表面增强拉曼光谱在食源性致病微生物检测中的应用研究

食源性致病微生物导致的食源性疾病已成为全球化的公共卫生问题。快速、有效地检测食源性致病微生物是实现食源性疾病预防与控制的关键环节,也是保障食品安全的技术关键。表面增强拉曼光谱(SERS)具有简单、快速、灵敏度高等优点,在食品安全、生物医学、环境监控等领域展现出良好的应用前景。介绍了近年来SERS在食源性致病微生物检测中的应用研究进展。对SERS技术概况、SERS增强理论及SERS增强基底进行了简要介绍,重点回顾了SERS在食源性致病微生物检测中的应用和发展现状。在食品安全分析方面,利用SERS与模式识别方法相结合对食品中常见食源性致病微生物能实现快速、有效鉴别,部分研究已应用于不同食品样品的分析,体现了SERS作为"指纹图谱"的分析优势;在医学诊断方面,SERS可对病理样品(如血液、尿液等)中食源性致病微生物进行快速检测,缩短了样本分析时间,使食源性疾病的快速诊断成为可能;随着微流控技术的发展,微流控平台结合SERS技术被称为"芯片实验室"应用于食源性致病微生物的检测,可提高分析的可控性,稳定性,特异性和灵敏度。通过对比分析,发现不同研究可采用不同分离方法、不同基底、不同目标捕获方式等实现了食源性致病微生物的检测,展示了不同方法间的差异性。已有研究表明了SERS在食源性致病微生物检测中应用可克服传统方法耗时等缺点,实现灵敏快速分析,为食品安全实时监控,食源性疾病即时诊断提供了有效的分析工具。同时,指出了SERS技术应用于食源性致病微生物分析依然面临很大挑战,(1)大多数研究并没有聚焦于实际样品,而标准培养液和实际样品的SERS检测存在较大差异,实际样品组分会对SERS响应产生干扰;(2)不同方法结果有较大差异,主要是由于纳米增强基底差异,吸附方式原理的差异,稳定性的差异等,因此需要更多深入研究进一步优化条件;(3)期望建立标准化的SERS方法替代传统技术,充分展示SERS作为新兴分析工具快速、灵敏、简捷的优势应用于食品安全,医学诊断等领域。将来,随着研究的深入及相关学科的发展,SERS作为极具潜力的快速分析工具,将在食品安全,生物医学等领域具有更广阔的应用前景。

Application of Surface-Enhanced Raman Spectroscopy for Foodborne Pathogens Detection

Foodborne diseases caused by food-borne pathogen have become a global public health problem. Rapid and accurate detection of food-borne pathogenic microorganisms has become a key to the prevention and control of food-borne diseases and is also the key technology to ensuring food safety. Surface-enhanced Raman spectroscopy (SERS), as a powerful and attractive analytical tool, has the advantages of simplicity, rapidness and high sensitivity. This review summarizes the recent trends and developments of SERS in the detection of food-borne pathogenic microorganisms. A brief tutorial on SERS, the SERS enhancement theory and SERS enhancement substrate are given first of all. Then we summarize the recent trends and developments of SERS applied to the detection of foodborne pathogen in food and medical diagnosis. In addition, microfluidic SERS platforms for foodborne pathogen are discussed as well. In the field of food safety analysis, SERS combined with pattern recognition methods can rapidly and effectively identify common food-borne pathogenic microorganisms. Some studies have reported to apply SERS to detect food-borne pathogenic microorganisms in different food samples, which demonstrates the advantage of SERS as “fingerprint”. In medical diagnosis, SERS can rapidly detect food-borne pathogenic microorganisms in pathological samples (such as blood and urine). The application of SERS makes the rapid diagnosis of food-borne diseases possible due to the shortening of the sample analysis time. With the development of microfluidic technology, microfluidic platform combined with SERS technology is called “chip lab”, which can improve the controllability, stability, specificity and sensitivity for detection of food-borne pathogenic microorganisms. The review summarized and compared these different studies of SERS methods, which could be used to detect food-borne pathogenic microorganisms based on different isolation methods, different substrates or different target capture methods. These researches have demonstrated that the application of SERS in foodborne pathogenic microorganisms could overcome the shortcomings of traditional methods, and provide an effective, rapid and sensitive analytical tool for real-time monitoring of food safety and diagnosis of foodborne diseases. At the same time, there are still great challenges for the application of SERS technology in foodborne pathogenic microorganism analysis. (1) Most researches do not focus on the actual samples. However, there is really difference between the standard culture medium and the actual samples for SERS analysis. (2) There are differences between the results of different methods, mainly due to the difference of SERS substrate, the difference of the target adsorption modes, the difference of stability and so on. So further studies are needed for optimization conditions. (3) It is expected to establish standardized SERS methods to replace the traditional techniques, which could fully show the advantages of SERS including rapidness, sensitivity and simplicity. An outlook of the work done and a perspective on the future directions of SERS as a reliable and rapid analytical tool are given for a broader application prospect in food safety, biomedicine and other fields in the future.