A potential sensing mechanism for DNA nucleobases by optical properties of GO and MoS2 Nanopores

Abstract

We propose a new DNA sensing mechanism based on optical properties of graphene oxide (GO) and molybdenum disulphide (MoS2) nanopores. In this method, GO and MoS2 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 MoS2 we use them as nanopore materials. The absorption and emission peaks wavelengths of GO and MoS2 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 MoS2 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.