First-Principles Density Functional Theory Study on Graphene and Borophene Nanopores for Individual Identification of DNA Nucleotides

The advancement in DNA sequencing has massively improved the biological and medicinal research, leading to the development of new medical diagnosis and forensic applications. It puts forward a pool of information that could be harnessed to realize personalized medicine toward various deadly diseases. Recent developments in solid-state nanopore-based sequencing technology have drawn much attention owing to its potential to achieve fast, cost-effective, reliable, and single-shot nucleotide identification. Here, we have proposed atomically thin graphene and χ3 borophene nanopore-based devices for DNA sequencing. The structural and electronic properties of the graphene pore and χ3 borophene pore with and without DNA nucleotides have been studied by employing first-principles density functional theory (DFT) calculations. Using the DFT and non-equilibrium Green’s function formalism (NEGF), we have studied the transverse conductance and current–voltage (I–V) characteristics of all the systems. We have observed that nucleotides are weakly interacting with the χ3 borophene pore compared with the graphene pore, indicating higher translocation speed and shorter residence time inside the χ3 borophene pore. In case of both the nanopores, the operating current across the devices is within the range of microampere (μA), which is several orders higher magnitude than that of the previously reported nanogap/nanopore-based devices. The I–V results show that the graphene nanopore-based device is promising for individual identification of nucleotides compared to the χ3 borophene pore-based device, and the results are promising compared to even the graphene nanogap-based systems reported earlier.