咖啡因的碳纳米管负载纳米铂修饰电极的伏安法测定  

Voltammetric Determination of Caffeine at Nano Platinum-Supported Carbon Nanotubes Modified Glassy Carbon Electrode

作　　者：卫应亮[1,2] 张路平[1] 邵晨[1] 李超[1] 

机构地区：[1]郑州轻工业学院材料与化学工程学院,河南郑州450002 [2]洛阳理工学院环境工程与化学系,河南洛阳471023

出　　处：《分析测试学报》2009年第5期597-600,共4页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(20871107);河南省杰出青年科研基金资助项目(0612002700);河南省基础与前沿技术研究计划资助项目(072300420010)

摘　　要：将碳纳米管(CNTs)分散在疏水性表面活性剂双十六烷基磷酸(DHP)中形成稳定、均相的分散液,制备了一种新型的碳纳米管负载纳米铂修饰电极(Pt/CNTs/GCE)。采用差分脉冲伏安法研究了咖啡因在该电极上的电化学行为;在0.01mol/L的H2SO4溶液中,咖啡因在Pt/CNTs/GCE修饰电极上于1.33V处出现一灵敏的氧化峰;该修饰电极对咖啡因的氧化有良好的电催化活性,在最佳测试条件下,氧化峰电流与咖啡因的浓度在1.0×10-6～1.0×10-4mol/L范围呈现良好的线性关系,检出限达2×10-7mol/L;该修饰电极表现出良好的稳定性和重现性,5次平行测量的RSD为2.03%;计时电量法求得扩散系数为3.58×10-5cm2/s。方法用于茶叶等样品中咖啡因含量的测定,结果令人满意。A novel type of nano platinum - supported carbon nanotubes modified glassy carbon （ Pt/ CNTs/GC） electrode was prepared by using the CNTs dispersed in dihexadecyl hydrogen phosphate （DHP） solution. The electrochemical behavior of caffeine at the Pt/CNTs/GC electrode was studied by differential pulse voltammetry. The result showed that a sensitive oxidation peak was observed at 1.33 V in 0. 01 mol/L H2SO4 buffer solution, indicating that the Pt/CNTs/GC electrode exhibited good electrocatalytic activity towards the oxidation of caffeine. Under optimum conditions, the oxida- tion peak current was proportional to the concentration of caffeine in the range of 1.0 ×10-6 - 1.0 ×10-4 mol/L with a correlation coefficient of 0. 999 5 and a detection limit of 2 ×10-7 mol/L. The modified electrode showed good stability and reproducibility. The relative standard deviation （RSD） of five measurements was 2.03% for 1.0×10-5 mol/L caffeine. The diffusion coefficient was calculated to be 3.58×10-5 cm2/s by chronocoulometry. The modified electrode was applied to the determina- tion of caffeine in real samples with satisfactory results.

关 键 词：咖啡因 碳纳米管 纳米铂 修饰电极 电催化 

分 类 号：O657.15[理学—分析化学]