Adsorption behavior of metformin drug on boron nitride fullerenes: Thermodynamics and DFT studies

In this study, a density functional theory (DFT) calculation was carried out for the adsorption behavior and detection of metformin on the exterior surfaces of pure and doped boron nitride (BN) fullerenes by using B3LYP-D and PW91-D functionals. The results demonstrate that the -NH group of metformin can chemisorb on the boron atom of B12N12 and B16N16 fullerenes. Presence of polar solvent (water) increases the adsorption energy of metformin on the pure and GaB11N12 fullerenes. However, at the presence of Ga doping and it was found that the doping increases the binding energy of the metformin molecule, while the Ge doping decreases the binding energy. So our calculations suggest that the GeB11N12 has a greater sensitivity for the metformin molecule compared with the GaB11N12 fullerene. Our results represented that the GeB11N12 fullerene has good potential as a biosensor for the determination of metformin in environmental systems. (C) 2018 Published by Elsevier B.V.