School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, PR China.
Nanjing Lishui District Hospital of Traditional Chinese Medicine, Nanjing, 211200, PR China; Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, PR China.
Anal Chim Acta. 2024 Nov 15;1329:343259. doi: 10.1016/j.aca.2024.343259. Epub 2024 Sep 18.
Foodborne pathogens such as Escherichia coli and Staphylococcus aureus commonly found in food and water sources are the leading causes of foodborne disease outbreaks, which have become a worldwide issue that can lead to serious health problems and socio-economic losses. Therefore, the development of accurate and timely detection methods for these bacteria is essential to safeguard public health and food safety. However, due to the drawbacks of conventional detection methods such as complex operation, high cost, low specificity and sensitivity, developing efficient and sensitive techniques remains a challenge.
In this study, we developed a fluorescent biosensor based on bacteria-instructed atom transfer radical polymerization (ATRP) for ultrasensitive and specific detection of foodborne pathogenic bacteria. This approach first attaches initiators of ATRP to the surface of carboxylated FeO magnetic beads via transition metal and subsequently utilizes the distinctive copper-binding redox pathway of bacteria to reduce Cu(II) to Cu(I), which activates the surface-initiated polymerization for in situ growth of fluorescent polymer. This signal amplification strategy significantly enhanced the sensitivity of fluorescence analysis performance. Under optimal conditions, there was a perfect linear correlation between the fluorescence signal intensity and the logarithm of the concentrations of S. aureus and E. coli over the range from 10 CFU/mL to 10 CFU/mL, with the detection limits down to 10 CFU/mL for both.
The fluorescent biosensor provides an efficient, sensitive and stable solution for the direct detection of S. aureus/E. coli, confirming the feasibility of the bacterial-instructed ATRP reaction as a signal amplification strategy. This detection method does not require the help of any external stimuli or complex equipment. Moreover, it shows great potential for application in detecting pathogenic bacteria in complex food samples.
食源性病原体，如食品和水源中常见的大肠杆菌和金黄色葡萄球菌，是食源性疾病爆发的主要原因，这已成为一个全球性问题，可能导致严重的健康问题和社会经济损失。因此，开发这些细菌的准确和及时的检测方法对于保障公众健康和食品安全至关重要。然而，由于传统检测方法如操作复杂、成本高、特异性和灵敏度低等缺点，开发高效和敏感的技术仍然是一个挑战。
在这项研究中，我们开发了一种基于细菌指导原子转移自由基聚合（ATRP）的荧光生物传感器，用于超灵敏和特异性检测食源性病原体。该方法首先通过过渡金属将 ATRP 的引发剂附着在羧基化 FeO 磁性珠的表面上，然后利用细菌独特的铜结合氧化还原途径将 Cu(II)还原为 Cu(I)，从而激活表面引发的聚合，进行原位生长荧光聚合物。这种信号放大策略显著提高了荧光分析性能的灵敏度。在最佳条件下，荧光信号强度与金黄色葡萄球菌和大肠杆菌浓度的对数之间存在完美的线性相关性，检测限均低至 10 CFU/mL。
荧光生物传感器为直接检测金黄色葡萄球菌/大肠杆菌提供了一种高效、灵敏和稳定的解决方案，证实了细菌指导的 ATRP 反应作为信号放大策略的可行性。这种检测方法不需要任何外部刺激或复杂设备的帮助。此外，它在检测复杂食品样本中的致病菌方面具有很大的应用潜力。
