Institute of Biomedical Precision Testing and Instrumentation, College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, Shanxi, China.
Analysis & Testing Center, Jilin Institute of Chemical Technology, Jilin, 132000, Jilin, China.
Mikrochim Acta. 2024 Jul 8;191(8):454. doi: 10.1007/s00604-024-06497-9.
An intelligent colorimetric sensing platform integrated with in situ immunomagnetic separation function was developed for ultrasensitive detection of Escherichia coli O157: H7 (E. coli O157: H7) in food. Captured antibody modified magnetic nanoparticles (cMNPs) and detection antibody/horseradish peroxidase (HRP) co-functionalized AuNPs (dHAuNPs) were firstly synthesized for targeted enrichment and colorimetric assay of E. coli O157: H7, in which remarkable signal amplification was realized by loading large amounts of HRP on the surface of AuNPs. Coupling with the optical collimation attachments and embedded magnetic separation module, a highly integrated optical device was constructed, by which in situ magnetic separation and high-quality imaging of 96-well microplates containing E. coli O157: H7 was achieved with a smartphone. The concentration of E. coli O157: H7 could be achieved in one-step by performing digital image colorimetric analysis of the obtained image with a custom-designed app. This biosensor possesses high sensitivity (1.63 CFU/mL), short detecting time (3 h), and good anti-interference performance even in real-sample testing. Overall, the developed method is expected to be a novel field detection platform for foodborne pathogens in water and food as well as for the diagnosis of infections due to its portability, ease of operation, and high feasibility.
一种集成原位免疫磁分离功能的智能比色传感平台被开发用于食品中大肠杆菌 O157:H7（E. coli O157:H7）的超灵敏检测。捕获抗体修饰的磁性纳米颗粒（cMNPs）和检测抗体/辣根过氧化物酶（HRP）共功能化的 AuNPs（dHAuNPs）首先被合成用于 E. coli O157:H7 的靶向富集和比色分析，其中通过在 AuNPs 表面加载大量的 HRP 实现了显著的信号放大。通过与光学准直附件和嵌入式磁分离模块结合，构建了一个高度集成的光学器件，通过该器件可以使用智能手机对含有 E. coli O157:H7 的 96 孔微孔板进行原位磁分离和高质量成像。通过使用自定义设计的应用程序对获得的图像进行数字图像比色分析，可以一步实现大肠杆菌 O157:H7 的浓度检测。该生物传感器具有高灵敏度（1.63 CFU/mL）、短检测时间（3 小时）和良好的抗干扰性能，即使在实际样品检测中也是如此。总的来说，由于其便携性、易于操作和高可行性，该方法有望成为一种用于水和食品中食源性病原体以及感染诊断的新型现场检测平台。
