School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Institute of Microbiology and Epidemiology, Beijing, PR China.
College of Intelligence Science, National University of Defense Technology, Changsha 410073, PR China.
J Hazard Mater. 2022 Sep 5;437:129347. doi: 10.1016/j.jhazmat.2022.129347. Epub 2022 Jun 11.
Rapid and sensitive detection of multiple foodborne bacteria without DNA amplification is still challenging. Here, we proposed an immunochromatographic assay (ICA) with multiplex analysis ability and high sensitivity for direct detection of bacteria in real food samples, based on an improved surface-enhanced Raman scattering (SERS) sensing strategy. Multifunctional Au shell-coated graphene oxide nanosheets (GO@Au) were fabricated and for the first time introduced into the ICA system as a two-dimensional film-like SERS label, which possessed huge surface area, excellent stability, and superior SERS activity. Different from the conventional spherical nanotags, the antibody-conjugated GO@Au nanosheet effectively and rapidly adhered to bacterial cells, improved the dispersibility of bacteria-nanolabel complexes on the ICA strips, and provided numerous stable hotspots for SERS signal enhancement. The combination of GO@Au labels and the ICA system achieved the multiplex and ultrasensitive determination of three major foodborne pathogens, namely, Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium, in a single test, with low detection limits (8, 10, and 10 cells/mL) and short detection time (20 min). The proposed biosensor demonstrated high stability and good accuracy in various food samples and is thus a promising tool for the rapid identification of bacteria.
快速、灵敏地检测多种食源性细菌而无需 DNA 扩增仍然具有挑战性。在这里，我们提出了一种基于改进的表面增强拉曼散射（SERS）传感策略的具有多重分析能力和高灵敏度的免疫层析分析（ICA）方法，用于直接检测实际食品样品中的细菌。制备了多功能 Au 壳包覆的氧化石墨烯纳米片（GO@Au），并首次将其作为二维薄膜状 SERS 标签引入 ICA 系统，其具有巨大的表面积、优异的稳定性和卓越的 SERS 活性。与传统的球形纳米标签不同，抗体偶联的 GO@Au 纳米片有效地、快速地附着在细菌细胞上，提高了 ICA 条上细菌-纳米标签复合物的分散性，并为 SERS 信号增强提供了大量稳定的热点。GO@Au 标签与 ICA 系统的结合实现了三种主要食源性致病菌（金黄色葡萄球菌、大肠杆菌 O157:H7 和鼠伤寒沙门氏菌）的多重和超灵敏检测，检测限低（8、10 和 10 个细胞/mL），检测时间短（20 分钟）。该生物传感器在各种食品样品中表现出高稳定性和良好的准确性，因此是一种快速鉴定细菌的有前途的工具。
