Strong Raman enhancement contributed by "hot spots" in directly fused gold dimers offer a selective and sensitive tool for understanding the surface processes involved in the silver staining of gold nanostructures. These processes include the interactions of cations, effects of surface adsorbed Cl- ions, surface replacement of ligands, and reduction of silver ions on the surface of the gold nanocrystals. Results show that in the commonly applied silver staining scheme for gold nanostructures, i.e., the addition of the Raman probe after the deposition of the silver shell, the Raman signals of the probe (p-mercaptobenzoic acid) were weakened greatly, due to the pre-existence of the Cl--Ag+-citrate bridges on the surface of the gold. A new scheme was developed for silver deposition after pre-adsorption of the probe, which achieved a Raman enhancement factor as high as similar to 5 x 10(8).
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机译：强拉曼增强由“热在直接熔融金二聚体提供一个点”选择性和敏感的工具的理解银的表面过程染色的金纳米结构。包括阳离子的相互作用的影响表面吸附Cl -离子,表面替换配体和银离子的还原金纳米晶表面。在一般应用银染色金纳米结构方案,即沉积后的拉曼探针银壳,拉曼信号的探测器(p-mercaptobenzoic酸)被削弱很大程度上,由于预先存在的Cl - Ag) +柠檬酸桥梁表面的黄金。沉积pre-adsorption调查后,实现拉曼增强因子为高吗类似于5 x 10(8)。
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