A potential sensing mechanism for DNA nucleobases by optical properties of GO and MoS ₂ Nanopores

Abstract

We propose a new DNA sensing mechanism based on optical properties of graphene oxide (GO) and molybdenum disulphide ( MoS ₂) nanopores. In this method, GO and MoS ₂ is utilized as quantum dot (QD) nanopore and DNA molecule translocate through the nanopore. A recently-developed hybrid quantum/classical method (HQCM) is employed which uses time-dependent density functional theory and quasi-static finite difference time domain approach. Due to good biocompatibility, stability and excitation wavelength dependent emission behavior of GO and MoS ₂ we use them as nanopore materials. The absorption and emission peaks wavelengths of GO and MoS ₂ nanopores are investigated in the presence of DNA nucleobases. The maximum sensitivity of the proposed method to DNA is achieved for the 2-nm GO nanopore. Results show that insertion of DNA nucleobases in the nanopore shifts the wavelength of the emitted light from GO or MoS ₂ nanopore up to 130 nm. The maximum value of the relative shift between two different nucleobases is achieved by the shift between cytosine (C) and thymine (T) nucleobases, ~111 nm for 2-nm GO nanopore. Results show that the proposed mechanism has a superior capability to be used in future DNA sequencers.