Potential application of Al and Si doped carbon nanotubes for metronidazole detection: A theoretical study

The interaction of metronidazole (MNZ) drug with pristine, Al and Si doped single-walled carbon nanotubes (SWCNTs) was explored utilizing density functional theory (DFT) method. The calculations revealed that MNZ prefers to be adsorbed on the pristine CNT via its 5-membered ring with an Eadsorption value of −17.88 kcal.mol−1. The HOMO-LUMO energy gap (Eg) of pristine CNT increases by about 60.9% upon adsorption of MNZ. MNZ molecule prefers to be adsorbed on the Al- and Si doped CNT via its NO2 group with a binding energy of about −43.94 and −49.25 kcal mol−1, respectively. The electronic properties of SiCNT are more sensitive to MNZ adsorption than those of AlCNT but not pristine CNT. The recovery time of MNZ from the CNT, AlCNT and SiCNT nanostructures is calculated to be about 1.24 × 10−3, 1.51 × 1016, and 1.17 × 1020 s, respectively, indicating AlCNT and SiCNT suffer from a very long recovery time compared to pristine nanotube.