基于SERS的三种食源性致病菌的快速检测

为了探究表面增强拉曼光谱(SERS)法在大肠杆菌(ATCC 25922)、肠炎沙门氏菌(CICC 21540)和单核增生李斯特菌(CICC 10982)快速检测中的可行性,本研究利用两步生长法制备银包金纳米颗粒(Au@Ag NPs)作为增强基底,研究Au@Ag NPs分别与3种致病菌偶联后的拉曼增强效果和稳定性,并对3种致病菌的特征拉曼光谱结合主成分分析(PCA)和层次聚类分析(HCA)进行对比分析。结果表明,合成的Au@Ag NPs颗粒大小均匀,拉曼增强效果明显,可与3种致病菌有效结合,且均有稳定的拉曼响应度;基于大肠杆菌、肠炎沙门氏菌和单核增生李斯特菌的特征拉曼光谱的PCA和HCA分析得出,3种致病菌的拉曼特征光谱之间差异明显,能有效区分。本研究结果为利用Au@Ag NPs作为增强基底的SERS方法快速检测大肠杆菌、肠炎沙门氏菌和单核增生李斯特菌提供了参考基础。

Rapid Detection of Three Foodborne Pathogens Based on SERS

In order to explore the feasibility of Surface-enhanced Raman Spectroscopy (SERS) method for rapid detection of Escherichia coli (ATCC 25922), Salmonella enteritidis (CICC 21540) and Listeria monocytogenes (CICC 10982), a two-step growth method was used to prepare silver-coated gold nanoparticles (Au@Ag NPs) as an enhanced substrate in this study. The Raman enhancement effect and stability of Au@Ag NPs coupled with three pathogenic bacteria were studied respectively. The characteristic Raman spectroscopy of the pathogenic bacteria was comparatively analyzed with the combination with principal component analysis (PCA) and hierarchical clustering analysis (HCA). The results showed that the synthesized Au@Ag NPs had uniform particle size, obvious Raman enhancement effect, which could effectively combine with the 3 kinds of pathogenic bacteria to generate stable Raman response; PCA and HCA analysis based on the characteristic Raman spectra of Escherichia coli, Salmonella enteritidis and Listeria monocytogenes showed that the Raman characteristic spectra of the three pathogenic bacteria were obviously different and could be effectively distinguished. The results of this study provide a reference basis for the rapid detection of E. coli, S. enteritidis and L. monocytogenes by using SERS method with Au@Ag NPs as the enhanced substrate.