基于复合膜修饰玻碳电极对黄嘌呤的选择性测定

制备了一种新型电化学传感器--聚2,2-联吡啶(Pbpy)/1-苯基-3-甲基-4-(α-呋喃甲酰基)-5-吡唑啉酮(HPM-α-FP)/玻碳(GC)复合膜修饰电极。 运用循环伏安法和脉冲伏安法研究了药物分子黄嘌呤(XN)的电化学行为及反应机理。 与裸GCE和Pbpy/GCE电极相比，复合修饰电极Pbpy/HPM-α-FP/GCE测定XN的氧化峰电流和检测灵敏度均有显著提高,表明聚2,2-联吡啶与酰基吡唑啉酮产生了协同增效作用。 当pH=8,扫速为100 mV/s的条件下，氧化峰电流与黄嘌呤浓度在6×10-7～1×10-5 mol/L和1×10-5～1×10-4 mol/L之间均呈现良好的线性关系，检出限为1×10-8 mol/L。 该修饰电极可用于共存尿酸(UA)、抗坏血酸(AA)体系及实际样品的黄嘌呤含量测定。

Selective Determination of Xanthines Based on Composite Film Modified Glassy Carbon Electrode

A novel electrochemical sensor poly-2,2-bipyridyl(Pbpy)/1-phenyl-3-methyl-4-(2-furoyl)-5-pyrazolone(HPM-α-FP)/glassy carbon(GC) composite film modified electrode was prepared for the determination of xanthine(XN). Cyclic voltammetry and differential pulse voltammetry were used to characterize the electrochemical behavior and to study the reaction mechanism of XN on the electrode. Compared with the bare GCE and Pbpy/GCE, the Pbpy/HPM-α-FP/GCE showed an excellent electrocatalytical effect on the oxidation of XN with a significant increase of the peak current. The results indicated that a synergistic effect existed between Pbpy and HPM-α-FP on the electrode. Linear calibration curve was obtained within the concentration range 6×10-7 to 1×10-5 mol/L and 1×10-5 to 1×10-4 mol/L, respectively, in phosphate buffer solution(PBS) of pH=8.0 with a scan rate 100 mV/s. The detection limit was 1×10-8 mol/L. This electrode could be used for the direct detection of XN in the presence of uric acid(UA) and ascorbic acid(AA), and also the XN in urine samples with satisfactory results.