电荷转移对纳米金属吸附分子拉曼光谱影响

Charge Transfer Contribution to Surface-Enhanced Raman Scattering of Nanoparticles Metal Adsorbed Molecules

在金,银纳米粒子表面修饰对巯基苯胺(PATP)分子,对其进行紫外及拉曼光谱性质表征。紫外吸收光谱显示修饰了单分子层的纳米粒子表面等离子体共振发生较大的红移,银粒子位移程度大于金粒子的。其拉曼散射增强效应研究表明,对巯基苯胺b2振动模式的极大增强是由电磁增强和化学增强效应共同决定的。金、银粒子上对巯基苯胺单分子层拉曼散射增强效应的差异主要来自金属与对巯基苯胺之间电荷转移能力的不同。

The SERS spectra of p-aminothiophenol（PATP）were investigated on silver and gold nanoparticles.Absorption spectra of nanoparticles demonstrated that charge transfer resulted in large shifts of surface plasmon resonance.SERS signal of PATP showed that electromagnetic enhancement and chemical enhancement both contribute to b2 mode enhancement.It was found charge transfer from metal to the surface-adsorbed molecules was more favorable on the silver nanoparticles than that on the gold nanoparticles.This is attributed to the fact that the work function of gold is larger than that of silver.