@article { ISI:000232326700015, title = {Porous gold nanospheres by controlled transmetalation reaction: a novel material for application in cell imaging}, journal = {Chemistry of Materials}, volume = {17}, number = {20}, year = {2005}, month = {OCT}, pages = {5000-5005}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Hollow shell nanostructures have numerous potential applications due to their interesting optical and electronic properties, which can be tuned by varying their shape, size, and shell thickness. In this paper we describe a simple galvanic replacement reaction (transmetalation reaction) involving sacrificial silver nanoparticles and Au(III) ions using a dialysis membrane. The dialysis membrane acts as a partial barrier that provides excellent control over the kinetics of reaction. This process results in the formation of porous gold nanospheres that improve the fluorescence in cell staining by offering an enhanced surface area for binding of the fluorescent dye, propidium iodide (PI). Such porous nanostructures could be ideal candidates for applications such as catalysis, enzyme immobilization, and drug delivery.

}, issn = {0897-4756}, doi = {10.1021/cm051165f}, author = {Shukla, Sourabh and Priscilla, Anie and Banerjee, Meenal and Bhonde, Ramesh R. and Ghatak, J. and Satyam, P. V. and Sastry, Murali} } @article { ISI:000245599400011, title = {Effect of halogen addition to monolayer protected gold nanoparticles}, journal = {Journal of Materials Chemistry}, volume = {17}, number = {16}, year = {2007}, month = {FEB}, pages = {1614-1619}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

The effects of N-halosuccinimide and halogen addition to monolayer protected gold nanoparticles (Au NPs) dispersed in organic media are described. Contrary to the expectation that nanoparticles dispersed in organic media are stable against aggregation, N-iodosuccinimide addition induced aggregation of octadecylamine capped gold nanoparticles in chloroform or toluene. It was observed that even KI and CuI addition could bring about the aggregation though they are very sparingly soluble in organic solvents. It was also found that even molecular iodine could bring about the above mentioned aggregation. Interestingly, when CuI is used the aggregated structures readily convert to very thin flat nanostructures upon exposure to an electron beam or UV irradiation. In fact when the aggregation is induced by the addition of KI or N-iodosuccinamide we do not see the flattening of the aggregated structures exemplifying the important role of Cu ions in making these flat structures.

}, issn = {0959-9428}, doi = {10.1039/b614934k}, author = {Singh, Sanjay and Pasricha, Renu and Bhatta, Umananda M. and Satyam, P. V. and Sastry, Murali and Bhagavatula L. V. Prasad} } @article {17}, title = {Interfacial deposition of Ag on Au seeds leading to AucoreAgshell in organic media}, journal = {Journal of Colloid and Interface Science}, volume = {312}, number = {16}, year = {2007}, month = {AUG}, pages = {498-505}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, keywords = {core-shell nanoparticles, Gold, HRTEM, interfacial seeded growth, Silver, XPS}, issn = {0021-9797}, doi = {10.1016/j.jcis.2007.03.032}, author = {Chandran, S. Prathap and Ghatak, J. and Satyam, P. V. and Sastry, Murall} } @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} }