多壁碳纳米管/PEDOT复合修饰电极的制备及对苯二酚的测定

Preparation of Multi-walled Carbon Nanotube/PEDOT Composite Modified Electrode and Determination of Hydroquinone

采用循环伏安法和悬凃法,在玻碳电极表面进行聚(3,4)-乙撑二氧噻吩(PEDOT)和多壁碳纳米管修饰,制备多壁碳纳米管-聚(3,4)-乙撑二氧噻吩复合修饰电极。通过扫描电镜观察复合电极的表面形貌,通过电化学阻抗谱(EIS)和循环伏安(CV)对复合电极进行电化学表征,用差分脉冲法(DPV)研究对苯二酚浓度与峰电流之间的线性关系。实验结果表明,制备的复合修饰电极对对苯二酚有明显的电催化作用,氧化还原峰电流明显增大;在p H为7.0的磷酸缓冲液(PBS)里,对苯二酚的峰电流最大。在1×10^(-5)~5×10^(-4)mol/L对苯二酚的浓度范围内,复合修饰电极的氧化峰电流值与浓度呈线性关系,其线性方程为y=47.95+0.0979x,R2=0.961,检出限为1.9×10^(-6)mol/L。制备的复合修饰电极能够增强电化学信号,具有较好的稳定性。

A layer of poly(3,4-ethylenedioxythiopene)(PEDOT)was deposited on the glassy carbon electrode by cyclic voltammetry and multiwall carbon nanotubes(SWCNT)were coated on the prepared electrode surface to obtain the composite film modified electrode.The microstructure of the composite electrode was characterized by scanning electron microscopy.The electrochemical characteristics of the composite electrode were investigated by electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV).The linear equation between hydroquinone concentration and the current intensities of oxidation peaks was evaluated by differential pulse method(DPV).It was found that the prepared composite modified electrode has obvious electrocatalytic effect on hydroquinone,and the peak current increases obviously.In the phosphate buffer(PBS)with pH of 7.0,the peak current of hydroquinone is the largest.The oxidation peak current value and concentration of hydroquinone show a linear relationship in the range of 1×10^(-5)~5×10^(-4)mol/L,and the linear equation is y=47.95+0.0979x.R2=0.961,the detection limit was 1.9×10^(-6)mol/L.The prepared composite modified electrode can help amplify the electrochemical signal and exhibited good stability.