High sensitivity of deoxyribonucleic acid detection via graphene nanohole/si micro-nanopore structure fabricated by focused ion beam

Abstract

Detection via nanohole is a simple sensing tool to analyze various biopolymers with high sensitivity. This paper reports the detection of deoxyribonucleic acid (DNA) biomolecules using an integration of 30 nm circular-shaped graphene nanohole and conical-shaped silicon (Si) micro-nanopore fabricated by focused ion beam technique. The ionic current changes at different DNA volume measured via a single and an array of nanoholes seem to confirm the ionic current blockade phenomena where the current decreases in stable linearity with the increase of volume. Regardless of the number of nanoholes, the sensitivity of around 110 nA/µL for both devices shows relatively much higher value as compared to the sensitivity reported in the other literatures. Such significant ionic current blockade detection suggests that a proposed combination of conical-shaped Si micro-nanopore and graphene nanohole are able to act as a promising fluidic channel and sensing membrane, respectively, towards a realization of high sensitive DNA biosensors.