Transverse Electronic Transport through DNA Nucleotides with Functionalized Graphene Electrodes

TL;DR

This study uses first-principles calculations to explore how functionalized graphene electrodes can distinguish DNA nucleotides through transverse electronic conductance, revealing unique tunneling behaviors including negative differential resistance.

Contribution

It demonstrates the potential of functionalized graphene nanogaps for DNA sequencing by analyzing nucleotide-specific conductance properties with advanced computational methods.

Findings

Distinct conductance signatures for each nucleotide

Identification of a negative differential resistance effect

Optimal bias voltage for nucleotide differentiation

Abstract

Graphene nanogaps and nanopores show potential for the purpose of electrical DNA sequencing, in particular because single-base resolution appears to be readily achievable. Here, we evaluated from first principles the advantages of a nanogap setup with functionalized graphene edges. To this end, we employed density functional theory and the non-equilibrium Green's function method to investigate the transverse conductance properties of the four nucleotides occurring in DNA when located between the opposing functionalized graphene electrodes. In particular, we determined the electrical tunneling current variation as a function of the applied bias and the associated differential conductance at a voltage which appears suitable to distinguish between the four nucleotides. Intriguingly, we observe for one of the nucleotides a negative differential resistance effect.