Anhui Agricultural University, Hefei, 230036, PR China; Beijing Institute of Radiation Medicine, Beijing, 100850, PR China; Anhui Province Engineering Laboratory for Animal Food Quality and Bio-safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, PR China.
Beijing Institute of Radiation Medicine, Beijing, 100850, PR China.
Anal Chim Acta. 2021 May 22;1160:338421. doi: 10.1016/j.aca.2021.338421. Epub 2021 Mar 18.
Rapid, reliable and sensitive detection methods for pathogenic bacteria are strongly demanded. Herein, we proposed a magnetically assisted surface enhanced Raman scattering (SERS)-label immunoassay for the sensitive detection of bacteria by using a universal approach based on free antibody labelling and staphylococcus proteins A (PA)-SERS tags orientation recognition. The SERS biosensor consists of two functional nanomaterials: aptamer-conjugated FeO@Au magnetic nanoparticles (MNPs) as magnetic SERS platform for pathogen enrichment and PA modified-SERS tags (Au@DTNB@PA) as a universal probe for target bacteria quantitative detection. After target bacteria enriched, free antibody was used to specific marking target bacteria and provided numerous Fc fragment, which can guide the PA-SERS tags orientation-dependent binding. With this strategy, FeO@Au/bacteria/SERS tags sandwich immunocomplexes for most bacteria (expect several species of Staphylococcus) were easy constructed. The limits of detection (LODs) of the proposed assay were found to be 10, 10, and 25 cells/mL for three common pathogens Escherichia coli (E. coli), Listeria monocytogenes (L. mono), and Salmonella typhimurium (S. typhi), respectively, in real food samples. The universal method also exhibits the advantages of rapid, robust, and easy to operate, suggesting its great potential for food safety monitoring and infectious diseases diagnosis.
快速、可靠和敏感的致病菌检测方法受到强烈需求。在此，我们提出了一种基于自由抗体标记和葡萄球菌蛋白 A（PA）-SERS 标签定向识别的通用方法，通过磁辅助表面增强拉曼散射（SERS）-标记免疫分析来灵敏检测细菌。该 SERS 生物传感器由两种功能纳米材料组成：适配体偶联的 FeO@Au 磁性纳米颗粒（MNPs）作为病原体富集的磁性 SERS 平台和 PA 修饰的 SERS 标签（Au@DTNB@PA）作为通用探针用于目标细菌的定量检测。在富集目标细菌后，使用游离抗体特异性标记目标细菌并提供大量 Fc 片段，其可以引导 PA-SERS 标签的定向结合。采用这种策略，对于大多数细菌（除了几种葡萄球菌），FeO@Au/细菌/SERS 标签三明治免疫复合物易于构建。在实际食品样本中，该方法对三种常见病原体大肠杆菌（E. coli）、单核细胞增生李斯特菌（L. mono）和鼠伤寒沙门氏菌（S. typhimurium）的检测限（LOD）分别为 10、10 和 25 个细胞/mL。该通用方法还具有快速、稳健和易于操作的优点，表明其在食品安全监测和传染病诊断方面具有巨大潜力。
