The Biological Activity of Green Synthesis ZnO nanoparticles by Citrus Sinensis Fruit Peels against Staphylococcus aureus Isolated from Skin Infections

Abstract

In this study, a green biological method was used to manufacture zinc oxide nanoparticles (ZnO NPs) from zinc nitrate as a precursor with an aqueous extract of Citrus sinensis fruit peels as reducing agents, and the color changed from yellow to brown, which indicates the production of ZnO NPs. The produced ZnO-NPs were characterizing via X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV-Vis), and Atomic force -Microscopy (AFM). The synthesized ZnO-NPs have been characterized by the XRD peaks confirmed that the ZnO-NPs are hexagonal, and their purity and crystallinity are very high, with an average particle size of 16.21 nm. FTIR analysis was carried out to identify possible bio-molecules responsible for the bio-reduction of zinc ions. Moreover, the surface plasmon resonance (SPR) measured at λmax = 378 nm, confirming the formation of ZnO-NPs. AEM images showed that ZnO-NPs have cubic morphology with sizes ranging from 50 nm. Staphylococcus aureus showed high resistance against Norfloxacin, Trimethprim, Ciprofloxacin, Levofloxacin, Clindamycin and Nirofuranation. The antibacterial effects of particles were investigated by agar well diffusion method with four concentrations of ZnO NPs (25,50,100,200) mg/ml. The ZnO NPs showed the highest diameter of inhibition zone at concentration 200 mg/ml to S.aureus which was 25.5 mm , while the lowest diameter of inhibition zone at concentration (25) mg/ml was 15.4 mm. The minimum inhibitory concentration (MIC) of ZnO NPs was determined using a broth microdilution assay, which was 10.000 µg/ml on S. aureus isolates.