DNA Translocation through Graphene Nanopores

TLDR

Graphene, unlike insulating solid‑state nanopore materials, is an excellent electrical conductor. The study investigates DNA translocation through nanopores fabricated in graphene membranes. The devices are 1–5 nm thick graphene membranes with electron‑beam sculpted 5–10 nm pores. The thin graphene pores produce larger blocked currents but several orders of magnitude higher ionic‑current noise than silicon nitride, which is mitigated by a 5 nm TiO₂ coating, suggesting graphene enables direct electronic sensing at the pore.

Abstract

We report on DNA translocations through nanopores created in graphene membranes. Devices consist of 1−5 nm thick graphene membranes with electron-beam sculpted nanopores from 5 to 10 nm in diameter. Due to the thin nature of the graphene membranes, we observe larger blocked currents than for traditional solid-state nanopores. However, ionic current noise levels are several orders of magnitude larger than those for silicon nitride nanopores. These fluctuations are reduced with the atomic-layer deposition of 5 nm of titanium dioxide over the device. Unlike traditional solid-state nanopore materials that are insulating, graphene is an excellent electrical conductor. Use of graphene as a membrane material opens the door to a new class of nanopore devices in which electronic sensing and control are performed directly at the pore.