School of Public Health, Jilin University, Changchun, 130021, China.
School of Public Health, Jilin University, Changchun, 130021, China.
Talanta. 2021 Sep 1;232:122448. doi: 10.1016/j.talanta.2021.122448. Epub 2021 May 1.
Staphylococcus aureus (S. aureus) is one of the most threatened food-borne pathogens. Thus, it is necessary to establish fast, portable and reliable tools to realize the identification of S. aureus. Herein, the authors describe an effective colorimetric-based biosensor for the detection of S. aureus in multiple types of samples. Initially, a nanozyme composed of gold and iron oxide nanoparticles was synthesized and further modified with S. aureus-specific aptamer via Au-S bond. By utilizing the intrinsic peroxidase-like activity of the above magnetic conjugates, 3,3',5,5'-tetramethylbenzidine (TMB) can be transferred to oxTMB by oxidation of hydrogen peroxide (HO), resulting in a visible blue color. However, the introduction of S. aureus can turn off the UV-vis absorbance signals of TMB-HO system, due to the identification property of the nanozyme probe. Consequently, the optical density of the mixed solution measured at 652 nm decreased linearly as the concentration of S. aureus increased from 10 to 10 CFU mL, with the visible limit of detection as low as 10 CFU mL. The as-prepared sensor can detect S. aureus in spiked water, milk and urine samples quantitatively during 12 min without any pre-enrichment, separation or washing steps. In our perception, the one-step colorimetric assay show promise in practical on-site detection of S. aureus.
金黄色葡萄球菌（S. aureus）是最具威胁的食源性致病菌之一。因此，有必要建立快速、便携和可靠的工具来实现金黄色葡萄球菌的鉴定。在此，作者描述了一种用于检测多种类型样品中金黄色葡萄球菌的有效比色生物传感器。首先，合成了一种由金和氧化铁纳米粒子组成的纳米酶，并通过 Au-S 键进一步修饰了金黄色葡萄球菌特异性适配体。利用上述磁性偶联物固有的过氧化物酶样活性，通过过氧化氢（HO）的氧化，3,3',5,5'-四甲基联苯胺（TMB）可以转化为 oxTMB，从而产生可见的蓝色。然而，由于纳米酶探针的识别特性，金黄色葡萄球菌的引入可以关闭 TMB-HO 体系的紫外-可见吸收信号。因此，当金黄色葡萄球菌的浓度从 10 到 10 CFU mL 增加时，混合溶液在 652 nm 处的光密度线性降低，可见检测限低至 10 CFU mL。该传感器无需任何预富集、分离或洗涤步骤，可在 12 分钟内定量检测水、牛奶和尿液样品中的金黄色葡萄球菌。在我们看来，一步比色法分析有望用于金黄色葡萄球菌的实际现场检测。
