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

The Density Functional Theory (DFT) and the Natural Bond Orbital (NBO) calculations based method 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 of compounds, Muliken charges, occupancy, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), the HOMO-LUMO band gap and the electronic chemical potential (μ) were calculated. The NBO analysis showed there is a hyperconjugative interaction between Oxygen and Nitrogen lone — pair electrons of dopamine and a' or I orbitals of carbon atom of nanotube. Results indicated that the composite between nanotubes and the Ncentered dopamine is more stable than 01 - centered dopamine and both of them are stable than the single agent.