Praharaj Snigdhamayee, Ghosh Sujit Kumar, Nath Sudip, Kundu Subrata, Panigrahi Sudipa, Basu Soumen, Pal Tarasankar
Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
J Phys Chem B. 2005 Jul 14;109(27):13166-74. doi: 10.1021/jp051132n.
Gold nanoparticles of variable sizes have been synthesized in toluene employing two-phase (water-toluene) extraction of AuCl4- followed by its reduction with sodium borohydride in the presence of a series of cationic surfactants of a homologous series having the general formula C(n)TAC. The solubility features of the gold particles in the organic solvent have been accounted qualitatively by calculating the van der Waals interaction potential between the particles. The effect of thermal energy and medium dielectric constant on the stability of metal particles has been studied by measuring the surface plasmon resonance. The stabilization of surfactant-mediated gold particles as hydrosol or organosol has been elucidated by considering the double-layer interaction as a function of the dielectric constant of the solvent medium. The influence of the counterion of the phase transfer reagent and stabilizing ligand on the photochemical stability of the gold colloids has been investigated. The fluorescence probe 1-methylaminopyrene (MAP) was considered for the surface functionalization of the gold particles, and it has been found that there is an enhancement of molecular fluorescence from the gold-probe assembly.
通过采用AuCl4-的两相（水-甲苯）萃取，随后在一系列通式为C(n)TAC的同系阳离子表面活性剂存在下用硼氢化钠将其还原，在甲苯中合成了尺寸可变的金纳米颗粒。通过计算颗粒间的范德华相互作用势，定性地解释了金颗粒在有机溶剂中的溶解特性。通过测量表面等离子体共振，研究了热能和介质介电常数对金属颗粒稳定性的影响。通过将双层相互作用视为溶剂介质介电常数的函数，阐明了表面活性剂介导的金颗粒作为水溶胶或有机溶胶的稳定性。研究了相转移试剂和稳定配体的抗衡离子对金胶体光化学稳定性的影响。考虑将荧光探针1-甲基氨基芘（MAP）用于金颗粒的表面功能化，并且发现金-探针组装体的分子荧光增强。
