表面增强拉曼光谱技术在食品痕量化学危害检测中的应用

表面增强拉曼光谱(surface-enhanced Raman spectroscopy, SERS)技术是基于被测分子吸附在某些经特殊处理、具有纳米结构的金属表面具有极强拉曼散射增强效应的分子振动光谱技术。因SERS技术具有前处理简单、操作简便、检测时间短、灵敏度高等优点，在食品安全检测领域具有良好的应用前景。食品中化学危害残留超标是主要的食品安全问题之一，已引起全球的关注，SERS技术对食品中痕量化学危害的分子识别及定量分析检测的相关研究报道数量近年来呈上升趋势。本综述概括了应用SERS对食品中常被检出的非法添加物、农药残留、抗生素及其他药物残留检测中的应用和研究进展，涉及的拉曼散射增强基底体系多种多样，如金或银等纳米溶胶体系、金纳米固体表面基底、双金属或磁性内核等复合基底。研究对象一般以化学危害物的标准溶液为起点，扩展到常被检出该化学危害物的相应食品中，如乳制品、鱼、果蔬等。由于表面增强拉曼散射强度受多种因素的影响，SERS谱图的重现性还是一个亟需解决的难题，而食品复杂体系中非目标组分对被分析物拉曼散射信号的干扰导致SERS技术还不能成为一种有效的常规快速分析方法，但SERS为食品及其他复杂体系中痕量化学物的检测提供了一个新的极具潜力的工具。

Application of Surface-Enhanced Raman Spectroscopy to the Determination of Trace Chemical Hazards in Food Products

In the present review, we summarized the research progress in applying SERS for the determination of illegal food additives, residual pesticides, banned or restricted antibiotics and other drugs. The nanosubstrates used in these studies included, but were not limited to, gold and silver nanosphere colloids, solid surface gold coated nanosubstrates, bimetallic nanosubstrates and spherical magnetic-core gold-shell nanoparticles, and etc. Standard solutions of a targeted chemical were normally tested first before analysis of relevant food in which the targeted chemical was commonly detected, and the tested food products included dairy products, condiments (such as chili powder and spices), fish, fruits and vegetables. The intensity of surface-enhanced Raman scattering signal is affected by various factors, which makes it difficult to obtain reproducible spectra. In addition, interferences of non-targeted food components on the target molecules during SERS analyses further makes it difficult to apply SERS as a routine analytic technique, despite its high specificity and sensitivity. Nevertheless, SERS is a new tool with great potential for analysis of trace amounts of chemical hazards in various food products and other complex systems.