制备了一种纳米氧化铝/石墨烯（Al2O3/Gr）复合膜修饰的对硫磷电化学传感器，用电子扫描显微技术（SEM）表征了复合膜的表面形貌，用循环伏安法研究了对硫磷（PT）在复合膜及单层膜修饰的电极表面的电化学行为。研究表明：在pH为5.2的醋酸缓冲液中开路富集2.5 min时，PT的还原峰电流最大。在优化实验条件下， PT的还原峰电流ipc与其浓度在0.05~60μM范围内呈良好线性关系，线性回归方程为ipc（μA）=5.666+0.6937 c （μM），R=0.9964，检测限可达20 nM（ S/N=3）。该传感器稳定性好、重现性佳，且具有一定抗干扰能力。用加标回收法测量新鲜小白菜样品中PT含量，回收率在94.5%~101.0%，结果令人满意。%A parathion electrochemical sensor based on nano-Al2O3/graphene composite film modified electrode has been developed. Scanning electron microscopy(SEM)was used to characterize the surface morphology of nano-Al2O3 film and nano-Al2O3/graphene composite film. The electrochemical behavior of parathion at the sensor was investigated by cyclic voltammetry(CV)and linear sweep voltammetry(LSV). Compared with bare glassy carbon electrode ,the sensor showed good catalysis for the redox of parathion due to porous structure of nano-Al2O3 and excellent conductivity of graphene. The optimized experimental conditions were obtained. The results indicated that the LSV responses of parathion were linear with concentrations in the range of 0. 05 to 60μM with linear equation of i pc (μA)=5. 666+0. 693 7 c(μM) in pH 5. 2 acetate buffer with open circuit accumulation for 2.5 min. The detection limit was 20 nM ( S/N =3)and R=0. 996 4. The sensor exhibited high sensitivity and good selectivity as well as certain anti-interference ability. It was applied to the determination of residual parathion in fresh cabbage sample with the recovery of 94. 5%~101. 0%. The results were satisfactory.
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