Biosynthesis of Zinc Oxide Nanoparticles Using Ficus racemose Leaf Extract via Microwave Irradiation Route: Characterization and Investigation of Antibacterial Efficacy

Abstract

The present study reports a cost-effective and eco-friendly route for the one-pot biogenic synthesis of zinc oxide (ZnO) nanoparticles (ZnO NPs) using Ficus racemose leaf extract. The average particle size distribution and zeta potential were reported as 200 nm and −10.47 mV via dynamic light scattering (DLS) and zeta potential. The single-phase patterns of ZnO NPs showing hexagonal crystal structure with an average crystallite size of 21 nm were measured via X-ray diffraction (XRD). Field emission scanning electron microscopy (FESEM) revealed the cubical and cuboidal morphology of NPs with an average size of 95–220. In contrast, transmission electron microscopy (TEM) and selective area electron diffraction (SAED) revealed the d-spacing value as 0.247 to confirm the formation of ZnO NPs. The maximum wavelength for ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy were observed at 355 nm and 556 nm, respectively. Functional groups containing flavonoids and polyphenols as reducing agents for the reduction and synthesis of ZnO NPs were verified through Fourier transform infrared (FTIR) spectroscopy. ZnO NPs were also evaluated for their strong antibacterial property against Staphylococcus aureus (12 ± 0.69 mm) and Escherichia coli (11 ± 0.83 mm). This can be employed in numerous biological and biomedical domains, such as preventing bacterial growth.