DFT Study of N-hydroxyurea Adsorption Behavior onto Pristine and Iron-doped Single-walled Carbon Nanotube

The interactions between N-hydroxyurea (NHU) as anticancer drug and SWCNTs (pure and Fe-doped) were investigated with density functional theory. In this study, large long-range corrected CAM-B3LYP and B3LYP were employed to investigate the stability of the different NHU-CNT and NHU/Fe-CNT complexes in the gas phase and solution (water). The presence of an iron atom would create the suitable space on the nanotube surface for the adsorption between drug and nanotubes. The results revealed that the adsorption of drugs on the outer surface of both nanotubes was energetically favorable and the reactivity of Fe-doped complexes increased compared to pristine nanotubes. Results indicated that adsorption is dependent on the sites of the drug. NBO, QTAIM and NCI-RDG analyses were applied for further understanding of the adsorption process. The data suggested that the doping of iron atom increases the adsorption ability.