Covalent modification of glassy carbon electrode with glutamic acid for simultaneous determination of uric acid and ascorbic acid.
Covalent modification of glassy carbon electrode with glutamic acid for simultaneous determination of uric acid and ascorbic acid.
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DOI：
10.1039/b009415n
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
L. Zhang;X. Lin
中科院分区：
文献类型：
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作者：
L. Zhang;X. Lin
采用电化学氧化法制备了谷氨酸共价修饰玻碳电极，并将其应用于尿酸（UA）和抗坏血酸（AA）的催化氧化，使其过电位分别降低约0.2 V和0.3 V。利用其对尿酸和花生四烯酸氧化的强催化作用，该修饰电极将尿酸和花生四烯酸的重叠伏安响应分解为两个清晰的伏安峰，可同时测定混合体系中的尿酸和花生四烯酸。在2 × 10 ~（-6）-4 × 10 ~（-4）mol L ~（-1）和1.0 × 10 ~（-6）-4 × 10 ~（-4）mol L ~（-1）范围内，峰电流与UA和AA浓度呈线性关系，相关系数分别为0.996和0.997。UA和AA的检测限（3 delta）分别为1.1 x 10（-6）mol L-1和9.2 x 10（-7）mol L-1。该修饰电极具有良好的灵敏度、选择性和稳定性，用于人尿样中尿酸和花生四烯酸的同时测定，结果满意。
A novel covalently modified glassy carbon electrode with glutamic acid has been fabricated via an electrochemical oxidation procedure and was applied to the catalytic oxidation of uric acid (UA) and ascorbic acid (AA), reducing the overpotentials by about 0.2 V and 0.3 V, respectively. Based on its strong catalytic function toward the oxidation of UA and AA, the modified electrode resolved the overlapping voltammetric response of UA and AA into two well-defined voltammetric peaks with both cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which can be used for the simultaneous determination of these species in a mixture. The catalytic peak current obtained from DPV was linearly dependent on the UA and AA concentration in the range 2 x 10(-6)-4 x 10(-4) mol L-1 and 1.0 x 10(-6)-4 x 10(-4) mol L-1 with correlation coefficients of 0.996 and 0.997, respectively. The detection limits (3 delta) for UA and AA were 1.1 x 10(-6) mol L-1 and 9.2 x 10(-7) mol L-1, respectively. The modified electrode shows good sensitivity, selectivity and stability, and has been applied to the determination of UA and AA simultaneously in human urine samples with satisfactory results.