大肠杆菌O157:H7压电免疫传感器研究及表征

构建了一种可以快速检测大肠杆菌O157:H7的石英微天平(QCM)压电免疫传感器,并用原子力显微镜(AFM)和电化学方法分别对传感的各个步骤进行了表征,整个检测系统均由实验室自己构建。利用QCM的金电极自组装膜特性、抗原抗体的特异性结合和结合后的频差改变(Δf)来检测溶液中O157:H7含量,最后对传感器的再生性进行了初步探索。结果显示,该检测系统可以在1.5h内检测2.0×102~2.0×108CFU/mL的目标菌,并可重复再生使用。

Research and Characterization of QCM Immunobiosensor for Escherichia Coli O157:H7 Detection

A quartz crystal microbalance(QCM) piezoelectric immunobiosensor was developed for rapid detection of Escherichia coli O157:H7.The affinity-purified antibodies to O157:H7 were immobilized onto a monolayer of 16-mercaptohexadecanoic acid(MHDA),which was self-assembled on the Au electrode surface of QCM with N-hydroxysuccinimide(NHS) ester as a reactive intermediate.The binding of target bacteria with the immobilized antibodies would decrease the sensor resonant frequency,and the frequency shift was correlated to the bacterial concentration.The stepwise fabrication and detection of immunosensor were manifested by scanning electron microscopy(SEM) and cyclic voltammetry(CV) techniques.The results show that the 2.0×102~2.0×108 CFU/mL cells can be detected by the sensor within 1.5 h,and the regenerative possibility for the immunosensor was explored.