Antibacterial Activites of the CuO/ZnO Nanocomposite Grown on Silica Extracting from Bagasse Ash

Abstract

Nano-scaled Zinc oxide and Copper oxide semiconductors have been widely used as antibacterial agents because of low cost and non-toxicity, but high agglomeration and high electron-holes recombination rates hinder their performances. In this work, we synthesized silica-supported CuO/ZnO and CuO/ZnO bare nanocomposites by the sol-gel technique. The antibacterial activities of both nanocomposites have compared on Gram-negative (E. coli) and Gram-positive (S. aura) bacteria. The average crystal sizes of CuO/ZnO bare is 16.3 nm, and silica-supported CuO/ZnO is 29.1 nm as calculated from XRD data. Moreover, SEM results showed that there was no agglomeration in silica-supported CuO/ZnO due to the presence of silica. When antibacterial activities of both nanocomposites were tested by using the agar diffusion method, silica-supported CuO/ZnO showed an inhibition zone of 51% for Staphylococcus aureus and 53% for Escherichia coli compared with that of CuO/ZnO bare. Therefore, silica-supported CuO/ZnO nanocomposite is a promising antibacterial agent because of its low cost, non-toxicity, and good antibacterial properties..