Effect of Structural Defects on the Interaction of DNA Bases with Graphene Nanoribbons: van der Waals Corrected Density Functional Theory Calculations

Graphene is a promising material for a wide range of applications including the sensing and sequencing of DNA nucleobases. In this study, we investigated the adsorption of four DNA nucleobases (adenine, guanine, thymine, and cytosine) on atomically thin armchair graphene nanoribbons (AGNRs) using density functional theory (DFT). The binding energies of the nucleobases on AGNRs were examined for AGNRs containing no surface defects, containing Stone-Wales (SW) defects, and containing di-vacancy (DV) defects. The geometry optimizations of the four DNA bases on AGNRs were performed using van der Waals corrected (vdW-DF2 and semi-empirical Grimme’s-D2) DFT calculations. The DNA nucleobases showed different binding strengths on graphene, and their binding energies followed the order: G > A > T > C.  The presence of structural defects on the AGNRs showed no significant change on the computed binding energies and band gaps of the DNA bases.