolution of DNA sequencing were investigated. Our results demonstrate that the translocation time of DNA can increase with a decrease in the applied voltage. DNA can be stretched significantly to translocate a 2 nm nanopore under a high applied voltage (>400 mV nm⁻¹). To achieve a 1 base per μs translocation speed (1 GHz bandwidth), we suggest that three methods could be applied, including a decrease in the applied voltage, a decrease in the diameter of the MoS₂ nanopore or modification of the MoS₂ nanopore. In addition, the size of the nanopore can severely affect the possibility of DNA entering the nanopore, and the translocation time of DNA could be significantly increased with a smaller MoS₂ nanopore. These findings may help to design MoS₂ nanopores with higher resolution for use in DNA sequencing.