Abstract
Biogenic synthesis of nanoparticles offers an attractive alternate to chemical synthesis methods. Various hazard free, eco-friendly methods of synthesis of silver nanoparticles are in operation. In chemical reduction methods, the reducing agent is a chemical solution, whereas in biological ones, the collection of enzymes, especially nitrate reductase, plays this role. The highest antibacterial activity of silver nanoparticles synthesised by chemical and biological methods was found in Staphylococcus aureus and Escherichia coli. The paper aims to discuss some fundamental issues about non-biological methods and benefits about biological methods for silver nanoparticles synthesis and their antibacterial studies.