Biosynthesis of Zinc Oxide Nanoparticles Using Solenostemon Monostachyus Leaf Extract and its Antimicrobial Activity

Abstract

A simple and rapid biosynthesis of zinc oxide nanoparticles (ZnO NPs) obtained using Solenostemon monostachyus leaf extract. The ZnO NPs was characterised by UV-visible spectroscopy, scanning electron microscopy/Energy dispersed X-ray, Fourier Transform Infra-red and X-ray Diffraction techniques. The UV-visible spectrum showed a maximum absorption peak at 350 nm which is typical for ZnO NPs and was ascribed to the excitation of Surface Plasmon Resonance phenomenon. FTIR Spectroscopy revealed a broad peak around 3455 cm^-1 which was attributed to OH stretching vibration (υOH) that is probably from alcohols, flavonoids and phenols. X-ray Diffraction studies were observed at 2θ = 11.1°, 13.8°, 16.7°, 25.1°, 28.9° and 44.0°. The X-ray spectrum indicated typical for crystalline nanoparticles. Calculated nano particle size was 23.06 nm and was within the literature range for nano zinc oxide. The synthesized NPs exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus but exhibited moderate activity against Klebsiella pneumonia and Salmonella typhimurium. Significant antifungal activity was also observed against Aspergellus niger and Candida albican.