Fascinating approach for using metabolites products of living microorganisms as reducing agents for preparing silver nanoparticles

A crucial area of research in nanotechnology is the formation of environmentally benign nanoparticles. Both unicellular and multicellular play an important role in synthesis nanoparticles through the production of inorganic materials either intracellularly or extracellularly. The agents (pigments, siderophores, cell extracted metabolites and reducing compounds) were used to prepare silver nanparticles with different sizes and shapes. The color variations (dark yellow, slightly dark yellow and golden yellow) arising from changes in the composition, size, and shape of nanoparticles, surrounding medium can be monitored using UV-visible spectrophotometer. These effects are due to the phenomena called surface plasmon resonance. The silver nanoparticles have Plasmon resonances ranged between (390, 383 and 365) nm which they are among the limitation of silver nanoparticles (360 – 420 nm). AFM analysis of Ag NP's showed partially purified big triangular Ag NP having edge length around ~1. mm. Hexagonal particles on the background of a matrix made up of some molecules which may be metabolites products are found. Small spherical nanoparticles embedded in some kind of matrix indicate that this molecule acts as capping agent, which inhibits further growth of nanoparticles. Also ribbons like structures of width around 50 nm which are intertwined are the noble and rare structures which are synthesized by this method. MIC of silver Nanoparticles for. E coli, ranges between 80-90 µg/ml.., Serrtia, ranges between 50-60 µg/ml and Shagilla, ranges between 90-100 µg/ml.