@article { ISI:000257271600057, title = {Bacterial synthesis of copper/copper oxide nanoparticles}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {8}, number = {6}, year = {2008}, month = {JUN}, pages = {3191-3196}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

A bacterial mediated synthesis of copper/copper oxide nanoparticle composite is reported. A Gram-negative bacterium belonging to the genus Serratia was isolated from the midgut of Stibara sp., an insect of the Cerambycidae family of beetles found in the Northwestern Ghats of India. This is a unique bacterium that is quite specific for the synthesis of copper oxide nanoparticles as several other strains isolated from the same insect and common Indian mosquitoes did not result in nanoparticle formation. By following the reaction systematically, we could delineate that the nanoparticle formation occurs intracellularly. However, the process results in the killing of bacterial cells. Subsequently the nanoparticles leak out as the cell wall disintegrates. The nanoparticles formed are thoroughly characterized by UV-Vis, TEM, XRD, XPS and FTIR studies.

}, keywords = {bacterial synthesis, Nanoparticles, TEM, XPS, XRD}, issn = {1533-4880}, doi = {10.1166/jnn.2008.095}, author = {Hasan, Syed Saif and Singh, Sanjay and Parikh, Rasesh Y. and Dharne, Mahesh S. and Patole, Milind S. and Bhagavatula L. V. Prasad and Shouche, Yogesh S.} } @article { ISI:000256073500012, title = {Bacterial synthesis of silicon/silica nanocomposites}, journal = {Journal of Materials Chemistry}, volume = {18}, number = {22}, year = {2008}, month = {APR}, pages = {2601-2606}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

The synthesis of silicon/silica nanoparticle composites by the bacterium Actinobacter sp. is demonstrated. More specifically, the formation of silicon/silica nanocomposite is shown to occur when the bacterium is exposed to K(2)SiF(6) precursor under ambient conditions. Based on the earlier reports where this bacterium has been shown to synthesize iron oxide and iron sulfide nanoparticles, it is hypothesized that this bacterium secretes reductases and oxidising enzymes, which lead to the Si/SiO(2) nanocomposite synthesis. The particles obtained by bacterial synthesis were thoroughly characterized. The cytotoxicity studies revealed that the particles do not display any cytotoxicity to human skin cells. The synthesis of silica nanoparticles by bacteria in the present study demonstrates the versatility of the organism, and the formation of elemental silicon by this environmentally friendly process expands further the scope of microorganism based nanomaterial synthesis.

}, issn = {0959-9428}, doi = {10.1039/b719528a}, author = {Singh, Sanjay and Bhatta, Umananda M. and Satyam, P. V. and Dhawan, Alok and Sastry, Murali and Bhagavatula L. V. Prasad} } @article {42680, title = {Bacterial synthesis of phtocatalytically active and biocompatible TiO2 and ZnO nanoparticles}, journal = {International Journal of Green Nanotechnology: Physics and Chemistry}, volume = {2}, year = {2010}, month = {DEC}, pages = {80-99}, abstract = {

TiO2 and ZnO nanoparticles are well known for their photocatalytic and ultraviolet (UV)-absorbent properties and have successfully entered into the market as consumer products. Large volume production of these nanoparticles by industries require environmentally friendly processes of synthesis. In this article, we show that when challenged with an appropriate precursor, the bacterium Actinobacter spp. can lead to the extracellular synthesis of ZnO and TiO2 nanoparticles. The biological way of synthesizing these materials probably leads to the in situ doping of elements like C, F, and N into their crystal lattices, which is evidenced by a red shift in the absorption edge. Because the doping is expected to affect the photocatalytic activity of these materials under different light conditions, such investigations have also been undertaken here. Further, the biocompatibility of these nanomaterials (cytotoxicity and genotoxicity) has also been investigated in detail.

}, keywords = {Biosynthesis, genotoxicity, Nanoparticles, Nanotoxicity, Photocatalysis}, doi = {10.1080/19430876.2010.532459}, author = {Singh, Sanjay and Britto, Virginia D. and Bharde, Atul A. and Sastry, Murali and Dhawan, Alok and Bhagavatula L. V. Prasad} }