基于多孔碳球修饰硼掺杂金刚石电极的甲基对硫磷检测

Determination of methyl parathion based on porous carbon spheres-modified boron-doped diamond electrode

目的研究甲基对硫磷检测的快速检测方法。方法 用多孔碳球材料修饰硼掺杂金刚石(BDD)电极,将乙酰胆碱酯酶(ACh E)固定在修饰电极表面制得酶传感器,用于甲基对硫磷的检测。对所制备的酶传感器进行电化学表征,对实验参数进行优化。结果 底物氯化乙酰胆碱的产物在ACh E/BDD电极和ACh E/多孔碳球/BDD电极上的氧化峰电流分别为0.4930μA和1.102μA,峰电流提高了123.53%。在ACh E/多孔碳球/BDD电极上,建立抑制率与甲基对硫磷浓度的负对数的对应关系,在浓度范围10-10~10-7g/L内呈良好的线性关系,线性方程为Y=-13.20297X+148.375,相关系数R2为0.9985。按抑制率为10%计算检出限为3.02×10-12g/L。对实际样品黄瓜汁进行检测,样品回收率为92.60%~102.00%。结论 此方法简单、快速、灵敏度高,适合用于实际样品中的甲基对硫磷残留分析。

Objective To study the rapid determination method of methyl parathion.MethodsPorous carbon spheres were prepared and used to modify boron-doped diamond (BDD) electrode. The acetylcholines-terase (AChE) was fixed to the modified electrode surface, and then was used to detect methyl parathion. The ob-tained enzyme sensor was characterized electrochemically, and the experimental parameters were optimized. ResultsThe oxidation peak current of ATCl product was 0.4930μA and 1.102μA on the AChE/BDD electrode and AChE/porous carbon spheres/BDD electrode, and the peak current was enhanced by 123.53%. The sensor had a good linear relationship with the concentration of methyl parathion in the range of 10-10~10-7g/L, with a linear equation ofY=-13.20297X+148.375 (R2=0.9985) and a detection limit of 3.02×10-12 g/L. The sensor could be used for detecting cucumber juice samples, with recovery rate of 92.60%~102.00%.ConclusionThis method is sim-ple, fast, and highly sensitive, and it is suitable for the detection of methyl parathion.