基于纳米金固定大肠杆菌O157:H7酶免疫传感器的研究

Enzyme immunosensor for E.coli O157:H7 based on nano Au associated immobilization

目的：建立一种快速检测大肠杆菌O157：H7的新型酶免疫传感器。方法：用静电吸附作用和抗原抗体特异性反应将大肠杆菌O157：H7单克隆鼠抗固定在辣根过氧化物酶标记的羊抗鼠IgG／纳米金修饰的玻碳电极表面，制备用于检测大肠杆菌O157：H7的酶免疫传感器。通过循环伏安法和恒电位法测定大肠杆菌O157：H7被固定在电极表面引起的电信号改变进行定量分析。结果：在含0．1mol／L PBS（pH7．4），1 mmol／L二甲氨基甲基二茂铁，0．2mmol／L H2O2，30℃的底液中该酶免疫传感器的检出限为1×10^2cfu／ml，检测线性范围为1×10^3～1×10^5 cfu／ml，相关系数为r=0．997。结论：该传感器制备方法简单，具有灵敏度高、检测时间短、操作简单等优点，在临床医学和环境监测中具有较好的应用价值。

Objective： To develop a rapid and sensitive enzyme immunosensor for detection of Escherichia Coli O157： H7. Methods：The enzyme immunosensor was fabricated by immobilizing monoelonal mouse IgG for E.coli O157：H7 on the sur-face of goat anti-mouse IgG-HRP and nano Au modified glassy carbon electrode through electrostatic adsorption and antigen- antibody specific reaction. The change of electrical signal caused by the capture of E. coil on the electrode surface was detected by Cyclic Vohammetry and Controlled Potential Electrolysis. Results： The linear response of the enzyme immunosensor was in the range of 1 × 10^3 - 1×10^5 cfu/ml with the correlation coefficient of 0.997 and detection limit of 1×10^2 cfu/ml in the solution of 0.1 mol/L PBS （pH 7.4） , 1 mmol/L dimethylamino- methyl-ferroeene, 0.2 mmol/L H2O2 and under 30℃. Conclusion：The method is sample, rapid, sensitive and suitable for the application in the clinical and environmental monitoring.