The accurate, reliable and specific analysis of foodborne pathogenic bacteria is vital for human health and safety. Staphylococcus aureus (S. aureus), as a common bacterium, is regularly found in food, water, and other biological samples. Herein, a signal-off electrochemical DNA sensor (E-DNA sensor) was designed for the sensitive detection of S. aureus amplified with the combination of a DNA walker and Pb²⁺-specific DNAzyme. In this work, vancomycin functionalized gold nanoclusters (Van@Au NCs) and an aptamer strand as identification units were modified at the termini of two proximity probes. Upon the addition of target S. aureus, a dual-recognition binding-induced DNA walker was driven by the formation of Pb²⁺-dependent DNAzyme, achieving the conversion of one S. aureus to many intermediate DNA (T) strands. Then, the released T strands hybridized with methylene blue-tagged hairpin DNA (H-MB) on the electrode. Consequently, the conformational alteration of T strands reduced the electron transfer efficiency of MB to the electrode interface (signal-off). Therefore, sensitive analysis of S. aureus was readily acquired within a range of 10–10⁷ CFU/mL and a low detection limit at 1 CFU/mL. Undoubtedly, dual recognition by aptamer and vancomycin in an integrated scheme brought about a good recognition performance of S. aureus in complex samples, as well as an efficient annihilation of harmful pathogenic bacteria during the experiment.

对食源性致病菌进行准确、可靠和特异性的分析对人类健康和安全至关重要。金黄色葡萄球菌( S. aureus ) 作为一种常见的细菌，经常存在于食物、水和其他生物样品中。在此，设计了一种信号关闭电化学 DNA 传感器（E-DNA 传感器），用于灵敏检测由 DNA walker 和 Pb ²⁺ -特异性 DNAzyme组合扩增的金黄色葡萄球菌。 在这项工作中，万古霉素功能化金纳米簇 (Van@Au NCs) 和作为识别单元的适体链在两个邻近探针的末端进行了修饰。添加目标金黄色葡萄球菌后 , 双重识别结合诱导的 DNA walker 由 Pb ²⁺依赖性 DNAzyme 的形成驱动，实现了一个 金黄色葡萄球菌向许多中间 DNA (T) 链的转化。然后，释放的 T 链与电极上的亚甲基蓝标记的发夹 DNA (H-MB) 杂交。因此，T 链的构象改变降低了 MB 到电极 界面的电子转移效率（信号关闭）。因此，^{在 10-10 7}  CFU/mL 的范围内和 1 CFU/mL 的低检测限范围内很容易获得对金黄色葡萄球菌的灵敏分析毫无疑问，适配体和万古霉素的双重识别在一个集成方案中带来了良好的识别性能。复杂样品中的金黄色葡萄球菌，以及在实验过程中有效消灭有害病原菌。