A DFT study of penicillamine adsorption over pure and Al-doped C60 fullerene

This study considers the effects of penicillamine adsorption over structural and electronic properties of pure and Al-doped C60 fullerene in the gas phase using density functional theory (DFT) calculations. Our calculations demonstrate that penicillamine is weakly adsorbed on pure C60 fullerene with a binding energy (Eb) of − 0.12 eV by B3LYP and − 0.13 eV by B3PW91 functional. Both electronic and structural properties were explored in terms of dipole moment, binding energies, and frontier molecular orbitals. In contrast to pristine C60, the binding energy of the Al-C60–NH2 complex is much stronger and HOMO–LUMO energy gaps are slightly reduced. The values of global hardness, HOMO–LUMO energy gap, and ionization potential of Al-doped C60–drug (NH2 group) are decreased and cause lowering of stability and increase in reactivity of the complex. Our results suggest that doping may improve drug delivery capacity of C60 fullerene.