Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia; Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Al Azhar University, Assiut Branch 71526, Egypt.
Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia.
Food Chem. 2024 Jun 15;443:138564. doi: 10.1016/j.foodchem.2024.138564. Epub 2024 Jan 26.
Escherichia coli O157:H7 (E. coli O157:H7) emerges as a significantly worrisome pathogen associated with foodborne illnesses, emphasizing the imperative for creating precise detection tools. In this investigation, we developed a sensitive colorimetric biosensor for detecting E. coli O157:H7. It was constructed using a nanozyme comprised of Au@FeO NPs, which was fabricated and subsequently modified with an aptamer (Apt). The nanozyme harnesses its inherent peroxidase-like activity to facilitate the transformation of reduced TMB into its oxidized form in the presence of HO, resulting in a noticeable shift to a blue color. However, the presence of E. coli O157:H7 effectively diminished the absorbance of oxidized TMB. Consequently, the normalized absorbance at 652 nm demonstrates a linear decrease corresponding to concentrations of E. coli O157:H7 within the range of 10 to 10 CFU mL with a low limit of detection (LOD, S/N = 3) of 3 CFU mL.
产志贺毒素大肠杆菌 O157:H7（Escherichia coli O157:H7）是一种与食源性疾病相关的重要病原体，这强调了开发精确检测工具的必要性。在本研究中，我们开发了一种用于检测产志贺毒素大肠杆菌 O157:H7 的灵敏比色生物传感器。它是使用由 Au@FeO NPs 组成的纳米酶构建的，该纳米酶经过制备并随后用适配体（Apt）进行修饰。纳米酶利用其内在的过氧化物酶样活性，在 HO 的存在下将还原型 TMB 转化为其氧化形式，从而导致颜色明显变为蓝色。然而，产志贺毒素大肠杆菌 O157:H7 的存在有效地降低了氧化型 TMB 的吸光度。因此，归一化吸光度在 652nm 处显示出与产志贺毒素大肠杆菌 O157:H7 浓度在 10 到 10 CFU mL 范围内呈线性下降的关系，检测限（LOD，S/N=3）低至 3 CFU mL。
