DNA-Graphene Interactions During Translocation Through Nanogaps

TL;DR

This study investigates how double-stranded DNA translocates through novel graphene nanogaps, revealing unique signatures and interactions that are crucial for developing graphene-based single-molecule sensing and sequencing technologies.

Contribution

The paper introduces a new fabrication method for graphene nanogaps and characterizes DNA translocation behavior, highlighting the importance of DNA-graphene interactions in device performance.

Findings

Translocation signatures differ from circular nanopores.

Translocation time and conductance vary by approximately 100%.

Exponential relaxation of current traces suggests slow membrane relaxation.

Abstract

We study how double-stranded DNA translocates through graphene nanogaps. Nanogaps are fabricated with a novel capillary-force induced graphene nanogap formation technique. DNA translocation signatures for nanogaps are qualitatively different from those obtained with circular nanopores, owing to the distinct shape of the gaps discussed here. Translocation time and conductance values vary by $\sim 100$%, which we suggest are caused by local gap width variations. We also observe exponentially relaxing current traces. We suggest that slow relaxation of the graphene membrane following DNA translocation may be responsible. We conclude that DNA-graphene interactions are important, and need to be considered for graphene-nanogap based devices. This work further opens up new avenues for direct read of single molecule activitities, and possibly sequencing.