Understanding tip-enhanced Raman spectra of biological molecules: a combined Raman, SERS and TERS study
Understanding tip-enhanced Raman spectra of biological molecules: a combined Raman, SERS and TERS study
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DOI：
10.1002/jrs.4099
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发表时间：
2012-12-01
影响因子：
2.5
通讯作者：
Zenobi, Renato
中科院分区：
文献类型：
--
作者：
Blum, Carolin;Schmid, Thomas;Zenobi, Renato
尽管传统拉曼、表面增强拉曼（SERS）和尖端增强拉曼光谱（TERS）早已为人所知，但从未对这三种方法进行直接、彻底的比较。在本文中，对传统拉曼、SERS（在金和银基底上）和 TERS（在银尖端和金基底的间隙模式下）获得的光谱进行了比较，以了解它们的差异和相似之处。由于 TERS 对生物样品的研究最近已成为热门话题，因此本工作重点关注生物相关物质。以牛血清白蛋白的 TER 谱作为蛋白质的示例，研究了二肽 PhePhe 和 TyrTyr 以及三肽 TyrTyrTyr。主要调查结果如下。 (1) 我们证明了广泛使用的假设，即在比较 SER、TER 和传统拉曼光谱时（除了 SERS 或 TERS 中与金属表面的结合），谱带不会发生偏移，这一假设是有效的。然而，这三种方法之间的条带强度比可能存在显着差异。 （2）可以分配标记带，这应该允许人们在未来的研究中识别和定位复杂生物环境中的蛋白质。根据我们的结果，提出了解释 TER 光谱的一般准则。版权所有 (c) 2012 John Wiley & Sons, Ltd.
Although conventional Raman, surface-enhanced Raman (SERS) and tip-enhanced Raman spectroscopy (TERS) have been known for a long time, a direct, thorough comparison of these three methods has never been carried out. In this paper, spectra that were obtained by conventional Raman, SERS (on gold and silver substrates) and TERS (in gap mode with silver tips and gold substrates) are compared to learn from their differences and similarities. Because the investigation of biological samples by TERS has recently become a hot topic, this work focuses on biologically relevant substances. Starting from the TER spectra of bovine serum albumin as an example for a protein, the dipeptides PhePhe and TyrTyr and the tripeptide TyrTyrTyr were investigated. The major findings were as follows. (1) We show that the widely used assumption that spectral bands do not shift when comparing SER, TER and conventional Raman spectra (except due to binding to the metal surface in SERS or TERS) is valid. However, band intensity ratios can differ significantly between these three methods. (2) Marker bands can be assigned, which should allow one to identify and localize proteins in complex biological environments in future investigations. From our results, general guidelines for the interpretation of TER spectra are proposed. Copyright (c) 2012 John Wiley & Sons, Ltd.