Synthesis of gold nanoparticles capped with constituents of some medicinal plants and its biological activity

Abstract

Gold nanoparticles show brilliant colors due to the surface plasmon resonance absorption. The examination of the surface plasmon resonance absorption is part of a large ongoing research field to investigate properties on the nanometer scale. The color of metal nanoparticles is found to depend on the shape and size of the nanoparticle and dielectric constant of the surrounding medium, leading to many studies on their synthesis and applications. Chemical reduction, photochemical reduction, electrochemical reduction, heat evaporation etc. chemical and physical methods are used for NPs synthesis, which are not environmentally friendly. This study interested in bio-synthesis of gold nanoparticles, AuNPs and using the synthesized nanogold as antimicrobial agent.

This study is divided into four chapters Chapter one: Introduction and literature review: This chapter includes a general introduction on nanoparticles and nanotechnology. The chemical and biological methods especially the methods using plant extract for preparations are reviewed.

Chapter two: This chapter includes the different experimental techniques that have been employed to charctarize gold nanoparticles that prepared using some medicinal plants. In this chapter, samples prepration for antimicrobial assay was discussed.

Chapter three: This chapter includes the biosynthesis of nanogold using Rhus coriaria L. fruit extract as a source of reducing agent (antioxidant) capable of converting Au3+ to Au0 nanoparticles. This plant extract has been chosen because of its value in the medicinal applications. Unlike chemical protocols, which demands expensive instruments and results in release of inimical chemicals, biological method is more facile, eco-friendly and results in more monodispersed nanopartic