School of Pharmacy, Changzhou University, Changzhou, 213164, China.
School of Pharmacy, Changzhou University, Changzhou, 213164, China.
Talanta. 2024 Dec 1;280:126783. doi: 10.1016/j.talanta.2024.126783. Epub 2024 Aug 27.
Escherichia coli (E. coli) is a prevalent pathogen that is frequently associated with the foodborne illness. It causes various infections and poses a significant threat to human health. A rapid and sensitive assay for detecting E. coli is essential for timely diagnosis. Herein, a simple and sensitive colorimetric analysis method for detecting E. coli was developed based on the formation of Au@Ag core-shell nanoparticles facilitated by p-benzoquinone (BQ). E. coli reduced p-benzoquinone to generate hydroquinone (HQ), which could reduce the added Tollens' reagent to silver elemental and grow on the surface of gold nanoparticles (AuNPs). As the E. coli concentration increased, the silver layer thickess on the AuNPs surface growed, resulting in a stronger silver absorption peak observed at 390 nm. The color of the solution changed from red to orange, which could be used to detect E. coli by the naked eye. As a result, E. coli was detected with a linear range from 1.0 × 10 to 1.0 × 10 CFU/mL based on the absorbance intensity. In addition, this method accurately detected E. coli in real milk sample, demonstrating promising applications in foodborne pathogen detection. With satisfactory accuracy, the proposed colorimetric method holds excellent prospects in detecting pathogens in actual food samples.
大肠杆菌（E. coli）是一种常见的病原体，常与食源性疾病有关。它会引起各种感染，对人类健康构成重大威胁。因此，快速、灵敏地检测大肠杆菌对于及时诊断至关重要。在此，我们基于对苯醌（BQ）介导的 Au@Ag 核壳纳米粒子的形成，开发了一种简单、灵敏的比色分析方法来检测大肠杆菌。大肠杆菌将对苯醌还原为对苯二酚（HQ），HQ 可以将添加的 Tollens 试剂还原为银元素，并在金纳米粒子（AuNPs）表面生长。随着大肠杆菌浓度的增加，AuNPs 表面的银层厚度增加，导致在 390nm 处观察到更强的银吸收峰。溶液的颜色从红色变为橙色，可通过肉眼检测大肠杆菌。因此，基于吸光度强度，大肠杆菌的检测线性范围为 1.0×10 至 1.0×10 CFU/mL。此外，该方法还能准确检测实际牛奶样品中的大肠杆菌，有望应用于食源性病原体检测。该比色法具有令人满意的准确性，在实际食品样品中检测病原体方面具有广阔的应用前景。
