State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
Talanta. 2024 Oct 1;278:126550. doi: 10.1016/j.talanta.2024.126550. Epub 2024 Jul 11.
In this study, a low field nuclear magnetic resonance (LF-NMR) homogeneous sensor was constructed for detection of Escherichia coli (E. coli) based on the copper metabolism of E. coli triggered click reaction. When live E. coli was present, a large amount of Cu ions were transformed into Cu via copper metabolism, which then catalyzed a Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between two materials, azide group modified gadolinium oxide nanorods (GdO-Az) and PA-GO@FeO i.e., graphene oxide (GO) loaded with large amounts of alkynyl (PA) groups and FeO nanoparticles simultaneously. After magnetic separation, unbound GdO-Az was dissolved by added hydrochloric acid (HCl) to generate homogeneous Gd solution, enabling homogeneous detection of E. coli. Triple signal amplification was achieved through the CuAAC reaction induced by E. coli copper metabolism, functional nanomaterials, and HCl assisted homogeneous detection. Under the optimal experimental conditions, the linear range and limit of detection (LOD) for E. coli were 10-1.0 × 10 CFU/mL and 3.5 CFU/mL, respectively, and the relative standard deviations (RSDs) were all less than 2.8 %. In addition, the sensor has satisfactory selectivity, stability and practical sample application capability, providing a new approach for the LF-NMR detection of food-borne pathogenic bacteria.
在这项研究中，基于大肠杆菌（E. coli）的铜代谢触发点击反应，构建了一种用于检测大肠杆菌的低场核磁共振（LF-NMR）均相传感器。当活的大肠杆菌存在时，大量的 Cu 离子通过铜代谢转化为 Cu，然后在两种材料之间催化铜催化的叠氮化物-炔烃环加成（CuAAC）反应，这两种材料分别是叠氮基修饰的氧化钆纳米棒（GdO-Az）和 PA-GO@FeO，即同时负载大量炔基（PA）基团和 FeO 纳米颗粒的氧化石墨烯（GO）。通过加入盐酸（HCl）使未结合的 GdO-Az 溶解，产生均相 Gd 溶液，从而实现对大肠杆菌的均相检测。通过大肠杆菌铜代谢诱导的 CuAAC 反应、功能纳米材料和 HCl 辅助的均相检测，实现了三重信号放大。在最佳实验条件下，大肠杆菌的线性范围和检测限（LOD）分别为 10-1.0×10 CFU/mL 和 3.5 CFU/mL，相对标准偏差（RSDs）均小于 2.8%。此外，该传感器具有令人满意的选择性、稳定性和实际样品应用能力，为食源性致病菌的 LF-NMR 检测提供了一种新方法。
