Study the Nature of the Interaction Between 5-Fluorouracil Anti-cancer Drug and Zinc Oxide Nanocage

We proposed a quantum chemical calculation to investigate the nature of the adsorption of 5-Fluorouracil (5FU) on the zinc oxide (ZnO) nanocage. For this purpose, different geometries of this drug were considered to be adsorbed over the nanocage. The interaction energy is found to be quite favorable when 5FU is adsorbed with its -C = O-component onto the ZnO nanocage, compared to the other sides of the drug. The binding sites for all cases were found to belong to the nanocage in the zinc site. The charge evaluations focusing on the study of the NBO suggested that the charge transfer could be from the 5FU to the ZnO surface. The formation of physical adsorption in the interacting atoms can be further characterized in the interface regions by the density of state diagrams. Based on molecular orbitals, the HOMO is mostly situated on the adsorbed molecules of 5FU, while the electron densities in the LUMOs in the most stable configurations were mainly located on the surface of the nanocage. In another word, the charge transfer has occurred from 5FU to ZnO nanocage. The sensor mechanism is dependent upon the difference between the electronic levels. It also corresponds to the changes in the electrical conductivity. The sensor response was predicted to be approximately 1185 for 5FU detected with the ZnO nanocage, which was in complete agreement with the experimental results.