中文摘要：

采用化学共沉淀技术制备磁性Fe3O4-Au纳米粒子复合物（Fe3O4-AuNPs）,并以此磁性纳米复合物和碳纳米管（CNTs）构建用于快速检测对氧磷的乙酰胆碱酯酶（AChE）生物传感器。通过磁力作用将Fe3O4-AuNPs纳米粒子固定在自制的磁铁/玻碳电极（MGCE）上,并以此作为AChE的载体。分别通过X射线衍射、振动样品磁强和透射电镜表征了磁性纳米粒子复合物Fe3O4-AuNPs的成分、磁性及其形貌特征。利用电化学交流阻抗（EIS）、循环伏安法和微分脉冲伏安法（DPV）表征了自制的MGCE修饰电极以及生物传感器（AChE/Fe3O4-AuNPs/CNTs/MGCE）的电化学特征,建立了用该生物传感器微分脉冲伏安法检测对氧磷的方法。在最佳实验条件下,酶抑制率与对氧磷浓度的对数在3.6×10-6～2.9×10-2mol/L范围内呈线性关系,检出限为1.6×10-7mol/L。用提出的方法对实际水样中的对氧磷进行加标回收实验,回收率为98.0%～107%。

英文摘要：

An acetylcholinesterase biosensor for the rapid detection of paraoxon was developed based on composites of magnetic Fe3O4-Au nanoparticles（ Fe3O4-AuNPs） prepared by chemical co-precipitation. This magnetic nanoparticle composites and carbon nanotubes（ CNTs） were immobilized on a home-made magnet /glassy carbon electrode（ MGCE） and served as matrix for immobilizing AChE.The chemical composition,magnetic properties and morphology of magnetic nanoparticles composite Fe3O4-AuNPs were characterized by X-ray diffraction,vibrating sample magnetometry and transmission electron microscopy,respectively. The electrochemical characteristics of home-made MGCE and enzyme biosensor were characterized by electrochemical impedance spectroscopy（ EIS）,cyclic voltammetery,and differential pulse voltammetry（ DPV）. The determination of paraoxon using the biosensor were investigated by DPV. Under the optimal conditions,the inhibition efficiency of the immobilized AChE was proportional to the logarithm of paraoxon concentration over the range of 3. 6 × 10-6-2. 9 × 10-2mol /L with a detection limit of 1. 6 × 10-7mol /L. The proposed method was successfully applied in the determination of paraoxon in real water sample with recoveries of 98. 0%-107%.