Temporal fluctuation of tip-enhanced raman spectra of adenine molecules
Temporal fluctuation of tip-enhanced raman spectra of adenine molecules
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DOI：
10.1021/jp070420b
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发表时间：
2007-06
影响因子：
3.7
通讯作者：
T. Ichimura;H. Watanabe;Y. Morita;P. Verma;S. Kawata;Y. Inouye
中科院分区：
文献类型：
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作者：
T. Ichimura;H. Watanabe;Y. Morita;P. Verma;S. Kawata;Y. Inouye
在腺嘌呤分子的尖端增强拉曼散射（TERS）光谱中观察到光谱形状的时间波动。腺嘌呤分子纳米晶簇的 TERS 光谱显示出明显的时间变化，包括峰频率和峰强度的波动以及几个峰的异常增强。波动的 TERS 信号主要源自 5 nm 厚的腺嘌呤纳米晶体簇第一层中的分子。时间变化的可能起源归因于金属涂层尖端下分子取向的变化，这负责改变吸附到尖端的分子的吸附角和局部入射偏振角。这一结果表明分子水平上样品与尖端相互作用在 TERS 光谱解释中的重要性，并表明 DNA 基础分子的 TERS 光谱单分子敏感性的可能性。
Temporal fluctuations of spectral shapes have been observed in tip-enhanced Raman scattering (TERS) spectra of adenine molecules. The TERS spectra of a nanocrystalline cluster of adenine molecules showed distinct temporal changes including fluctuations of peak frequencies and peak intensities and extraordinary enhancements of several peaks. The fluctuating TERS signals originate primarily from the molecules in the first layer of the 5 nm thick adenine nanocrystalline cluster. The possible origin of the temporal changes is attributed to the changes of molecular orientation under the metal-coated tip, which is responsible for changing the adsorption angle and the angle of local incident polarization for the molecules adsorbed to the tip. This result suggests the importance of sample−tip interaction at molecular level in the interpretation of TERS spectra and indicates the possibility of the single molecule sensitivity of TERS spectroscopy of DNA base molecules.