Green synthesis of Zinc oxide nanoparticles using Ocimum sanctum leaf extract for biomedical applications

Abstract

Nanotechnology has ignited possibilities for researchers in various fields of physics, chemistry, biology. Nowadays, nanoparticles (NPs) due to their unique electrical, chemical, biological, properties, are profusely used in pharmaceutics, medicinal chemistry, biological and biomedical applications. The unusual properties of nanoparticles are attributed to their minuscule size (one of its dimensions in the size range of 1 to 100 nm) and large surface to volume ratio. There are various nanomaterials that occur naturally, but nanoparticles of particular interest are engineered and designed. These engineered nanoparticles are already being used in various commercial products and processes. A green technology based synthesis of nanoparticles is an eco-friendly, simple, less time absorbing, and cost-effective way to fabricate nanoparticles. The primary aim of this study is to produce Zinc Oxide NPs (ZnONPs) with a facile and green chemistry-based approach using leaf extract of an aromatic perennial plant, Ocimum sanctum, commonly known as tulsi. The particles obtained by the green synthesis route are non-toxic and their surface is free from any toxic chemical impurity. Properties like structural, optical, and morphological of green synthesized ZnONPs were determined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-VIS absorption spectroscopy, and Field emission scanning electron microscopy (FESEM) techniques. The XRD analysis depicts that nanoparticles are pure and crystalline in nature. The result also suggested that this green synthesis technique is effective and led to the production of single phased ZnO nanoparticles. Electron microscopic images estimated the size of the synthesized nanoparticles. The measured FTIR spectra revealed that the functional groups present in plant extract were used for capping and stabilizing the synthesized nanoparticles. The 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyl tetrazolium bromide (MTT) assay was performed on HeLa cell line. This shows that the synthesized ZnO nanoparticles are biocompatible and harmless for cells. The results suggest that these green synthesized ZnO nanoparticles can be used for biomedical applications. Keywords: Nanotechnology, pharmaceutics, green synthesis, ZnO nanoparticles, biocompatible.