The Interaction between Dopamine and Carbon Nanotube: A DFT and NBO Approach

The Density Functional Theory (DFT) and the Natural Bond Orbital (NBO) calculations basedmethod B3LYP/6-31G were carried out to study the interaction of Dopamine with carbon nanotube.The nanotube used in this study, includes 60 C atoms (6, 6) type. Relative and formation energies ofcompounds, Muliken charges, occupancy, the highest occupied molecular orbital (HOMO) and thelowest unoccupied molecular orbital (LUMO), the HOMO-LUMO band gap and the electronicchemical potential (μ) were calculated. The NBO analysis showed there is a hyperconjugativeinteraction between Oxygen and Nitrogen lone — pair electrons of dopamine and a' or I orbitals ofcarbon atom of nanotube. Results indicated that the composite between nanotubes and the Ncentereddopamine is more stable than 01 - centered dopamine and both of them are stable than thesingle agent.