5,5′-二硫硝基苯甲酸的电化学性质及在谷胱甘肽测定中的应用

Electrochemical properties of 5,5-dithiobis(2-nitrobenzoic acid) and application to the determination of glutathione

利用循环伏安法研究了巯基衍生化试剂5,5′-二硫硝基苯甲酸(DTNB)在玻碳电极上的循环伏安特性.实验发现,DTNB的二硫键在玻碳电极上出现了灵敏的阴极还原电流.通过分析酸度、扫描起始电位、还原型谷胱甘肽(GSH)、扫描次数对DTNB电化学性质的影响,确立了DTNB在电极上各氧化还原峰的归属,并给出了电极的反应机理.根据DTNB二硫键的还原峰电流随GSH浓度的增加其线性降低的特性,建立了伏安法灵敏测定GSH含量的分析方法,该方法的测定结果与常规光度法相吻合.

Electrochemical properties of 5,5-dithiobis（2-nitrobenzoic acid）（DTNB） are investigated using glassy carbon electrode with cyclic voltammetry.Sensitive reductive current is observed by reduction of disufulde bond on the electrode.Influences of acidity,initial potential,reduced glutathioe（GSH）,cycling number on the cyclic voltammograms of DTNB are also investigated and electrochemical mechanism of DTNB on the glassy carbon electrode are proposed accordingly.Linearly decreasing reduction current of disulfide bond of DTNB with the increasing concentration of GSH are observed.According to the linearship between reduction current and GSH concentration,novel electrochemical detection method of GSH are established.The determination results are consistent with those determined by spectrometric method.