Transverse conductance of DNA nucleotides in a graphene nanogap from first principles

TL;DR

This paper uses first-principles calculations to evaluate the potential of graphene nanogaps for DNA sequencing by analyzing the electrical conductance differences among nucleotides.

Contribution

It provides a theoretical assessment of the transverse conductance of DNA nucleotides in graphene nanogaps, demonstrating the feasibility of distinguishing bases for sequencing.

Findings

Distinct conductance signals for different nucleotides.

Current fluctuations over several orders of magnitude.

Potential for rapid whole-genome sequencing.

Abstract

The fabrication of nanopores in atomically-thin graphene has recently been achieved and translocation of DNA has been demonstrated. Taken together with an earlier proposal to use graphene nanogaps for the purpose of DNA sequencing, this approach can resolve the technical problem of achieving single-base resolution in electronic nucleobase detection. We have theoretically evaluated the performance of a graphene nanogap setup for the purpose of whole-genome sequencing, by employing density functional theory and the non-equilibrium Green's function method to investigate the transverse conductance properties of nucleotides inside the gap. In particular, we determined the electrical tunneling current variation at finite bias due to changes in the nucleotides orientation and lateral position. Although the resulting tunneling current is found to fluctuate over several orders of magnitudes, a distinction between the four DNA bases appears possible, thus ranking the approach promising for rapid whole-genome sequencing applications.