Ab-Initio study of dopamine, absorbic acid and uric acid adsorption on graphene and InBi monolayer with effects of charging and green’s function method
Abstract
Dopamine (DA) is a crucial molecule for the central nervous system, and the ability to detect it in samples containing molecules such as Ascorbic Acid (AA) and Uric Acid (UA) could facilitate early diagnosis of related disorders. In this work, the interaction of DA, UA, and AA with InBi and Graphene (GR) monolayers under charging was investigated using Density Functional Theory (DFT) calculations with van der Waals (vdW) correction and nonequilibrium Green’s function method for the first time. According to our calculations, the most influential factor in the interaction was observed to arise from the π–π and π–O interaction between molecules and surfaces. It has been concluded that InBi is a better adsorbent than GR for DA, AA, and UA, where the adsorption energies from the highest to lowest were found as UA>AA>DA. Furthermore, the charge transfers between molecules and surfaces were investigated, and it was demonstrated that the molecules on GR act as charge acceptors. In contrast, for InBi–molecule systems, electronic drift from molecules to the InBi surface was observed. The Partial Density of States (P-DOS) plots were examined, and the results were discussed in detail. The consequences of adding/removing charges to/from the systems were also examined, and it was shown that removing Q=2e/cell from the GR–molecule systems effectively detected DA molecules from the others. Charging also broke the topological state of InBi, leading to semiconductor to metal, except for the Q=−2e/cell case. Finally, the changes in transmittance due to adsorption were simulated, and our results show that InBi is a possible candidate for DA sequencing biosensor applications compared to GR. The findings of this work provide a theoretical framework for the development and creation of highly precise biodevices and biosensors.
