Fast detection of E. coli with a novel fluorescent biosensor based on a FRET system between UCNPs and GO@Fe3O4 in urine specimens.
Fast detection of E. coli with a novel fluorescent biosensor based on a FRET system between UCNPs and GO@Fe3O4 in urine specimens.
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DOI：
10.1039/d1ay00320h
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
Yuan Yao;G. Xie;Xin Zhang;Jinshan Yuan;Yulei Hou;Hui Chen
中科院分区：
文献类型：
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作者：
Yuan Yao;G. Xie;Xin Zhang;Jinshan Yuan;Yulei Hou;Hui Chen
基于纳米材料的生物传感器是病原菌快速检测的研究热点。本文构建了一种基于FRET系统的“开启”荧光生物传感器，用于快速检测代表性病原微生物大肠杆菌。大肠杆菌，导致大多数尿路感染。该生物传感器是利用合成的UCNPs作为荧光供体，在复杂生物样品中具有稳定的发光性能，GO@Fe3O4作为受体，具有良好的吸附能力和荧光猝灭能力。选择特异性ssDNA作为识别大肠杆菌的适体。将大肠杆菌固定在UCNPs上形成UCNP-Apt纳米探针。通过核酸适配体与GO之间的π堆积作用，纳米探针被吸附在GO@Fe3O4表面。在E.大肠杆菌中，UCNP-Apt纳米探针由于适体与细菌的特异性识别而从GO@Fe3O4上脱离，导致荧光恢复明显，且细菌浓度与荧光信号强度呈正相关;这样的“开启”信号输出模式保证了优异的精度。此外，GO@Fe3O4的简单磁性分离简化了操作过程，有助于传感器在30分钟内检测细菌，线性范围为103至107 CFU mL-1，检测限为467 CFU mL-1。回收率测试结果也表明，该传感器对复杂生物样品中病原微生物的快速检测具有临床应用潜力。
Biosensors based on nanomaterials are becoming a research hotspot for the rapid detection of pathogenic bacteria. Herein, a "turn-on" fluorescent biosensor based on a FRET system was constructed for the fast detection of a representative pathogenic microorganism, namely, E. coli, which causes most urinary tract infections. This biosensor was constructed by utilizing synthesized UCNPs as fluorescent donors with stable luminescence performance in complex biological samples and GO@Fe3O4 as a receptor with both excellent adsorption ability and fluorescence quenching ability. A specific ssDNA selected as an aptamer which could recognize E. coli was immobilized on the UCNPs to form UCNP-Apt nanoprobes. The nanoprobes were adsorbed on the surface of GO@Fe3O4 through the π-stacking interactions between aptamers and GO. In the presence of E. coli, UCNP-Apt nanoprobes detached from GO@Fe3O4 due to the specific recognition of aptamers and bacteria, resulting in obvious fluorescence recovery, and the concentration of bacteria was positively correlated with the intensity of the fluorescence signal; such a "turn-on" signal output mode ensures excellent precision. In addition, the easy magnetic separation of GO@Fe3O4 simplifies the operation process, helping the sensor detect bacteria in 30 minutes with a linear range from 103 to 107 CFU mL-1 and a limit of detection of 467 CFU mL-1. Moreover, recovery test results also showed that the sensor has clinical application potential for the rapid detection of pathogenic microorganisms in complex biological samples.