金黄色葡萄球菌(S。金黄色葡萄球菌)是一种常见的食源性病原体,对公众健康构成严重威胁。因此,建立一个灵敏、特异的检测食品中金黄色葡萄球菌的平台至关重要。在这里,我们实验室分离的噬菌体SapYZUH5,共价固定在Co3O4上合成SapYZUH5@Co3O4。值得注意的是,SapYZUH5@Co3O4表现出显著的类氧化酶活性,使溶解氧的催化作用产生超氧阴离子自由基,加速TMB显色反应。引入金黄色葡萄球菌后,SapYZUH5@Co3O4的特异性捕获导致抑制其氧化酶样活性并减速3,3',5,5'-四甲基联苯胺(TMB)显色反应。此外,金黄色葡萄球菌可以裂解以释放还原性细菌内容物,可以进一步抑制TMB显色反应。基于这个原则,SapYZUH5@Co3O4+TMB反应体系用于金黄色葡萄球菌的检测,提高了灵敏度,得到一个方程:A=-0.092Log(CSA)+0.79(R2=0.987),超低检测限(LOD)为28CFUmL-1。该系统对金黄色葡萄球菌表现出显著的特异性和抗干扰,由于SapYZUH5对金黄色葡萄球菌的优异亲和力。此外,使用该系统检测实际食品样品中的金黄色葡萄球菌,收率回收率在96.34至109.43%之间,证明了其非凡的准确性。因此,我们提出的将噬菌体共价固定在纳米酶上可以实现食品样品中金黄色葡萄球菌的灵敏、特异的比色测定。
Staphylococcus aureus (S. aureus) is a common foodborne pathogen, posing a serious threat to public health. Consequently, it is crucial to establish a platform for sensitive and specific determination of S. aureus in food. Herein, phage SapYZUH5, isolated by our lab, was covalently immobilized on Co3O4 to synthesize SapYZUH5@Co3O4. Notably, SapYZUH5@Co3O4 exhibited remarkable oxidase-like activity, enabling the catalysis of dissolved oxygen to generate superoxide anion free radicals and accelerate the TMB chromogenic reaction. Upon introduction of S. aureus, specific capture by SapYZUH5@Co3O4 resulted in inhibiting its oxidase-like activity and decelerating the 3,3\',5,5\'-tetramethylbenzidine (TMB) chromogenic reaction. Moreover, S. aureus can be lysed to release the reductive bacterial contents, which can further inhibit the TMB chromogenic reaction. Based on this principle, SapYZUH5@Co3O4 + TMB reaction system was employed for detection with enhanced sensitivity of S. aureus, yielding an equation: A = - 0.092 Log (CSA) + 0.79 (R2 = 0.987), with an ultralow limit of detection (LOD) of 28 CFU mL-1. This system exhibited remarkable specificity and anti-interfere towards S. aureus, owing to the excellent affinity of SapYZUH5 towards S. aureus. In addition, S. aureus in the actual food samples was detected using this system, yielding recoveries ranging from 96.34 to 109.43%, demonstrating its exceptional accuracy. Hence, our proposed covalent immobilization of phage on the nanozyme can realize sensitive and specific colorimetric determination of S. aureus in food samples.