Aviram-Ratner rectifying mechanism for DNA base pair sequencing through graphene nanogaps

TL;DR

This paper demonstrates that DNA base pairs can act as rectifiers in graphene nanogaps, with potential for rapid DNA sequencing by exploiting their asymmetric electrical responses.

Contribution

It introduces the concept of biological DNA base pairs functioning as rectifiers and computationally analyzes their electrical response in graphene nanogaps for sequencing.

Findings

Cytosine-Guanine pair shows asymmetric I-V response

Thymine-Adenine pair exhibits symmetric I-V response

Proposes using rectification asymmetry for DNA sequencing

Abstract

We demonstrate that biological molecules such as Watson-Crick DNA base pairs can behave as biological Aviram-Ratner electrical rectifiers because of the spatial separation and weak hydrogen bonding between the nucleobases. We have performed a parallel computational implementation of the ab-initio non-equilibrium Green's function (NEGF) theory to determine the electrical response of graphene---base-pair---graphene junctions. The results show an asymmetric (rectifying) current-voltage response for the Cytosine-Guanine base pair adsorbed on a graphene nanogap. In sharp contrast we find a symmetric response for the Thymine-Adenine case. We propose applying the asymmetry of the current-voltage response as a sensing criterion to the technological challenge of rapid DNA sequencing via graphene nanogaps.