生物免疫传感器检测迟缓爱德华氏菌研究

Research of immuno-biosensor for Edwardsiella tarda detection

迟缓爱德华氏菌(E.tarda)是最为严重的水产动物致病菌之一,准确、即时的检测手段是预防控制该菌传播的关键所在。通过量子点(QDs)标记E.tarda单克隆抗体(Ab),利用生物免疫传感器技术实现E.tarda的快速、特异性检测。结果显示,QDs-Ab的荧光通过加入氧化石墨烯(GO)产生淬灭,构建了捕获目标细菌的探针,GO最适淬灭浓度为60μg/L。细菌捕获探针中加入E.tarda后,能够检测到重新恢复强度的橙色荧光。针对E.tarda设计的生物免疫传感器的特异性,选取灿烂弧菌、溶藻胶弧菌、副溶血弧菌和嗜水气单胞菌作为对照,结果显示,对照组不能明显引起荧光强度的改变,而实验组却能显著提高荧光强度。本研究建立的基于荧光能量共振转移(FRET)的具有高灵敏度和特异性的生物传感器检测方法在细菌的早期诊断中有良好的应用潜质。

Edwardsiella tarda has been recognized as one of the most serious aquatic animal pathogens. Real-time and accurate means of detection is the key for prevention and control of spread of Edwardsiella tarda. In this present work,a novel detection strategy is designed to realize rapid and specific determination of Edwardsiella tarda by labeling Edwardsiella tarda monoclonal antibody（ Ab） with QDs. The results show that the fluorescence of these QDs-Ab bioconjugates is quenched by GO to produce a bacterium capture probe. And the optimal quenched concentration of Graphene oxide is 60 μg/L. When the bacterium capture probe is exposed to the targets of Edwardsiella tarda,orange color fluorescence is turned on by releasing the QDs-Ab due to the antibody antigen combination. The specificity of the FRET sensor towards Edwardsiella tarda is examined by comparing with controls such as Vibrio splendidus,Vibrio alginolyticus,Vibrio parahaemolyticus and Aeromonas hydrophila with the same condition. The control group can not cause obvious fluorescence alteration,while the experimental group results in significant fluorescence enhancement. Therefore,the sensor has good potential to expand its application to the early diagnosis determination of bacterium.