Study On Electrochemical Sensor Based On Poly(3,4-Ethylenedioxythiophene) And Zirconium Nanocomposites

The widespread use of pesticides,herbicides,disinfectants and antibiotics in agriculture and medicine has greatly promoted agricultural and medical progress.However,pesticide and antibiotic residues in water resources,soil,agricultural products are major environmental pollution problems,which seriously threaten human health.Therefore,the application of modern technology to detect and monitor pesticide and antibiotic residues in the environment is of great significance to the environment and human health.Electrochemical sensor technology is a suitable method to detect pesticide and antibiotic,due to the electrochemical signal and feedback signal,electrochemical sensor has advantages of timely response,sensitive and accurate result,and simple operation.Electrode materials are the most important components of the electrochemical sensor,which act as recognizer of the target moleculeand signal converter,affecting the performance of the sensor.In this paper,two specific electrochemical sensors were constructed by using a composite of zirconiumbasednanomaterialsandaconductivepolymer,poly3,4-ethylenedioxythiophene,as electrode modification material.The main research contents are as follows.1)An electrochemical sensor for the detecting methyl parathion was constructed by modifying ITO electrode with zirconia nanoparticles which can specificly adsorb methyl parathion and poly3,4-ethylenedioxythiophene polymer with good electrical conductivity and electrocatalytic activity.Poly 3,4 ethylenethiophene was electrodeposited on ITO electrodes,then it combine zirconia nanoparticles and chitosan membrane layer,the ZrO₂-CHIT/PEDOT/ITO electrode was fabricated.The structure and morphology of ZrO₂-CHIT/PEDOT/ITO electrode were characterized by X-ray diffractometer and scanning electron microscope?SEM?.The zeta potentials of ZrO₂ nanoparticles in different pH value solution were characterized by laser particle size analyzer,the adsorption effect of ZrO₂ to methyl parathion was characterized by ultraviolet-visible spectrophotometer.cyclic voltammetry and square wave voltammetry were used for measuring the electrochemical response of methyl parathion on modified electrode,the experimental conditions were optimized,under the optimized conditions of modified electrodes,the detection performance of electrode for methyl parathion were measured by square wave voltammetry,the anti-interference and the reproducibility of the sensor were further tested.2)A kind of MOF material,PCN-222,was prepared by hydrothermal method.Its structure and morphology were characterized by X-ray diffractometer and scanning electron microscope,and zeta potential was characterized by laser particle size analyzer.PCN-222 will be used for solid adsorption materials of chloramphenicol.ITO electrodes were modified with poly 3,4 ethylenethiophene film and composites of chitosan and PCN-222.The PCN-222-CHIT/PEDOT/ITO electrode was used as electrochemical sensor for chloramphenicol.The structure and morphology of PCN222-CHIT/PEDOT/ITO electrode were characterized by scanning electron microscope?SEM?.The zeta potentials of PCN-222 nanoparticles in different pH value solution were characterized by laser particle size analyzer.The adsorption effect of PCN-222 to chloramphenicol was characterized by ultraviolet-visible spectrophotometer.Cyclic voltammetry and differential pulse voltammetry were used to study electrochemical properties of the PCN-222-CHIT/PEDOT/ITO electrode and the electrochemical response to chloramphenicol.Under the optimized experimental conditions,the fabricated PCN-222-CHIT/PEDOT/ITO electrode sensor used for detecting chloramphenicol by differential pulse voltammetry,obtaining its linear range and detection limit.The sensor shown superior anti-interference and the reproducibility,and further used for of chloramphenicol detection in the real samples.