Abstract：
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.
摘要：
开发了集成了原位免疫磁珠分离功能的智能比色传感平台，用于超灵敏检测大肠杆菌O157：H7（E。食物中的大肠杆菌O157：H7）。首先合成了捕获的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），用于大肠杆菌O157：H7的靶向富集和比色测定，其中通过在AuNPs表面加载大量的HRP实现了显着的信号放大。与光学准直附件和嵌入式磁分离模块耦合，构建了高度集成的光学设备，通过智能手机实现了含有大肠杆菌O157：H7的96孔微孔板的原位磁分离和高质量成像。通过使用定制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。该生物传感器具有较高的灵敏度(1.63CFU/mL),检测时间短（3小时），和良好的抗干扰性能，即使在真实的样品测试。总的来说,所开发的方法由于其便携性，有望成为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，操作方便,可行性高。
