中文摘要：

基于电化学聚合将蛋白A（staphylococcal protein A）与吡咯掺杂后共聚于电极表面的新方法设计传感界面，结合采用微机电系统（micro electro mechanical systems，MEMS）技术制备的两电极系统，开发了一种新型的利用电聚合引入蛋白A进而固定抗体、提高检测性能的安培型免疫微传感器，并应用于沙门氏菌（Salmonella typhimurium，S．typhi）的检测。考察了传感器检测沙门氏菌的响应特性，优化了相关实验条件及参数，并结合扫描电镜（scanning electron microscopy，SEM）图像验证了该抗体固定方法的有效性。实验表明，采用电化学聚合方法固定蛋白A进行敏感膜修饰，操作简便省时（〈10min）、可控性强，试剂用量少（10μL），能够有效改善抗体固定效果，提高传感器检测性能，适于微型免疫传感器的表面修饰研究。以此设计的安培型免疫微传感器能够检测100cfu／mL沙门氏菌溶液，具有良好的重复性和特异性.

英文摘要：

A new method based on co-electropolymerizing staphylococcal protein A （SPA） and polypyrrole （PPy） to modify the sensing surface was developed and applied for the detection of Salmonella typhimurium （S. typhi） in a micro amperometric immunosensor, which was an electrochemical system composed of two-electrode system and fabricated based on micro-electro-mechanical systems （MEMS） technology. In the research, the factors influencing the performance of the resulting immunosensor were studied in detail. With visual verification by SEM images, the experiment results demonstrate that this method as a controllable and convenient manipulation can effectively immobilized SPA on the surface of the working electrode for further orientation-controlled immobilization of capture antibodies more rapidly（ in 10 min） with less consumption of reagent（10 μL） , and enhance the property of the sensor. These all prove the feasibility of the method which was proper to sensing surface modification of the micro immunosensor. The studied immunosensor can detect S. typhi with the concentration of 10^2 cfu/ml with acceptable specificity and reproducibility. This work is potential to develop a portable, cost-effective and accurate biosensor for real-time sensing of pathogens in food products.