Electronic Conductance and Current Modulation through Graphdiyne Nanopores for DNA Sequencing

Abstract

Solid-state nanopore devices have emerged as one of the most promising technologies that may decode the sequence of DNA nucleobases by reading electronic conductance and electric current signals. Herein we study the potential of atomically thick graphdiyne (GDY) to act as an all-electronic nanopore (NP)-based DNA sequencing device. The first-principles density functional theory method is used to study the structural properties, interaction energy (Ei) values, translocation time (τ), charge transfer [Q(e)] values, charge density difference [Δρ(r)], molecular orbital (MO) positions, and electronic density of states (DOS) properties of the GDYNP and GDYNP + nucleobase (nucleobases: adenine (A), guanine (G), thymine (T), and cytosine (C)) systems. Our results suggest that the GDYNP system could be a suitable device for the detection of nucleobases due to their specific translocation times inside the GDYNP device. The Δρ(r) results reveal that the charge fluctuates around the GDYNP edges close to the target nucleobase. This charge reorganization causes the modulation of charge transport in the GDYNP device. Furthermore, the GDYNP device is used to read-out the conductance and current signals of each DNA nucleobase while located inside the GDYNP by using nonequilibrium Green’s functions formalism. Our findings show a change in conductance with respect to the reference bare “GDYNP” device for energy values below/above the Fermi energy. The conductance as well as current sensitivity (%) values (C > G > T > A) indicates that the nucleobases could possibly be sequenced through the GDYNP device. Further, each nucleobase transmits unique current signals when transported through the GDYNP device. A distinction between purine- and pyrimidine-type nucleobases seems possible due to their different current signals. Thus, our study highlights the potentials that would motivate research toward the development of the GDYNP device, which may be even a better DNA nucleobase detector compared to graphene-based devices. © 2021 American Chemical Society