Sensitive DNA detection based on the capacitance properties of graphene

Abstract

In the present paper, a new method is proposed to distinguish the DNA nucleotides based on a first-principles calculation of the electronic features of DNA bases which are chemisorbed to a graphene sheet placed between two gold electrodes in a contact-channel-contact system. The capacitance properties of graphene in the channel are simulated and analyzed using non-equilibrium Green's functions combined with density functional theory. Thus, the capacitance properties of graphene are theoretically deciphered in a biological environment, and, using a novel method, the effect of the chemisorbed DNA nucleotides on electrical charges on the surface of graphene is investigated. Several parameters in this method are also extracted including the electrostatic energy, induced density, induced electrostatic potential, electron difference potential, and electron difference density. The qualitative and quantitative differences among these parameters can be used to identify DNA nucleotides.

Graphene‐hBN Hybrid Nanogap for Boosting DNA Nucleobases Recognition Sensitivity

“…Thanks to graphene's single‐atomic thickness, of the order of the distance between two consecutive bases in DNA, it is possible to detect nucleobases by transverse conductance measurements . Experimental progress in the realization of graphene based nanogaps or nanoelectrodes with fine spatial resolution,, and several reports in the literature suggest graphene nanogap electrodes as a good platform for DNA sensing ,,. In this regard, the concept of electron tunneling can be used as a readout mechanism to record information for characterizing the molecules …”