Biosynthesis of zinc oxide nanoparticles using Fumaria parviflora extract and evaluation of their antibacterial and antioxidant activities

Green synthesis is a biocompatible and stable method of producing zinc oxide nanoparticles (ZnONPs).In the present study, ZnONPs were biosynthesized using Fumaria parviflora extract by the green method, and the antibacterial and antioxidant properties of these NPs were evaluated. The characteristics of the synthesized ZnONPs were determined by ultraviolet-visible spectrophotometry (UV-VIS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The antioxidant activity of the NPs was tested by the α-diphenyl-β-picrylhydrazyl (DPPH) method. Antibacterial properties of the synthesized ZnONPs were evaluated against Staphylococcus aureus and Escherichia coli by disc diffusion and microdilution methods. The results of UV-VIS spectroscopy revealed an absorption peak at 370 nm. XRD results showed the formation of a hexagonal wurtzite structure, and SEM analyses demonstrated that ZnONPs had a spherical shape with an average size 42 to 60 nm. Free radical scavenging capacity of ZnONPs was assessed using the DPPH assay with varying concentrations of ZnONPs, and scavenging activity was observed with IC50 of 30.86 μg/ml. In the antibacterial assay, the inhibition zone of the synthesized NPs at 100 μg/ml concentration for S. aureus (24.6±0.72) was greater than that of the antibiotics vancomycin (23±0.51) and a mikacin (13±0.40) and was greater for E. coli (13.2±0.81)than that of vancomycin (12±0.41) (P ≤ 0.05). The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of ZnONPs for S. aureus and E. coli were 1.56 and 3.125 μg/ml, and 6.25 and 12.5 μg/ml, respectively. The biosynthesized ZnONPs showed strong antibacterial and antioxidant activities.