Yang Yuemeng, Wu Tingting, Xu Li-Ping, Zhang Xueji
Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China.
Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China.
Talanta. 2021 May 1;226:122132. doi: 10.1016/j.talanta.2021.122132. Epub 2021 Jan 22.
Staphylococcus aureus is one of the most important food-borne bacterial pathogens and causes numerous illnesses. In this work, we report a sensitive and highly selective magnetic-aptamer biosensor based on a personal glucose meter (PGM) platform for the detection of Staphylococcus aureus. The aptamer for Staphylococcus aureus was immobilized on the magnetic bead by hybridization with the capture probe P. In the presence of Staphylococcus aureus, the aptamer was dissociated from the magnetic bead. Then the capture probe was exposed and could be hybridized with a biotinylated probe to trigger the DNA hybridization chain reaction (HCR), thus achieving the signal amplification. The concentration of streptavidin-labeled invertase can be read by PGM, thus can lead to the portable quantitative detection of Staphylococcus aureus. After optimization of various conditions, 5 μM probe P, the MB-P reaction time for 36 h, the competition time for 60 min, 0.5 μM H1 & H2, 0.5 M sucrose and the sucrose invertase catalytic reaction time for 50 min was chosen to achieve the better sensor performance. Under the optimal conditions, the fabricated sensor offers high sensitivity with the limit of detection about 2 CFU/mL. This sensitive PGM based sensor could successfully evaluate the Staphylococcus aureus concentration in real food samples, and the results are consistent with those obtained by using plate counting methods. Moreover, the PGM sensor can greatly reduce the required time compared to the plate counting methods. The fabricated sensor supplies an ideal solution for rapid portable detection of bacterial pathogens and holds its potential use in the quality control for agriculture and food enterprises, entry-exit inspection and quality testing for food.
金黄色葡萄球菌是最重要的食源性细菌病原体之一，可引发多种疾病。在本研究中，我们报道了一种基于个人血糖仪（PGM）平台的灵敏且高选择性的磁珠适配体生物传感器，用于检测金黄色葡萄球菌。金黄色葡萄球菌的适配体通过与捕获探针P杂交固定在磁珠上。在金黄色葡萄球菌存在的情况下，适配体从磁珠上解离。然后捕获探针暴露出来，并可与生物素化探针杂交以触发DNA杂交链式反应（HCR），从而实现信号放大。链霉亲和素标记的转化酶的浓度可通过PGM读取，进而实现对金黄色葡萄球菌的便携式定量检测。在优化各种条件后，选择5 μM探针P、MB - P反应时间36小时、竞争时间60分钟、0.5 μM H1和H2、0.5 M蔗糖以及蔗糖转化酶催化反应时间50分钟，以实现更好的传感器性能。在最佳条件下，所制备的传感器具有高灵敏度，检测限约为2 CFU/mL。这种基于PGM的灵敏传感器能够成功评估实际食品样品中金黄色葡萄球菌的浓度，结果与平板计数法获得的结果一致。此外，与平板计数法相比，PGM传感器可大大缩短所需时间。所制备的传感器为细菌病原体的快速便携式检测提供了理想的解决方案，在农业和食品企业的质量控制、食品出入境检验和质量检测中具有潜在的应用价值。
