Green synthesis of silver nanoparticles using plant extracts

The strategy for design of new nanometals was developed due to their wide applications in many fields. One of the most important nanometals is silver nanoparticles (AgNPs) because of their extensive applications in biotechnology and biomedical fields. AgNPs were usually synthesized by using chemical and physical methods. In the chemical methods, various toxic chemicals are used, which are harmful to the health of living organisms. Therefore, the AgNPs were synthesized by using biological methods based on green chemistry for reducing the toxic chemicals. There are various resources for green synthesis of AgNPs, such as bacteria, fungi, enzyme and plant extracts. The green synthesis of AgNPs involves three main steps: the selection of the solvent medium, the selection of environmentally reducing agents, and the selection of non-toxic substances for the stability of AgNPs. The biosynthesis of AgNPs using plant extracts is more favorable than other biological methods because of removing the elaborate process of maintaining cell cultures. It can be also suitably scaled up for large scale production of AgNPs. This review focuses on green synthesis of AgNPs using various plant extracts.