01762nas a2200205   4500008004100000022001400041245007300055210006900128260011000197300001400307490000700321520099400328100001801322700001901340700002501359700001901384700001901403700003001422856010401452       2007                        eng d  a0959-942800aEffect of halogen addition to monolayer protected gold nanoparticles0 aEffect of halogen addition to monolayer protected gold nanoparti  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a1614-16190 v173 a<p>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.</p>1 aSingh, Sanjay1 aPasricha, Renu1 aBhatta, Umananda, M.1 aSatyam, P., V.1 aSastry, Murali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/effect-halogen-addition-monolayer-protected-gold-nanoparticles-001714nas a2200205   4500008004100000022001400041245005700055210005600112260011000168300001400278490000700292520099100299100001801290700002501308700001901333700001701352700001901369700003001388856009001418       2008                        eng d  a0959-942800aBacterial synthesis of silicon/silica nanocomposites0 aBacterial synthesis of siliconsilica nanocomposites  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR  a2601-26060 v183 a<p>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.</p>1 aSingh, Sanjay1 aBhatta, Umananda, M.1 aSatyam, P., V.1 aDhawan, Alok1 aSastry, Murali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/bacterial-synthesis-siliconsilica-nanocomposites-0