ABSTRACT

In this study, Zinc oxide Nanoparticles (ZnO NPs) were synthesised using Mango (Mangifera indica) aqueous leaf extract. 0.1 M zinc acetate dihydrate was used as a precursor for Nanoparticles (NPs) synthesis. The structural and optical properties of NPs were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet-visible spectrophotometer (UV-Vis). The antibacterial effect of the biosynthesized ZnO NPs was evaluated using the agar well diffusion assay against Staphylococcus aureus, Bacillus subtilis as gram positive bacteria (GPB), and Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumonia as gram negative bacteria (GNB). The minimum inhibitory concentration (MIC) of the biosynthesized ZnO NPs was determined using the agar dilution method. Change in color of the reaction mixture indicated the formation of ZnO NPs. UV peak at 365 nm and obtained XRD pattern of the biosynthesis ZnO NPs confirmed the presence of pure ZnO NPs. Using Debye-Scherrer’s formula, the average grain size of the synthesised ZnO NPs was found to be 17.2 nm, which indicates that the ZnO NPs are in the nanoscale range. The FTIR spectrum of the synthesised ZnO NPs confirmed the presence of bioactive functional groups involved in the reduction of bulk zinc acetate to ZnO NPs. The M. indica mediated ZnO NPs showed antibacterial activity against the GPB suggesting that biosynthesised ZnO NPs can be an excellent strategy to develop versatile and eco-friendly biomedical products.