Institute of Environment and Safety, Wuhan Academy of Agricultural Science, Wuhan 430207, P. R. China.
Anal Methods. 2020 Oct 22;12(40):4885-4891. doi: 10.1039/d0ay01541e.
A reliable and sensitive sensing of multiple foodborne pathogens is critical for timely diagnosis and human health. To meet this need, herein, we designed a sandwich immunoassay platform, using functionalized SERS probes and magnetic beads, for the interference-free simultaneous detection of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in food samples by surface-enhanced Raman scattering (SERS) technology. The signal of two SERS probes coded by triple bonds (C[triple bond, length as m-dash]C and C[triple bond, length as m-dash]N) located at 2105 and 2227 cm-1, respectively, could perfectly avoid the spectral overlap with coexisting materials in the Raman fingerprint region, which ensured the accuracy of the immunoassay platform. The application of functional magnetic beads, integrating enrichment and separation, greatly improved the sensitivity of the detection system. Under magnetic force, due to the mature interaction between the antigen and antibody, the sandwich immunoassay platform could be fabricated. Its limit of detection (LOD) for the simultaneous detection of E. coli and S. aureus was as low as 10 and 25 cfu mL-1, respectively, and the sandwich immunoassay platform was successfully applied for the detection of E. coli and S. aureus in bottled water and milk. As a sensitive and highly selective analytical technique for the simultaneous multiple detection of pathogens, this SERS-based method has great potential to be applied in the field of food safety.
一种可靠且灵敏的多食物病原体感测对于及时诊断和人类健康至关重要。为满足这一需求，本文设计了一种基于表面增强拉曼散射（SERS）技术的三明治免疫分析平台，使用功能化的 SERS 探针和磁性珠，实现对食品样品中大肠杆菌（E. coli）和金黄色葡萄球菌（S. aureus）的无干扰同时检测。两个 SERS 探针的信号由三键（C[三键，长度为破折号]C 和 C[三键，长度为破折号]N）编码，分别位于 2105 和 2227 cm-1，其光谱可完美避免与拉曼指纹区域共存物质的光谱重叠，从而确保了免疫分析平台的准确性。功能化磁性珠的应用，集富集和分离于一体，极大地提高了检测系统的灵敏度。在磁力作用下，由于抗原和抗体之间成熟的相互作用，可构建三明治免疫分析平台。其同时检测大肠杆菌和金黄色葡萄球菌的检测限（LOD）分别低至 10 和 25 cfu mL-1，并且该三明治免疫分析平台成功应用于瓶装水和牛奶中大肠杆菌和金黄色葡萄球菌的检测。作为一种用于同时多重检测病原体的灵敏且高选择性分析技术，这种基于 SERS 的方法在食品安全领域具有很大的应用潜力。
