Raman spectroscopy and microscopy based on mechanical force detection
Raman spectroscopy and microscopy based on mechanical force detection
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DOI：
10.1063/1.3652760
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发表时间：
2011-10-17
影响因子：
4
通讯作者：
Wickramasinghe, H. Kumar
中科院分区：
文献类型：
--
作者：
Rajapaksa, I.;Wickramasinghe, H. Kumar
拉曼效应通常是通过用强光源照射样品并检测微小的频移散射光来观察到的。我们证明，拉曼分子的振动共振可以通过一种完全不同的机制--即力测量--直接检测到。我们通过受激拉曼激发的表面分子与悬臂式纳米级探针尖端之间的光学参数下转换来创建力的相互作用。对分子簇进行了光谱分析和显微镜观察。在拉曼显微照片中，这种团簇中的单分子被清楚地分辨出来。这项技术可以很容易地扩展到执行泵浦探测实验，以测量分子间和分子内的耦合以及单分子水平上的构象变化。(C)2011年美国物理研究所。[DOI：10.1063/1.3652760]
The Raman effect is typically observed by irradiating a sample with an intense light source and detecting the minute amount of frequency shifted scattered light. We demonstrate that Raman molecular vibrational resonances can be detected directly through an entirely different mechanism-namely, a force measurement. We create a force interaction through optical parametric down conversion between stimulated, Raman excited, molecules on a surface and a cantilevered nanometer scale probe tip brought very close to it. Spectroscopy and microscopy on clusters of molecules have been performed. Single molecules within such clusters are clearly resolved in the Raman micrographs. The technique can be readily extended to perform pump probe experiments for measuring inter- and intramolecular couplings and conformational changes at the single molecule level. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3652760]