摘要
采用电化学氧化法将2-氨基乙硫醇共价键合在玻碳电极表面，并采用X-射线光电子能谱和电化学方法对其进行了表征．2-氨基乙硫醇修饰的玻碳电极对尿酸显示出较好的催化氧化作用，表现在尿酸氧化过电位的负g（230mV）和峰电流的增加．并且，尿酸的氧化峰电流在8．0×10^-6～2．0×10^-4mol／L内随尿酸浓度的增加而线性增大，相关系数为0．9976，检测限为4．8×10^-7mol／L．该法被成功地用于人尿中尿酸含量的测定．另外，该修饰电极可将常规电极上尿酸和抗坏血酸重叠的氧化波进行有效的分离，由此，该法有望用于两者的同时测定．
2-Aminoethanethiol （2-AET） was covalently grafted on glassy carbon electrode （GCE） by amine cation radical formation in the electro-oxidation process of the amino-containing compound. The improved electrochemical behavior of uric acid at the modified electrode showed that the electrode modified with 2-AET exhibited efficient elec- tro-catalytic oxidation for uric acid. The anodie overpotential was reduced about 230 mV compared with that obtained at bare GCE. The enhanced voltammetrie response can be used for the determination of uric acid. The hnear calibration curve was obtained over the range from 8.0 × 10 ^-6 mol/L to 2.0 ×10^ -4 mol/L with slop （μA/μM） and coefficient correlation of 3.5 and 0. 9976, respectively. The detection limit （3σ） for uric acid was 4.8 × 10^-7 mol/L. The relative standard derivation was 2.7% at a concentration of 5.0 ×10^ -5 mol/L uric acid. The practical utility of the proposed method was demonstrated by the measurement of uric acid in human urine without any preliminary treatment. Moreover, the catalytic effect of 2-AET/GCE to uric acid led to the voltammetrie resolution of the overlapping oxidation wave of uric acid and aseorbie acid in a mixture, which allows the simultaneous determination of uric acid and ascorbic acid in a same sample.
出处
《上海师范大学学报（自然科学版）》
2008年第1期74-81,共8页
Journal of Shanghai Normal University(Natural Sciences)
基金
Shanghai Municipal Education Commission(05DZ16).
关键词
2-氨基乙硫醇
尿酸
抗坏血酸
共价修饰
2-aminoethanethiol
uric acid
ascorbic acid
covalent modification
