Zinc oxide nanosheet as a promising route for carrier 5-fluorouracil anticancer drug in the presence metal impurities: Insights from DFT calculations

Abstract

Zinc oxide nanosheet (ZnONS) is a favorable road to deliver numerous drug molecules in the human body. The electronic properties of the 5-FU/pristine ZnONS and 5-FU/metal-doped ZnONS are studied by using DFT method, which implemented in the quantum espresso package. Metal impurities are utilized to recognize the suitability and optimization of the adsorption 5-FU on the ZnONS superficial. For metal-doped ZnONS and 5-FU/metal-doped ZnONS, we observed that the shape of the electronic band structure is changed. So, the electronic band gap and Fermi level are reduced and shifted up, respectively compared to the pristine ZnONS, but they still have semiconductor behaviors. Moreover, all complex structures become more stable and lower reactive due to the total energy increased. Results disclosed a weaker interaction between the pristine ZnONS and 5-FU, but there is a stronger interaction between the 5-FU and metal-doped ZnONS. We detected very exciting results. The adsorption process is depended on the type of the impurities and the distance between the 5-FU molecule and metal-doped ZnONS. So, it became stronger when we made the distance between this molecule and metal-doped ZnONS is smaller. Additionally, all structures have a lower and higher electron affinity and chemical hardness, respectively. That means these structures needed a higher energy to donating/accepting an electron to be cation/anion. Besides, there is a great interaction between the pristine ZnONS and 5-FU molecule in the present (Cu, Au, and Ag) impurities between them, but other metal impurities made a weak interaction between them. Then, we can utilize the new substrate (metal-doped ZnONS structures) as a carrier to the 5-FU drug molecule.