Applications Of Carbon Nanotube-Based Electrochemical Sensors For Organophosphorus Pestiside Residues And Catechol Detection

Food analysis and detection is of great significance to ensure food safety, protectthe public’s health and guarantee people’s life safety. In recent years, with highsensitivity, good selectivity, short response time and the advantage of miniatureportable, electrochemical sensing is widely used in the detection of food ingredients,food additives, heavy metals and pesticide residues, etc. This study takes theapplication of nanomaterial-based electrochemical sensors in the field of food testingas the background. This work combines the advantages of carbon nanotube with theadvantages of electrochemical sensor, realizing the rapid determination oforganophosphorus pesticide residues and catechol respectively. The main research andconclusions are as follows：1. Preparation of multi-walled carbon nanotubes/carbon paper (CNTs/CP) compositeWe used carbon paper as the substrate and nickel acetate as the catalyst tosynthesize carbon nanotubes/carbon paper composite electrode by chemical vapordeposition (CVD) method. The prepared dense MCNTs directly grown on carbonpaper is of relatively uniform size with the tube diameter in the range of50~80nmand the length of at least1μm, and possess the morphology of three-dimensionalnetwork structure.2. Application of CNTs/CP electrode for sensitive detection of parathion-methylEmploying CNTs/CP composite as working electrode, we demonstrated thatCNTs/CP electrode has excellent electro catalytic activity towards parathion-methyl.Afterwards, CNTs/CP electrode was used in the rapid determination ofparathion-methyl. CNTs/CP allows for sensitive detection in the range of0.01to1μg/mL with a detection limit of0.0038μg/mL. Besides, CNTs/CP electrode allowsMP detection in cabbage samples. The recovery is94.2%~103.7%with excellentaccuracy and reproducibility.3. Application of CNTs/CP electrode for sensitive detection of catechol The electrocatalytic property of the electrode towards catechol was investigated.The results show that CNTs/CP not only has excellent electrocatalysis to catechol butalso can separate redox peak of catechol and hydroquinone. In the presence ofhydroquinone, CNTs/CP allows for the sensitive and selective determination ofcatechol in the range of1μM to100μM with a detection limit of0.29μM. Besides,CNTs/CP electrode allows catechol determination in tea samples. The RSDs of theresults obtained by electrochemical analysis are3.2%~4.5%with excellent accuracyand reproducibility.