Pathogenic bacterial infections, even at extremely low concentrations, pose significant threats to human health. However, the challenge persists in achieving high-sensitivity bacterial detection, particularly in complex samples. Herein, we present a novel sandwich-type electrochemical sensor utilizing bacteria-imprinted polymer (BIP) coupled with vancomycin-conjugated MnO₂ nanozyme (Van@BSA-MnO₂) for the ultrasensitive detection of pathogenic bacteria, exemplified by Staphylococcus aureus (S. aureus). The BIP, in situ prepared on the electrode surface, acts as a highly specific capture probe by replicating the surface features of S. aureus. Vancomycin (Van), known for its affinity to bacterial cell walls, is conjugated with a Bovine serum albumin (BSA)-templated MnO₂ nanozyme through EDC/NHS chemistry. The resulting Van@BSA-MnO₂ complex, serving as a detection probe, provides an efficient catalytic platform for signal amplification. Upon binding with the captured S. aureus, the Van@BSA-MnO₂ complex catalyzes a substrate reaction, generating a current signal proportional to the target bacterial concentration. The sensor displays remarkable sensitivity, capable of detecting a single bacterial cell in a phosphate buffer solution. Even in complex milk matrices, it maintains outstanding performance, identifying S. aureus at concentrations as low as 10 CFU mL^–1 without requiring intricate sample pretreatment. Moreover, the sensor demonstrates excellent selectivity, particularly in distinguishing target S. aureus from interfering bacteria of the same genus at concentrations 100-fold higher. This innovative method, employing entirely synthetic materials, provides a versatile and low-cost detection platform for Gram-positive bacteria. In comparison to existing nanozyme-based bacterial sensors with biological recognition materials, our assay offers distinct advantages, including enhanced sensitivity, ease of preparation, and cost-effectiveness, thereby holding significant promise for applications in food safety and environmental monitoring.

中文翻译：

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使用细菌印迹聚合物和万古霉素缀合的 MnO2 纳米酶在单细胞水平上对金黄色葡萄球菌进行超灵敏和高选择性检测


致病细菌感染，即使浓度极低，也会对人类健康构成重大威胁。然而，实现高灵敏度细菌检测仍然存在挑战，特别是在复杂样品中。在此，我们提出了一种新型夹心型电化学传感器，利用细菌印迹聚合物（BIP）与万古霉素共轭的 MnO ₂ 纳米酶（Van@BSA-MnO ₂ ）耦合，实现超灵敏检测致病菌，例如金黄色葡萄球菌（S. aureus）。在电极表面原位制备的 BIP 通过复制金黄色葡萄球菌的表面特征充当高度特异性的捕获探针。万古霉素 (Van) 以其对细菌细胞壁的亲和力而闻名，通过 EDC/NHS 化学与牛血清白蛋白 (BSA) 模板的 MnO ₂ 纳米酶结合。所得的 Van@BSA-MnO ₂ 复合物作为检测探针，为信号放大提供了有效的催化平台。与捕获的金黄色葡萄球菌结合后，Van@BSA-MnO ₂ 复合物催化底物反应，产生与目标细菌浓度成比例的电流信号。该传感器表现出卓越的灵敏度，能够检测磷酸盐缓冲溶液中的单个细菌细胞。即使在复杂的乳基质中，它也能保持出色的性能，识别浓度低至 10 CFU mL ^–1 的金黄色葡萄球菌，无需复杂的样品预处理。此外，该传感器表现出优异的选择性，特别是在区分目标金黄色葡萄球菌和浓度高出 100 倍的同属干扰细菌方面。 这种创新方法采用全合成材料，为革兰氏阳性菌提供了多功能且低成本的检测平台。与现有的基于纳米酶的生物识别材料细菌传感器相比，我们的检测方法具有明显的优势，包括增强的灵敏度、易于制备和成本效益，从而在食品安全和环境监测方面的应用具有重大前景。