Topological Line Defects around Graphene Nanopores for DNA Sequencing

TL;DR

This paper proposes using topological line defects in graphene nanopores to enhance DNA nucleobase discrimination in sequencing devices by modulating conductance with solvent effects and molecular dynamics simulations.

Contribution

It introduces a novel approach of employing extended line defects in graphene to improve nucleobase selectivity in nanopore-based DNA sequencing.

Findings

Distinguishing nucleobases via conductance modulation is theoretically feasible.

Gate voltage tuning enhances nucleobase discrimination.

Solvent effects are fully accounted for in conductance analysis.

Abstract

Topological line defects in graphene represent an ideal way to produce highly controlled structures with reduced dimensionality that can be used in electronic devices. In this work we propose using extended line defects in graphene to improve nucleobase selectivity in nanopore-based DNA sequencing devices. We use a combination of QM/MM and non-equilibrium Green's functions methods to investigate the conductance modulation, fully accounting for solvent effects. By sampling over a large number of different orientations generated from molecular dynamics simulations, we theoretically demonstrate that distinguishing between the four nucleobases using line defects in a graphene-based electronic device appears possible. The changes in conductance are associated with transport across specific molecular states near the Fermi level and their coupling to the pore. Through the application of a specifically tuned gate voltage, such a device would be able to discriminate the four types of nucleobases more reliably than that of graphene sensors without topological line defects.