Green Synthesis, Characterization, and Antibacterial Activity of CuO/ZnO Nanocomposite Using Zingiber officinale Rhizome Extract

Abstract

The synthesis of metal oxide nanocomposite by using the green method has gotten special consideration due to a cheaper and eco-friendly approach. Decreasing antibiotic effectiveness calls for the fast advancement of other alternative antimicrobials. CuO, ZnO, and CuO/ZnO nanocomposites were successfully synthesized using Zingiber officinale rhizome extract as a mild, renewable, and nontoxic reducing agent and proficient stabilizer with the nonappearance of hazardous and toxic chemicals. UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) were used to characterize CuO, ZnO, and CuO/ZnO nanocomposites. The UV-Visible result showed the absorbance peak at 270 nm, 355 nm, 365 nm, and 370 nm corresponding to the characteristic band of CuO NPs, ZnO NPs, 10% CuO/ZnO, and 20% CuO/ZnO nanocomposites, respectively. FT-IR confirmed the nature of bonds and the presence of different functional groups in the Zingiber officinale rhizome extract, CuO, ZnO, and CuO/ZnO nanocomposites. The XRD analysis revealed that all the synthesized particles have a crystalline nature with a particle size of 4.35 nm, 14.54 nm, 18.41 nm, and 20.50 nm of CuO NPs, ZnO NPs, 10% CuO/ZnO, and 20% CuO/ZnO NCs, respectively. The synthesized nanoparticles and nanocomposites showed inhibition against Gram-positive and Gram-negative bacteria up to a concentration of 12.5 mg/mL. The highest inhibition against Staphylococcus aureus ATCC 25926 and Escherichia coli ATCC was 20 ± 0.7 mm and 16 ± 0.5 mm in diameter, respectively, by 50 mg/mL of 20% CuO/ZnO NCs. In general, the biosynthesized nanoparticles and nanocomposites showed effective antibacterial activity.