拉曼光谱中荧光抑制技术的研究新进展综述

Latest Methods of Fluorescence Suppression in Raman Spectroscopy

拉曼光谱技术反映了物质的结构特征,可用于分析有机或者无机样品的化学组分。但由于某些被测物的荧光背景远远强于拉曼信号,这些物质的拉曼光谱测量有时十分困难,这限制了拉曼光谱的广泛应用。因此有必要在拉曼检测中对荧光采取抑制措施以准确获取高信噪比的拉曼光谱指纹信息。近些年来,很多的相关研究探讨及发展了多种荧光抑制的新方法。在目前的科研活动中,常用的技术有表面增强拉曼光谱技术、傅里叶变换拉曼光谱技术、共焦显微拉曼光谱技术和高温拉曼光谱技术等。这些技术解决了拉曼光谱早期存在的一些问题,如荧光干扰、灵敏度低等,极大地扩展了拉曼光谱技术在各个领域的应用。而这些新方法可大致归类为物理/化学方法,基于光学性质不同衍生的方法,计算处理方法和其他方法。文章概括性的介绍了上述方法的理论、实现方式,并分析比较了各自的特点。

Raman spectroscopy provides the fingerprint of the molecules,and is an important and powerful technique for analyzing the chemical composition of biological or non-biological samples.However,in many cases,the existence of the concurrent fluorescence background seriously interferes with Raman measurements.The excitation laser induced fluorescence intensity can be sometimes several orders of magnitudes higher than that of the Raman scattering signals.Such fluorescence backgrounds must be suppressed during the measurement in that Raman spectral fingerprints have to be measured accurately with high signal-to-noise ratio.A variety of techniques have been explored in researches and practical applications for this purpose.In present scientific researches,common methods include Surface Enhanced Raman Spectroscopy,Fourier Transform Raman Spectroscopy,microRaman Techniques and High Temperature Raman Spectroscopy Techniques.All these solve the problems such as fluorescence interference and insensitivity,which greatly expands the application range of Raman spectroscopy.These techniques may be generally grouped into the categories of physical/chemical,optical properties,chemometric methods and other unconventional methods.This review briefly describes the fundamental principle and implementation of each group of the methods,and makes comparison between those major categories of techniques.