ZrO2–ZnO Nanoparticles as Antibacterial Agents

Antibiotic resistance by bacteria has continued to prompt research for new agents that can inhibit bacterial growth. Therefore, in this study, we described the synthesis, physicochemical characterization, and the antibacterial activity of pure metal oxide nanoparticles of ZrO 2 and ZnO and the antibacterial activity of their mixed metal oxide of ZrO 2 -ZnO nanoparticles against three Gram-positive of Bacillus subtilis , Streptococcus mutans , Staphylococcus aureus, and 3 Gram-negative of Escherichia coli , Pseudomonas aeruginosa , and Klebsiella oxytoca . The nanoparticles were successfully prepared by sol-gel method and were subsequently characterized using dynamic light scattering analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results obtained from the characterization techniques confirm the formation of ZrO 2 , ZnO, and ZrO 2 -ZnO nanoparticles with diameter sizes of 76, 22, and 26-34 nm, respectively. SEM reveals spherically shaped nanoparticles. The XRD shows the formation of monoclinic zirconia and hexagonal zinc oxide, formation of amorphous compound in Z-Z 0.25 and Z-Z 0.5 while Z-Z 1.0 and Z-Z 2.0 have peaks that corresponds to the diffractogram pattern present in ZrO 2 and ZnO. From the preliminary screening, ZrO 2 and the amorphous particles of Z-Z 0.25 and Z-Z 0.5 did not record any inhibition against any of the test bacteria while ZnO, Z-Z 1.0 , and Z-Z 2.0 recorded inhibition against all the tested bacteria.