National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
Innovation Academy for Green Manufacture Institute, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
Mikrochim Acta. 2024 Apr 3;191(5):237. doi: 10.1007/s00604-024-06303-6.
An ultra-sensitive fluorescent biosensor based on CDs/QDs@ZIF-8 and microfluidic fluidized bed was developed for rapid and ultra-sensitive detection of multiple target bacteria. The zeolitic imidazolate frameworks (ZIF-8) act as the carrier to encapsulate three kinds of fluorescence signal molecules from the CDs/QDs@ZIF-8 signal amplification system. Besides, three kinds of target pathogenic bacteria were automatically, continuously, and circularly captured by the magnetic nanoparticles (MNPs) in the microfluidic fluidized bed. The neutral NaEDTA solution was the first time reported to not only dissolve the ZIF-8 frameworks from the MNPs-bacteria-CDs/QDs@ZIF-8 sandwich complexes, but also release the CDs/QDs from sandwich complexes with no loss of fluorescence signal. Due to the advantages of signal amplification and automated sample pretreatment, the proposed fluorescent biosensor can simultaneously detect Escherichia coli O157:H7, Salmonella paratyphi A, and Salmonella paratyphi B as low as 10 CFU/mL within 1.5 h, respectively. The mean recovery in spiked milk samples can reach 99.18%, verifying the applicability of this biosensor in detecting multiple bacteria in real samples.
基于 CDs/QDs@ZIF-8 和微流控流化床的超灵敏荧光生物传感器已被开发用于快速和超灵敏检测多种目标细菌。沸石咪唑酯骨架（ZIF-8）作为载体，从 CDs/QDs@ZIF-8 信号放大系统中封装三种荧光信号分子。此外，三种目标致病菌通过微流控流化床中的磁性纳米颗粒（MNPs）自动、连续、循环捕获。中性 NaEDTA 溶液首次被报道不仅可以从 MNPs-细菌-CDs/QDs@ZIF-8 三明治复合物中溶解 ZIF-8 框架，而且还可以从三明治复合物中释放出 CDs/QDs，而不会损失荧光信号。由于信号放大和自动样品预处理的优势，该荧光生物传感器可在 1.5 小时内分别以低至 10 CFU/mL 的浓度同时检测到大肠杆菌 O157:H7、甲型副伤寒沙门氏菌和乙型副伤寒沙门氏菌。在添加牛奶样品中的平均回收率可达到 99.18%，验证了该生物传感器在检测实际样品中多种细菌的适用性。
