Re-examining the origins of spectral blinking in single-molecule and single-nanoparticle SERS
Re-examining the origins of spectral blinking in single-molecule and single-nanoparticle SERS
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DOI：
10.1039/b509223j
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发表时间：
2006-01-01
影响因子：
3.4
通讯作者：
Nie, SM
中科院分区：
文献类型：
--
作者：
Emory, SR;Jensen, RA;Nie, SM
已知单个金属纳米颗粒和纳米聚集体以间歇的开和关方式发射强烈的表面增强拉曼散射（Sers）脉冲。典型的“闪烁”时间尺度从毫秒到秒不等。在这里，我们报告了详细的温度依赖性（加热和冷却）和光强度研究，以进一步研究这种有趣现象的起源。结果表明，闪烁Sers包含热激活成分和光诱导成分。几条线的证据表明，所观察到的波动是由热激活扩散的颗粒表面上的单个分子，再加上光诱导的电子转移和结构松弛的表面活性位点或原子尺度的粗糙度功能。
Single metal nanoparticles and nanoaggregates are known to emit intense bursts of surface-enhanced Raman scattering (SERS) in an intermittent on and off fashion. The characteristic "blinking'' timescales range from milliseconds to seconds. Here we report detailed temperature dependence ( both heating and cooling) and light-intensity studies to further examine the origins of this intriguing phenomenon. The results indicate that blinking SERS contains both a thermo-activated component and a light-induced component. Several lines of evidence suggest that the observed fluctuations are caused by thermally activated diffusion of individual molecules on the particle surface, coupled with photo-induced electron transfer and structural relaxation of surface active sites or atomic-scale roughness features.