Vacancy on the surface of monolayer MoS2 to improve the sensitivity for DNA/RNA sequencing: A DFT study

Abstract

The layered two-dimensional nanomaterial MoS2 is a promising material for DNA/RNA sequence owing to its unique physical and chemical properties. However, pristine MoS2 nanosheets show poor sensitivity in distinguishing nucleobases molecules. In this study, density functional theory (DFT) calculations were employed to study the vacancies on MoS2 surfaces to enhance the sensitivity and distinctions toward five nucleobase molecules. Monolayer MoS2 with Mo vacancy (VMo-MoS2) and S vacancy (VS-MoS2) were created. The results show that the sensitivity (S%) of pristine MoS2 was low because the change in the band gap was very small when interacting with T and U. VMo-MoS2 has a greater advantage in distinguishing nucleobase molecules because of the larger standard deviations(θ). The VMo-MoS2 could effectively improve the sensitivity to distinguish T and U because S% was improved from 0.15 % to 3.1 % for U and 1.06 % to 6.9 % for T when they interact with VMo-MoS2 than the pristine MoS2. Because of the physical interactions, the recovery time was short and no more than 4.27 s at 333 K for VMo-MoS2. Therefore, VMo-MoS2 is a promising candidate for DNA sequencing.