Green synthesis of zinc oxide nanoparticles using flower extract of Nyctanthes arbor-tristis and their antifungal activity

Biological reduction agents are being explored worldwide to minimize the effects of toxic chemicals used in nanoparticle fabrication. The present study states a green approach for the synthesis of zinc oxide nanoparticles employing aqueous flower extract of Nyctanthes arbor-tristis. Flower extract was used as the biological reduction agent for synthesizing zinc oxide nanoparticles from zinc acetate dihydrate. Synthesis conditions were optimized for maximal and narrow size range synthesis of zinc oxide nanoparticles. The resultant nanopowder was characterized using various analytical techniques, such as UV–Visible spectroscopy, Fourier Transform Infrared spectroscopy, X-ray diffraction, Dynamic Light Scattering and Transmission Electron Microscopy. The nanopowder was stored in dried form and was found to be stable after 4 months. The size range of nanoparticles obtained upon synthesis at optimum conditions was 12–32 nm as reported by TEM. X-ray diffraction studies confirmed the crystalline nature of the nanoparticles indicating particle size within the range provided by electron microscopy data. Nanoparticles were tested for their antifungal potential and were found to be active against all five tested phytopathogens with lowest MIC value recorded as 16 μg/mL. Hence, an easy and effective green approach for synthesis of zinc oxide nanoparticles, with efficient antifungal potential is reported in this study. Keywords: Zinc oxide, Phytosynthesis, Electron microscopy, Optical techniques, Flower extract, Antifungal activity