Quantum mechanical investigation into the electronic transport properties of a memantine-functionalized gold nanopore biosensor for natural and mutated DNA nucleobase detection

Abstract

Quantum mechanical studies of the electronic transport properties of a memantine-functionalized gold nanopore biosensor for natural and mutated DNA nucleobase detection are reported. In this study, a gold electrode was functionalized with a modified diamondoid structure, called memantine, and the tunnelling current arising from nucleobases was investigated as it translated through the functionalized gold nanopore. Non-equilibrium Green's function (NEGF) and density functional theorem (DFT) methods have been used to analyze and calculate the results. The transmission spectrum for each nucleobase is presented. In order to justify that the resonance peaks are originating from the nucleobases, the Projected Densities of States (PDOS) of the nucleobases were plotted and compared with their corresponding transmission spectra. The electronic wave functions relating to transmission and the device sensitivity have also been shown. The proposed device is demonstrated to detect various natural and mutated nucleobases with a sensitivity ranging from 10³ to 10⁷. Finally, differential conductance methods have been found to be effective in detecting nucleobases in the case of overlapping transmission peaks.