Enhanced interaction and biosensing properties of dopamine molecule over the surface of Ag-decorated arsenene nanosheets: A DFT study

The investigation of adsorption properties of dopamine has aroused significant attention in search for the design of effective biosensors. In this work, arsenene-based biosensors functionalized with Ag atoms are modeled and optimized using DFT calculations. The adsorption and surface reactivity of dopamine molecule can be enhanced over the Ag-functionalized arsenene nanostructures compared with the pristine systems. Charge density difference plots and total charge distribution analysis indicate the significant accumulation of charge densities over the adsorbed Ag atom and dopamine molecule. Compared with pure arsenene, surface modification by Ag adatom enhances the reactivity of arsenene, which is very conducive to biosensing of dopamine by arsenene surface. Moreover, in the PDOS analysis, there are great peak overlaps between Ag–O and Ag–N atoms, confirming the formation of chemical bonds between the Ag and O or N atoms. Our results indicate the substantial efficiency of Ag-functionalized arsenene nanosheets for sensing dopamine molecules.