Biosynthesis of Nanoparticles

Biosynthesis of nanoparticles is reviewed in detail in this study. Comparison of different synthesis methods, namely physical, chemical and green methods giving emphasis to biological synthesis is documented here. This study also details limitations of the present techniques and envisages the future scope of nanoparticle biosynthesis. Important applications of nanoparticles are also discussed briefly in the present report. INTRODUCTION: Nanotechnology has started leaving conforms of laboratory and conquering the new application to change our lives. The increased surfaces of these nanoparticles are responsible for their different chemical, optical, mechanical, megnatic properties as compared to large bulk materials . Nanoparticles were used by the artisans of Mesopotamia to generate glittering effects to pots. The properties of nanoparticles were proved in 1857 in Faraday’s famous paper “Experimental relations of gold (and other metals) to light” . Due to incredible properties nanoparticles have become significant in many fields in the recent years, such as energy, health care, environment, agriculture, etc. The preparation of nanoparticles are carried out either by (i) Nanoparticles synthesis or by (ii) Processing of nanomaterials into nanostructure particles . The silver nanoparticles are prepared by using physical, chemical and biological methods . The physical and chemical methods are very expensive . Biological methods of nanoparticles synthesis would help to remove harsh processing conditions by enabling the synthesis at physiological pH, temperature, pressure, and at the same time at lower cost. Large number of micro organisms have been found capable of synthesizing inorganic nanoparticles composite either intra or extracellularly . In view of all these, a detail survey of available literature for various biosynthesis methods, their corresponding merits and demerits, numerous applications of silver nanoparticles and future aspects of synthesis and applications of nanoparticle are presented in this review. Bio production of Nanoparticles: There are numerous methods available using various approaches including chemical, physical, and biological protocols for the synthesis of nanoparticles. Chemical method of synthesis is advantageous as it takes short period of time for synthesis of large quantity of nanoparticles. However, in this method capping agents are required for size stabilization of the nanoparticles. Moreover, chemicals reagents used generally for nanoparticles synthesis and stabilization are toxic and lead to