食物致病菌快速检测系统的设计与实现

Design and Realization of a Rapid Food Pathogen Detection System*

设计了食物致病菌快速检测一体化系统。基于抗原-抗体特异性结合的原理,采用TiO2纳米线束为敏感元件设计微生物免疫传感器,以高集成度芯片AD5933设计阻抗检测电路来通过电化学阻抗谱法测量该传感器中TiO2纳米线束的阻抗变化量,实现了致病菌数量的快速检测。以大肠杆菌为例作为实验样本对检测一体化系统的性能进行测试,实验结果表明该检测一体化系统可以快速检测出食物中存在的大肠杆菌,检测周期约为1 h,系统的检测下限为4.5×102cfu/mL,传感器在扫描频率为1 000 Hz～10 000 Hz之间表现出来的重复性较好。

Based on the principle of antigen-antibody and microbial immunosensor using TiO2 nanowire bundle as sensitive material, a rapid food pathogen detection integrated system is designed and realized. The impedance detection circuit adopts a highly integrated chip AD5933 to measure TiO2 nanowire bundle impedance variation with method of electrochemical impedance spectroscopy. E. coli are used as an experimental sample for testing the performance of detection integrated system. The system can rapid detect the E. coli in food in one hour, and the detection limit can reach 4.5 ×102 cfu/mL. The immunosensor of system shows excellent reproducibility between fre- quency of 1 000 Hz - 10 000 Hz.