A Review on Biosynthesis of Metal Nanoparticles

By Venkata Ramana Mulpuri and Anuradha Guttula

This book presents a brief review on the biosynthesis of metal nanoparticles using biosynthesis method. Extension review has been carried out and presented in this book. The importance of nanoparticle synthesis and their usage in the medical and industrial applications has been the point of inspiration for the present work. It is strongly felt that the present work saves huge amount of time for the new entrants in this area.

• Language: English
• Publisher: Lulu.com
• Release date: Jul 3, 2014
• ISBN: 9781312326897

Book preview

A Review on Biosynthesis of Metal Nanoparticles

A Review on  Biosynthesis of Metal Nanoparticles

Introduction

The use of plant systems has been considered a green route and a reliable method for the biosynthesis of nanoparticles¹, ². It is evidential from the earlier reports that the plants have been exploited successfully for rapid and extracellular biosynthesis of noble metal nanoparticles³, ⁴, ⁵, ⁶.  Shankar et al⁷, ⁸ reported that gold and silver nanoparticles can be synthesized using plant extracts at a faster rate compared to that of chemical methods.  The leaf extracts of several plants, viz. Lemongrass, Neem, tamarind, Geranium, and Aloe vera, have been reported their potential in reducing Au (III) ions into gold nanoparticles as well as converting silver ions into silver nanoparticles⁷, ⁹, ¹⁰, ¹¹. Similarly, synthesis of platinum and palladium nanoparticles have been reported using extracts of various parts of different plant species¹², ¹³, ¹⁴, ¹⁵. The recent reports on phytosynthesis of nobel metal nanoparticles have been summarized and are discussed below.

Silver Nanoparticles.

Silver has been recognized for its inhibitory effect toward various microorganisms commonly present in medical and industrial processes¹⁶. Among biological processes, phytosynthesis of silver nanoparticles has shown an easier method than the tedious and time-consuming microbial synthesis processes. For instance, parts of plants or their extracts have been explored for the purpose of silver nanoparticles synthesis using silver ions as substrates. The first report of the plant employed in the synthesis of nanoparticles is attributed to Medicago sativa (alfalfa) which was capable of synthesizing gold and silver nanoparticles¹⁷. Since then, more attention has been scattered on plants. Shankar et al⁸ reported the synthesis of highly stable and crystalline silver nanoparticles (16−40 nm) by exposing the aqueous Geranium leaf extract to silver nitrate solution. The rate of synthesis of nanoparticles was found to be very high during the reaction (reaction time 60 min). Later, the same research group reported highly concentrated silver nanoparticles obtained from the aqueous leaf extract of Azadirachta indica as well as from the fruit extract of Embalica officinalis of size 10-20 nm⁴, ¹⁰. Chandran et al¹¹ and Li et al¹⁸ reported the synthesis of silver nanoparticles from the leaf extracts of Aloe vera and Capsicum annum plants, respectively. Leela et al¹⁹ performed an interesting experiment using the leaf extracts of plants, namely, Helianthus annus, Basella alba, Oryza sativa, Saccharum officinarum, Sorghum bicolar and Zea mays, and concluded that among all the tested plant extracts, H. annus exhibited the strongest potential for rapid reduction of silver ions. Farooqui et al²⁰ describes the first report on the synthesis of silver nanoparticles using extracts of a medicinal leaf Clerodendrum inerme from three different leaf conditions – fresh leaves, sun-dried leaves, and hot-air oven dried leaves. Atomic force microscopy (AFM) analysis of the nanoparticles revealed nanoparticles synthesized using fresh leaves possess the smallest size. Rajani et al²¹ reported the fabrication of biogenic Silver Nanoparticles using agricultural plant leaf extracts. Three pulse and cereal crop plants (Vigna radiata, Arachis hypogaea, Cyamopsis tetragonolobus, Zea mays, Pennisetum glaucum, Sorghum vulgare) were used and compared for their extra cellular synthesis of metallic silver nanoparticles. Jain et al²²demonstrated the rapid synthesis of silver nanoparticles, using the fruit extract of Carica papaya, of size 15 nm with cubic structure and reported their anti bacterial activity. Similarly, Cinnamon zeylanicum²³ bark extract mediated synthesis resulted in cubic and hexagonal silver nanocrystals with size ranging between 31–40 nm. Begum et al²⁴ reported rapid synthesis of stable silver nanoparticles of various shapes using black tea leaf extract. Extracellular synthesis of silver nanoparticles has been reported using leaf extract of Pinus desiflora , Diopyros kaki, Ginkgo biloba , Magnolia kobus and Platanus orientalis. These plants were capable of producing stable silver nanoparticles with average particle size ranging from 15 to 500 nm. Further they reported the increased temperature levels allowed nanoparticle growth at a faster rate²⁵. In addition, silver nanoparticles were successfully synthesized using the latex and seed extract of Jatropha curcas with size 10-20 nm and 15-50 nm