Au-Ag三角纳米环单层膜的原位转化制备及SERS效应

Gold-silver Framework Monolayer Nanostructure Prepared by in-situ Sacrificial Template Reaction and Their Application for SERS

利用模板牺牲氧化还原反应将自组装在基片上的三角板银纳米粒子(边长约为79.2nm)与氯金酸溶液作用进而原位转化形成三角纳米环.通过紫外-可见(UV-Vis)光谱实时监测基片上银三角板纳米粒子在反应不同阶段的消光特性;扫描电子显微镜(SEM)显示了银三角板纳米粒子转化过程的形貌变化;利用X射线光电子能谱(XPS)对其成分进行分析.表征结果表明,三角纳米环的成分为Au-Ag合金或复合物;随着基片与氯金酸溶液作用时间的增加,自组装膜的表面等离子体共振峰逐渐红移;Au-Ag三角环状纳米粒子的平均壁厚度从29.3nm缩小至16.2nm.以4-巯基苯胺(4-ATP)为探针分子研究了该Au-Ag三角环状纳米粒子单层膜的表面增强拉曼(SERS)活性.自组装单层膜基底的SERS信号随着Au-Ag三角纳米环平均壁厚度的增加逐渐增强.

A gold-silver nanoframe monolayer nanostructure was obtained on the glass slide using the in-situ sacrificial template reaction. First the silver nanoprisms （-79.2 nm edge length） were prepared as the sacrifi- cial template and were assembled on the slides through electrostatic interactions. The chloroautric acid in-situ reacted with the silver nanoprisms as oxidant. We evaluated the effect of oxidation reaction time on the morphologies and the LSPR properties of the prepared nanoframes. The thickness of gold-silver framework can be adjusted from 29. 3 nm to 16. 2 nm. We applied the gold-silver framework monolayer as a new surface-enhanced Raman scattering（SERS） substrate for determining 4-aminothiophenol.