Morphological Characterization of Bio-Mediated Silver Nanoparticles from Azadirachta Indica (Neem) Leaf Extract

Abstract

A facile, low cost and environment-friendly synthesis process of nanoparticles is very necessary due to the increasing concern for the environment. In this study, silver nanoparticles (AgNPs) were prepared from silver nitrate precursors using leaves from Azadirachta Indica plant, also referred to as the Neem tree. The presence of phytochemicals (alkaloids, flavonoids, proteins, terpenoids, etc.) in Azadirachta Indica leaf extract was mainly responsible to synthesis AgNPs. For the preparation of Azadirachta Indica leaf extract mediated silver nanoparticles (A.I-AgNPs), the synthesis parameters were chosen for pH 8, time 1.5 hrs, temperature 70ºC, plant extract: silver nitrate 1:8. The as-prepared A.I-AgNPs were characterized by ultraviolet-visible (UV-vis) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) analysis. After the addition of plant extract into the silver nitrate solution, the color of the reaction mixture was changed from yellow to brown to dip brown which was the visual confirmation of silver nanoparticles formation. The surface plasmon resonance (SPR) characteristic of A.I-AgNPs was analyzed by UV–vis spectrophotometer test. The SPR peak was found at 460nm which confirmed the successful formation of silver nanoparticles. The FE-SEM analysis revealed that most of the nanoparticles are spherical in shape with the size ranging from 45nm to 111nm (average 84nm). EDX analysis showed an intense peak at 3KeV that strongly proved the presence of silver elements. FTIR analysis of the synthesized silver nanoparticles confirmed the presence of different functional groups on the A.I-AgNPs surface which ensured the successful reduction and capping of silver nanoparticles. The successful preparation of A.I-AgNPs suggested that the chosen synthesis parameters can be further used to prepare AgNPs for various applications.