基于自组装及纳米磁球放大的大肠杆菌O157：H7的压电免疫检测  

Detection of Escherichia Coli O157：H7 with Piezoelectric Immunosensor Based on the Sandwich Amplified Effect Through Self-assembled Layer and Nanomagnetic Beads

作　　者：吴灵[1] 尚美丽[2] 李雪芳[2] 孔波[2] 

机构地区：[1]株洲师范高等专科学校化学化工系,湖南株洲412007 [2]湖南大学化学化工学院,长沙410082

出　　处：《株洲师范高等专科学校学报》2006年第2期52-56,共5页Journal of Zhuzhou Teachers College

摘　　要：应用压电免疫传感器快速检测了大肠杆菌O157：H7（E．coli O157 ：H7）．将巯基乙酸（MACA）自组装在AT切向的压电金电极上，以N-羟基琥珀酰亚胺（NHS）为反应介质，形成酰氨键固定大肠杆菌抗体．并通过α-甲基丙烯酸（MAA）把抗体修饰在纳米磁球上．采用夹心法将抗原夹在两个抗体间，压电石英晶体交流阻抗（PQCI）和循环伏安法对修饰过程进行了表征，抗原浓度与形成夹心复合物前后的PQCI振动频移相关．其免疲传感器能在3h内检测2×10^3～8×10^8CFU/mL范围内的目标细菌，10^6CFU/mL情况下重复性实验的RSD在7％以下。A piezoelectric immunosensor was developed for rapid detection of Escheriehia coli O157： H7. It was based on the immobilization of affinity-purified antibodies on a layer of mercaptoacetic acid （MACA） self-assembled on an AT-cut quartz crystal＇s Au electrode surface with N-hydroxysuccinimide （NHS） ester as a reactive intermediate. The target bacteria were sandwiched between the primary antigen-specific antibodies and the second antibody which was crosslinked on the methacrylic acid（MAA）-polymerized nanomagnetic beads. The stepwise assembly of the immunosensor was characterized by means of piezoelectric quartz crystal impedance （PQCI） and cyclic voltammetry techniques. The concentration of antigen was correlated with the shift of resonant frequency of PQCI before and after the second antibody binding to the antigen. The r could detect the target bacteria in a range of 2 10^3 -8×10^8 colony-forming units （CFU）/mL within 3 hours, and the sensor reproducibility obtained at 10^6CFU/mL was under 7% R. S. D.

关 键 词：大肠杆菌 夹心免疫传感器 压电石英晶体阻抗 自组装膜 

分 类 号：O657[理学—分析化学] O503[理学—化学]