采用循环伏安法在丝网印刷碳电极表面电聚合聚苯胺/壳聚糖复合膜,利用静电吸附作用固定烯效唑抗体,制备了检测烯效唑的阻抗型免疫传感器。采用循环伏安法和电化学阻抗谱对电极修饰过程进行了表征,并考察了缓冲溶液p H值、温育温度及时间对免疫反应的影响。在优化的条件下研究了免疫传感器的性能。此免疫传感器具有灵敏度高、特异性强、重现性和稳定性好的特点,对烯效唑的线性检测范围为0.01~100 mg/L,相关系数为0.999,检出限为8μg/L(3σ)。白菜样品中添加0.05,0.10和1.0 mg/kg烯效唑,平均回收率为98.5%~104.6%,相对标准偏差为3.3%~4.3%,检测结果与气相色谱法的检测结果相符。
Polyaniline/chitosan composite membrane was modified on the surface of a screen printed carbon electrode by cyclic vohammetry (CV) , and then anti-uniconazole antibodies were immobilized on the electrode based on electrostatic attraction. The impedance immunosensor for the determination of uniconazole was thus constructed. CV and electrochemical impedance spectroscopy (EIS) were used to characterize the electrochemical properties of immunosensor. Several factors affecting the immunoreaction were investigated, including the pH of phosphate buffer saline ( PBS), incubation temperature and time. The performance of the proposed immunosensor was investigated under the optimized conditions. The immunosensor exhibited advantages of high accuracy, high sensitivity and specificity, good reproducibility and stability. The immunosensor could detect uniconazole in a linear range of 0. 01-100 mg/L (R=0. 998 ), and the detection limit was 8 μg/L (30-). The average recoveries were 98.5%-104.6% and the relative standard deviations were 3.3-4.3% at the spiked level of O. 05, 0.10 and 1.0 mg/kg in cabbage, and the detection results were consistent with the results obtained by gas chromatography.