In the current study, the possibility of the complex formation between some alkaloids and monohydroxy-cucurbit[8/10] urils was investigated via molecular dynamic (MD) simulation and density functional theory (DFT) calculations. On the basis of the MD simulations, the stability of all complexes increases in the presence of graphene oxide (HO-CB[n]/GO). Also, the selectivity of HO-CB[n] and HO-CB[n]/GO toward alkaloids was analyzed. The obtained results showed that the complex of thebaine and HO-CB[10]/GO is the most stable structure in water. DFT (M06-2X) and DFT-D3 (M06-2X-D3) functionals were applied for geometry optimization of the complexes. To have a comprehensive understanding of the mechanism of drug sensing by the proposed composites, Atoms in molecules, natural bond orbital, the density of states and frontier molecular orbital analyses were used. The obtained results of the complexation process reveal that morphine@HO-CB[8] complexes are more favorable than other complexes. Moreover, dispersion interactions and hydrogen bond formation were investigated as the driving forces in the host-guest complex formation.

Keywords