Extracellular biosynthesis of silver nanoparticle using Azadirachta indica leaf extract and its anti-microbial activity

Rapid synthesis of silver nanoparticles through economically feasible green chemistry approach is highly desirable. In this study we have developed a method to synthesize silver nanoparticles by mixing silver solution with leaf extract of Azadirachta indica without using any surfactant or external energy. In this method, physiologically stable, bio-compatible Ag nanoparticles were formed. These functionalized AgNPs could be used for targeted drug delivery with enhanced therapeutic efficacy and minimal side effects. Extracellular synthesis of metal nanoparticles using extracts of plants like A. indica (Neem), and Zingiber officinale (Ginger) has been successfully carried out. In this article AgNPs formation using Azadirachta indica has been thoroughly discussed. It is well known that on treating the metallic salt solution with some plant extracts, a rapid reduction occur leading to the formation of highly stable metal nanoparticles. With this method rapid synthesis of nanoparticles was observed to occur; i.e. reaction time was 1-2 h as compared to 2-4 days required by microorganisms. These nanoparticles were analyzed by various characterization techniques to reveal their morphology, chemical composition, and antimicrobial activity. TEM image of these NPs indicated the formation of spherical, non-uniform, poly dispersed nanoparticles. A detailed study of anti-microbial activity of nanoparticles was carried out.