抗坏血酸在石墨烯修饰金属有机骨架-离子液体-碳糊电极上的电化学行为及其测定

Electrochemical Behavior of Ascorbic Acid at Graphene and Metal Organic Frameworks-Ionic Liquid-Carbon Paste Electrode and Detection

利用水热法合成铜基金属有机骨架材料(Cu3(BTC)2),用扫描电子显微镜、X射线粉末衍射、红外光谱和热重分析等表征其形貌、结构和热稳定性。按照一定比例将Cu3(BTC)2、碳糊和离子液体(IL)[HPPF6]混合研磨制备Cu3(BTC)2-IL-CPE;利用恒电位法在该电极表面沉积石墨烯(GR)制备GR/Cu3(BTC)2-IL-CPE,采用循环伏安法和差分脉冲伏安法测试工作电极的电化学性能。结果表明GR/Cu3(BTC)2-IL-CPE对抗坏血酸(AA)的电催化性能明显提升,抗坏血酸浓度在0.005~7.0mmol/L范围时氧化峰电流与浓度呈线性关系,检测限为0.0017mmol/L(3σ)。该修饰电极成功应用于市售维生素C片剂的测定,证明本方法具有良好的准确性和选择性。

The copper based metal organic frameworks (Cu3(BTC)2) is prepared by solvothermal method, which were char. acterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravi. metric analyzer. Cu3(BTC)2 were mixed with ionic liquid (IL) and graphitic power to get Cu3(BTC)2-IL-CPE. Graphene was successfully modified to the Cu3(BTC)2-IL-CPE surface by electrodeposition methods, and then the GR/Cu3(BTC)2-ILCPE was prepared. The sensitive oxidation response of ascorbic acid (AA) by cyclic voltammetric (CV) and differential pulse voltammetry (DPV) was verified. A voltammetric linear response for AA was obtained in the concentration range of 0.005 ~ 7.0 mmol/L with a detection limit of 0.0017 mmol/L (3σ). The proposed method could be successfully utilized for AA detection in vitamin C tablets.