Green synthesis of zinc oxide nanoparticles usilng leave extract of Mangifera indica L. and evaluation of its antibacterial activity
Sushma Khatri & Dharma Prasad Khanal

Abstract
The aim of the research study was synthesis of zinc oxide nanoparticles using leaves extract of Mangifera indica L and evaluation of its antibacterial activity. The zinc nanoparticles were synthesized using leaves extract of Mangifera indica L. mixed with zinc acetate. The characterization was done using UV-Visible spectroscopy, FTIR and XRD analysis. Anti-bacterial activity of both extract and the synthesized nanoparticles were evaluated using Agar well diffusion method. The characterization of the synthesized zinc nanoparticles was done by using UV-Visible spectroscopy which exhibited an optical property as indicated by the surface plasmon resonance at 350nm. FTIR analysis shows the essential functional groups as phenols, carbonyl, alcohol and alkane. The XRD analysis was used to calculate the size of zinc nanoparticle and the average size was found to be 11.68nm. The antibacterial activity of synthesized zinc nanoparticle showed improved sensitivity towards both the gram positive and gram-negative bacteria in comparison to plain extract. The study shows that the zinc nanoparticles of leaves extract of Mangifera indica Linn is worth to synthesize. The synthesized nanoparticle possesses promising anti-bacterial activity than plain extract. The synthesis of nanoparticle using the plant source is environment friendly, cost-effective and safer. 

Keywords: Mangifera indica Linn, zinc nanoparticles, UV-Visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), antibacterial activity.