ABSTRACT
Nanotechnology is the application of science to control matter at the molecular level. A nanometer (nm) is one billionth of a meter, or roughly the length of three atoms side by side. A nanoparticle is a microscopic particle with atleast one dimension less than 100 nm. The applilcation of nanoscale materials and structures, usually ranging from 1 to 100 nanometer are an emerging area of nanoscience and nanotechnology. Gold nanoparticles, in particular, are of interest, due to their stability under atmospheric conditions, resistance to oxidation and biocompatibility. Microorganisms as possible eco–friendly nanofactories can exert control over size, morphology, composition and crystallographic orientation of the as–prepared metal nanostructured particles. In the area of nanotechnology, the development of techniques for the controlled synthesis of metal nanoparticles of well defined size, shape and composition is a big challenge. This work was highly focused on the Gold nanoparticles production from Pseudomonas sp. and concentrating the work towards the production at controlled size by means of various parameter optimization studies like pH, temperature and concentration. The optimization work was characterized by means of TEM. With the results of TEM, the small sized nanoparticle of about 10nm was observed at pH of 9 and 12nm was produced at the pH of 3. Low temperature of 25oC favored the small size nanoparticle at a concentration of 250 mg/l using HAuCl4.