Eco Friendly Synthesis of Copper Oxide Nanoparticles from Orange Peel Extract and its Antimicrobial Studies

The synthesis and stabilization of CuONPs at room temperature by using an aqueous extract of orange peel are described. The reason for the appearance of UV-vis absorption spectra peak at (∼439 nm) may be given as the evidence for forming CuONPs. In general, the XRD spectrum of the CuONPs agrees with the previous studies for Cu metal. Transmission Electron Microscopy exhibits irregular crystalline particles. Thus, the average particle size is ∼17 nm. CuONPs have shown potent bactericidal activities. The prepared CuONPs were applied against four pathogenic bacterial strains and three fungal strains as an antimicrobial agent. The inhibition growth zone for Bacillus subtilis and Aspergillus flavus was 18 mm and 19 mm, respectively. The minimum inhibition concentration was 1500 μg/ml for both Staphylococcus aureus and Bacillus subtilis, while their minimum bactericidal effect was 2000 μg/ml and 2500 μg/ml, respectively. For fungal strains, the minimum inhibition concentration for Aspergillus flavus and Aspergillus niger was 3000 μg/ml, while their minimum fungicidal effect was 3500 μg/ml and 4000 μg/ml, respectively. Since the ratio of MIC to MBC or MFC was less than 2, the action mode of CuONPs has been defined as both bactericidal and fungicidal. After all, CuONPs are highly recommended as an effective antimicrobial agent that can be used for pathogen elimination.