Green Synthesis and Biological Activities of Zinc Oxide Nanoparticles using Ampelocissus martini Rhizome Extract

Zinc oxide nanoparticles (ZnO NPs) were prepared by co-precipitation of zinc acetate with Ampelocissus martini rhizome extract (AM). Four conformations of ZnO NPs were obtained by conjoined precipitation of sodium hydroxide, zinc acetate dihydrate, and AM: ZnO NPs-01, ZnO NPs-02, ZnO NPs-03, and ZnO NPs-04. The structure of ZnO NPs was confirmed by X-Ray diffraction (XRD). Fourier transform infrared (FTIR) analysis was conducted to identify functional groups. The formation and morphology of the synthesized ZnO NPs were confirmed by field emission scanning electron microscopy (FE-SEM) with Energy dispersive X-ray spectroscopy (EDS) mapping, and transmission electron microscopy (TEM). Free radical scavenging activity was determined by 2,2-diphenyl-1-picryl-hydazyl-hydrate (DPPH) and 2,2/-azino-bis-(3-ethylbenzothi-azoline-6-sulfonic acid (ABTS) assays. Antibacterial activity was examined by disc diffusion analysis together with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). ZnO NPs-04 showed the highest inhibition in DPPH and ABTS assays and was active against E. coli and S. aureus with MICs=10 mg/mL and 5 mg/mL, respectively. These findings indicated that synthesized NPs could be utilized for several medicinal applications.