Shape and SPR Evolution of Thorny Gold Nanoparticles Promoted by Silver Ions

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• 作者：Hong Yuan ; Wanhong Ma ; Chuncheng Chen ; Jincai Zhao ; Jiangwen Liu ; Huaiyong Zhu ; Xueping Gao
• 刊名：Chemistry of Materials
• 出版年：2007
• 出版时间：April 3, 2007
• 年：2007
• 卷：19
• 期：7
• 页码：1592 - 1600
• 全文大小：609K
• 年卷期：v.19,no.7(April 3, 2007)
• ISSN：1520-5002

文摘

The gold-seed-mediated growth approach is developed to obtain three-dimensional (3D) thorny goldnanoparticles, and their morphology can be tailored by introducing different amounts of Ag⁺ ions intothe reaction systems of HAuCl₄ and NH₂OH in the absence of templates and surfactants. Changing theconcentration of silver ions from 0 to 2.5 × 10^-6 M leads to the gradual deviations of the resultednanoparticle morphology from the spherical geometry. The morphology of gold nanoparticles can betuned from sphere to the anomalous nonspheres, to the gold nanoparticles with short thorns, to the goldnanoparticles with long thorns of more than 100 nm. At too high concentrations (above 2.5 × 10^-6 M),the number of the nanothorns on each gold nanoparticle decreased and the central parts of the 3D goldnanostructures (the body) expanded. For the gold nanoparticles with short thorns, most of the short thornsare single crystals and the rest are 2- or 5-fold twinned crystals. However, the long gold thorns consistmainly of 2-fold twinned crystals and a few 5-fold twinned crystals. The 3D thorny gold nanoparticlesexhibit a broad absorption peak at 600-1100 nm in the visible and near-infrared range, and their spectralproperties can be tuned by altering their shapes. These 3D thorny gold nanoparticles have great potentialfor the applications in chemical imaging and biomedical sciences.