GREEN SYNTHESIS OF SILVER NANOPARTICLES USING TULSI LEAF AT DIFFERENT ENVIRONMENTAL CONDITIONS

Abstract

This thesis is based on the use of Tulasi (ocimum sanctum) leaf broth in the synthesis of silver nanoparticles. On treating aqueous solution of silver nitrate with Tulasi leaf extract; a rapid formation of stable silver nanoparticles take place. In this process, aqueous leaf extract of Tulasi was used as capping as well as reducing agent. To characterize the synthesized nanoparticles we have used Scanning Electron Microscopy (SEM), X-ray diffractometry, Fourier Transform Infrared Spectroscopy, Emission and absorption spectroscopy. The synthesized nanoparticles which show a strong absorption and emission bands are crsytalline in nature. The rate of reduction of the metal ions by Tulasi leaf extract are much faster than those observed in earlier studies using micro-organisms such as fungi, demonstrating that synthesis of nanoparticles using biological methodologies can achieve rates of synthesis equivalent to the rates of synthesis of chemical methods. In addition, we have explored the effects of different parameters, such as pH, temperature, concentration on the synthesis of silver nanoparticle by biological methods and we have succeeded to control the size, quality and quantity of nanoparticles.