Tip-enhanced near-field Raman analysis of tip-pressurized adenine molecule
Tip-enhanced near-field Raman analysis of tip-pressurized adenine molecule
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DOI：
10.1103/physrevb.69.155418
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发表时间：
2004-04-01
影响因子：
3.7
通讯作者：
Kawata, S
中科院分区：
文献类型：
--
作者：
Watanabe, H;Ishida, Y;Kawata, S
本文报道了用原子力显微镜的镀银无孔探针对单碱基腺嘌呤分子的近场拉曼光谱的研究。针尖增强近场拉曼光谱显示了八个拉曼谱带，根据密度泛函理论（DFT）计算，这些谱带被归属于腺嘌呤分子的简正模。观察到几个频带的振动频率已明确转移到相应的频带的值，观察到使用常规的表面增强拉曼散射光谱的腺嘌呤分子吸附在胶体银颗粒。含银原子的腺嘌呤复合物的DFT振动计算表明，探针针尖上的银原子使腺嘌呤分子变形，从而使拉曼光谱发生了位移。
We report on near-field Raman spectra of a single nanocrystal of DNA-base adenine molecules using a silver-layer-coated apertureless probe tip of an atomic force microscope. The tip-enhanced near-field Raman spectrum shows eight Raman bands that are assigned to the normal modes of adenine molecules based on the density-functional theory (DFT) calculations. The vibrational frequencies of several bands are observed to have unambiguously shifted to the values of the corresponding bands, observed using the conventional surface-enhanced Raman-scattering spectrum of adenine molecules adsorbed on colloidal silver particles. The DFT vibrational calculations of adenine complexes involving a silver atom suggest that the Raman band shifts occur due to the deformation of adenine molecules by the silver atoms coated in the probe tip.