Enhanced DNA sequencing performance through edge-hydrogenation of graphene electrodes

TL;DR

This study demonstrates that edge-hydrogenation of graphene electrodes significantly enhances DNA sequencing by increasing conductivity and reducing translocation speed, thereby improving measurement accuracy in nanopore-based sequencing.

Contribution

The paper introduces the novel concept of hydrogenating graphene electrode edges to improve solid-state nanopore DNA sequencing performance.

Findings

Edge-hydrogenation increases conductivity by about 1000 times.

Hydrogenation reduces statistical variance in measurements.

Different effects observed depending on electrode separation distance.

Abstract

We propose using graphene electrodes with hydrogenated edges for solid-state nanopore-based DNA sequencing, and perform molecular dynamics simulations in conjunction with electronic transport calculations to explore the potential merits of this idea. The results of our investigation show that, compared to the unhydrogenated system, edge-hydrogenated graphene electrodes facilitate the temporary formation of H-bonds with suitable atomic sites in the translocating DNA molecule. As a consequence, the average conductivity is drastically raised by about 3 orders of magnitude while exhibiting significantly reduced statistical variance. We have furthermore investigated how these results are affected when the distance between opposing electrodes is varied and have identified two regimes: for narrow electrode separation, the mere hindrance due to the presence of protruding hydrogen atoms in the nanopore is deemed more important, while for wider electrode separation, the formation of H-bonds becomes the dominant effect. Based on these findings, we conclude that hydrogenation of graphene electrode edges represents a promising approach to reduce the translocation speed of DNA through the nanopore and substantially improve the accuracy of the measurement process for whole-genome sequencing.