Interaction of DNA nucleobases with boron, nitrogen, and sulfur doped graphene nano-ribbon for sequencing: An Ab initio study

摘要

In this paper, we report on the conductance behavior of the boron and nitrogen doped 8 armchair graphene nanoribbons (8-AGNR) with the four DNA canonical nucleobases by means of density functional theory (DFT) combined with non-equilibrium Green's function (NEGF). For any given dopant, all eight possible substitutional sites in the 8-AGNR are examined in an attempt to investigate the effect of the dopant atom in a specific site on the sensitivity of the doped AGNR. Our results indicate that generally Baffects the negative energy portion of the transmission spectrum, while N impacts its positive energy portion. Furthermore, unlike the case for nitrogen dopant, nano-ribbon's conductance is distinctively modulated when B takes certain substitutional sites. We confirm this picture by presenting a comprehensive study on charge transfer between nucleobases and GNR as well as doped GNR confirm that adding dopant slightly changes optimum distance and charge distribution of the system. We find that while incorporation of dopant atom in GNR changes the orbitals at energies near what a nucleobase would do, the result for doped GNR interacting with specified nucleobase is enhanced. We also compare our results to that of other devices on 2D nanoribbons.