基于多壁碳纳米管修饰四氧化三钴传感器检测白菜中杀螟硫磷

目的 基于多壁碳纳米管修饰四氧化三钴(Co3O4@MWCNTs)纳米复合物，成功构建了一种用于白菜样品中快速检测杀螟硫磷的电化学传感器。方法 将以醋酸钴水合物为钴源，而采用简便水热法制备的四氧化三钴纳米颗粒与多壁碳纳米管复合成Co3O4@MWCNTs纳米材料，以Co3O4@MWCNTs纳米复合物修饰的玻碳电极(GCE)为工作电极，利用循环伏安法(CV)研究了杀螟硫磷在修饰电极界面的电化学行为；并通过逐步优化支持电解质的PH值、复合材料质量比等检测条件。结果 实验结果表明，Co3O4@MWCNTs/GCE改性电极能够实现对杀螟硫磷的灵敏检测。在最优条件下，该传感器的线性浓度范围为1.0×10-5~1.4×10-4 mol/L，R2=0.991，检出限为7.8×10-8 mol/L(S/N=3)；并成功用于实际白菜样品中杀螟硫磷的加标回收实验，回收率为93.7%~97.6%。结论 Co3O4和MWCNTs复合后制备的传感器不仅可以选择性识别杀螟硫磷，达到快速检测目标物的需求。而且，其电化学性能也得到了明显的提升，展现出较高的灵敏度，表明该传感器在现场检测中具有非常大的应用潜力。

Detection of fenitrothion in cabbage based on multi-walled carbon nanotubes modified with cobalt oxide sensor

Objective To construct an electrochemical sensor for the rapid detection of fenitrothion in cabbage samples based on multi-walled carbon nanotubes modified with cobalt oxide (Co3O4@MWCNTs) nanocomplexes. Methods Using cobalt acetate hydrate as the cobalt source, the cobalt oxide nanoparticles prepared by a facile hydrothermal method were compounded with multi-walled carbon nanotubes; and the electrochemical behaviour of fenitrothion at the modified electrode interface was investigated by cyclic voltammetry using a glassy carbon electrode (GCE) modified with Co3O4@MWCNTs nanocomplexes as the working electrode; the experimental conditions were also gradually optimized, such as the pH value of the supporting electrolyte and the mass ratio of the composite materials. Results Co3O4@MWCNTs/GCE modified electrode could detect fenitrothion sensitively. Under the optimum conditions, this sensor in the linear concentration range of 1.0×10?5?1.4×10?4 mol/L, R2=0.991, and the limit of detection was 7.8×10?6 mol/L (S/N=3); it was successfully used in the spiked recovery experiments of fenitrothion in real cabbage samples with the recoveries of 93.7%?97.6%. Conclusion The sensor prepared by the composite of Co3O4 and MWCNTs can not only selectively identify fenitrothion and achieve the need for rapid detection of the target. But also, it has good electrochemical performance and high sensitivity, indicating that the sensor has great promising application on-the-spot detection.