ZnO Nanoparticles Synthesized using Aerial Extract of Ranunculus multifidus Plant: Antibacterial and Antioxidant Activity

The present work reports the synthesis of zinc oxide nanoparticles (ZnO NPs) by applying an aqueous aerial extract of Ranunculus multifidus plant. The thermogravimetric analysis revealed that the prepared ZnO NPs are stable from 480 to 800°C. The diffraction study confirmed the hexagonal wurtzite structure for the synthesized ZnO NPs with the typical crystallite sizes of 47.92, 22.70, and 15.35 nm the volume ratios (extract to precursor) of 1 : 1, 3 : 2, and 2 : 3, respectively. The experimentally deduced Eg values are 1.82, 3.1, and 2.57 eV for 1 : 1, 3 : 2, and 2 : 3 ZnO NPs, respectively. The spherical and rod-like morphologies were confirmed for the NPs by the images taken using electron microscopy. The reducing agents in the aqueous extracts of R. multifidus converted the ionic zinc to zinc nanoparticles, and these NPs exhibit credible antibacterial effects against tested bacterial species. The biosynthesized ZnO NPs revealed significant antibacterial activity against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The order of the antibacterial potential of the NPs was found to follow the order: S. aureus (17.10 ± 0.45 mm) > B. subtilis (16.10 ± 0.15 mm) > E. coli (14.5 ± 0.32 mm) > P. aeruginosa (13 ± 0.0 mm). The antioxidant activities of the produced ZnO NPs in various ratios showed the potentiality of phytochemicals to scavenge the free radicals, which is encouraging for the discovery of novel compounds for the treatment of cancer diseases.