Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, and The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China.
Donostia International Physics Center (DIPC) and Material Physics Center (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain.
Nat Commun. 2017 Mar 28;8:14891. doi: 10.1038/ncomms14891.
Surface-enhanced Raman scattering (SERS) spectroscopy has attracted tremendous interests as a highly sensitive label-free tool. The local field produced by the excitation of localized surface plasmon resonances (LSPRs) dominates the overall enhancement of SERS. Such an electromagnetic enhancement is unfortunately accompanied by a strong modification in the relative intensity of the original Raman spectra, which highly distorts spectral features providing chemical information. Here we propose a robust method to retrieve the fingerprint of intrinsic chemical information from the SERS spectra. The method is established based on the finding that the SERS background originates from the LSPR-modulated photoluminescence, which contains the local field information shared also by SERS. We validate this concept of retrieval of intrinsic fingerprint information in well controlled single metallic nanoantennas of varying aspect ratios. We further demonstrate its unambiguity and generality in more complicated systems of tip-enhanced Raman spectroscopy (TERS) and SERS of silver nanoaggregates.
表面增强拉曼散射（SERS）光谱学作为一种高灵敏度的无标记工具引起了极大的关注。局域表面等离激元共振（LSPR）激发产生的局域场主导着 SERS 的整体增强。这种电磁增强伴随着原始拉曼光谱的相对强度的强烈变化，这强烈地扭曲了提供化学信息的光谱特征。在这里，我们提出了一种从 SERS 光谱中恢复固有化学信息的指纹的稳健方法。该方法基于以下发现：SERS 背景源自受 LSPR 调制的光致发光，其包含也由 SERS 共享的局域场信息。我们在具有不同纵横比的单金属纳米天线的良好控制的实验中验证了这种内在指纹信息恢复的概念。我们还在更复杂的尖端增强拉曼光谱学（TERS）和银纳米聚集体的 SERS 系统中证明了其明确性和通用性。
