香草醛在四氧化三铁纳米粒子功能化石墨烯修饰电极上的电化学行为及测定

The Electrochemical Behavior and Determination of Vanillin on the Glassy Carbon Electrode Modified with Fe_3O_4 Nanoparticle Functionalized Graphene

制备了四氧化三铁纳米粒子功能化石墨烯复合膜修饰玻碳电极,用二阶导数线性扫描伏安法研究香草醛在该修饰电极上的电化学行为,以及支持电解质、富集电位、富集时间、扫描速率等对香草醛伏安响应的影响。实验发现,四氧化三铁纳米粒子功能化石墨烯修饰电极测定香草醛具有较高的灵敏度和选择性。在0.1mol·L^(-1) HCl溶液中,香草醛在约936mV(vs.SCE)处产生一灵敏的氧化峰。与未修饰的玻碳电极相比,峰电位负移,峰电流显著增加,说明该修饰电极对香草醛的电化学响应具有很好的催化增敏作用。利用二阶导数线性扫描伏安法进行定量分析,峰电流与香草醛的浓度在1.0×10^(-7) mol·L^(-1)~1.0×10^(-5) mol·L^(-1)和1.0×10^(-5) mol·L^(-1)~1.0×10^(-4) mol·L^(-1)范围内呈良好的线性关系,检出限为6.0×10^(-8) mol·L^(-1)。

In this paper, Fe3O4 nanoparticle functionalized graphene composite film modified glassy carbon electrode was pre- pared. The electrochemical behavior of vanillin at the modified electrode was studied by second-order derivative linear sweep voltammetry. The effect of different buffer solution,accumulation potential, accumulation time and scanning rate on electrode performance was also investigated. The experimental results showed that the modified electrode has high sensitivity and selectivity for the determination of vanillin. In 0.1 mol · L -1 HCl solution,a sensitive oxidation peak of vanillin appeared at 936 mV （vs. SCE）. Compared with the unmodified glassy carbon electrode, the peak current increased greatly and the peak potential moved negatively, indicating that the modified electrode have good catalytic enhancement effect towards the oxidation of vanillin. By the second-derivative linear sweep voltammetry,a good linearity is kept between the oxidation peak current and the concentration of vanillin in the range of 1.0×10 ^-7 mol· L-1 -1.0×10 ^-5 mol· L -1 and 1.0×10^-5 mol · L -1 - 1.0×10^-4 mol · L-1 ,and the detection limit reached 6.0×10 ^-8 mol · L- 1.