In-plane graphene/h-BN/graphene heterostructures with nanopores for electrical detection of DNA nucleotides.

Abstract

The in-plane heterostructure of graphene and h-BN has unique physical and electrical characteristics, which can be exploited for single-molecule DNA sequencing. On this account, we propose a nanostructure based on a nanopore in graphene/h-BN/graphene heterostructures as a viable approach for in-plane electrical detection. The insulating h-BN layer changes the charge transport to the quantum tunneling regime, which is very sensitive to the electrostatic interactions induced by nucleotides during their translocation through the nanopore. Density functional theory (DFT) is utilized to study the membrane/nanopore interactions as well as their interactions with different nucleotides (dAMP, dGMP, dCMP, and dTMP). The results indicate that the nucleotides show stronger interactions with nanopores in h-BN rather than nanopores in pristine graphene. For the calculation of electronic transport, non-equilibrium Green's function (NEGF) formalism at the first principles level is employed. The in-plane currents at different applied voltages are calculated in the presence of different nucleotides in the nanopore. The sensitivity of the proposed nanostructure towards different nucleotides is measured based on the current modulation induced by each nucleotide. The graphene/h-BN/graphene heterostructure shows higher sensitivity toward different nucleotides compared to a similar structure consisting of pristine graphene and can be considered as a promising candidate for DNA sequencing applications.