Density functional investigations on the adsorption characteristics of nucleobases on germanene nanoribbons

In order to explore the possibility of using 2D nanostructures as biosensors, we have studied the adsorption characteristics of nucleotide bases on armchair germanene nanoribbon (AGeNR) using density functional theory with several approximations of exchange-correlation functionals with the addition of dispersion correction. It has been found that the dispersion interactions have the key role in characterizing adsorption phenomena through the non-covalent interactions. The structural and electronic properties of the nucleobase-nanoribbon complexes have been investigated along with the study of the dependence of binding energies on ribbon widths and hence the edge (armchair or zigzag) effects. A physisorption process with binding energies in the range of about 0.83-1.37 eV has been found for 10-AGeNR, which alters the electronic and structural properties of the subsystems indicating the potential use of these complexes as biosensors.