基于夹心法的DNA生物传感器用于检测大肠埃希菌O157:H7 stx2基因

Based on sandwich-mode DNA biosensor for detection of stx2 gene of Escherichia coli O157:H7

目的构建DNA生物传感器用于大肠埃希菌O157:H7的快速检测。方法基于双探针夹心法,结合酶标生物电催化反应技术和计时电流的电化学法检测大肠埃希菌O157:H7的stx2基因。结果在最佳反应条件下,DNA探针能较好地固定于金电极表面;探针标记链酶亲合素后,检测信号明显增强。DNA生物传感器具有良好的特异性,其值可达6.25×10-8mol/L。结论构建的DNA生物传感器特异性和灵敏度高,可为大肠埃希菌O157:H7的快速检测提供新的方法。

Objective To construct a DNA biosensor for detection of E. coli O157： H7. Methods The DNA biosensor based on sandwich-mode was constructed combined with electrocatalytic enzyme reaction and amperometric method to detect stx2 gene of E. coli O157： H7. Results Under the optimum conditions,capture probe secured to the surface of gold electrode and current signal was enhanced significantly with labeling avidin-HRP. The specificity of the biosensor was preferable and its detection limit reached to 6. 25 ×10- 8mol / L. Conclusion The DNA sensor constructed in this study exhibited high specificity and sensitivity so it may provide a new way for rapid detection of E. coli O157： H7.