对苯二胺在血红蛋白/聚L-谷氨酸/玻碳修饰电极上的可逆氧化  

Reversible Oxidation of p-Phenylenediamine on Hemoglobin/poly (L-glutamic acid)/Glassy Carbon Modified Electrode

作　　者：李敏[1] 杨昌英[1] 周文凯[1] 朱敏[1] 

机构地区：[1]三峡大学化学与生命科学学院,宜昌443002

出　　处：《应用化学》2010年第9期1093-1098,共6页Chinese Journal of Applied Chemistry

基　　金：湖北省自然科学基金创新群体(2007ABC008);宜昌市科学技术研究(A09302)资助项目

摘　　要：采用电聚合法在玻碳电极(GCE)表面得到导电性能良好的聚L-谷氨酸(PGA)薄膜,通过共价键合法将血红蛋白(Hb)固定于电极表面得到稳定且具有催化活性的Hb/PGA/GCE修饰电极,将其用于对苯二胺(PPD)的可逆氧化。修饰电极交流阻抗及血红蛋白直接电化学实验表明,血红蛋白成功地固定于电极表面,保持良好的电催化活性,能有效催化H2O2的还原。PPD在电极上表现为受吸附控制的准可逆氧化还原反应,Ip,a/Ip,c约为1.02,电极没有明显的钝化现象。氧化还原峰电流与PPD的浓度均呈良好的线性关系,Ip,a(μA)=3.124+0.705cPPD(mmol/L)(r=0.9973)。H2O2的存在使PPD氧化还原峰型更对称,可逆性更好,表明体系中PPD氧化与过氧化酶催化途径一致。A hemoglobin/poly （L-glutamic acid）/glassy carbon electrode （Hb/PGA/GCE） ,targeted for reversible oxidation of p-phenylenediamine（PPD） ,has been fabricated by covalently immobilizing Hb on GCE with a thin layer of conductive pre-electropolymerized PGA.Electrochemical impedance spectra of the electrode confirmed the immobilization of Hb.The resulting modified electrode（Hb/PGA/GCE） gave a redox couple for Hb in PBS buffer and a better electrocatalytic performance to H2O2.This indicated that the direct electron transfer of the active group of the protein could be retained on the electrode surface.The oxidation of PPD was reversible on Hb/PGA/GCE instead of GCE or PGA/GCE.The redox peak current was proportional to the scan rate,and Ip,a/Ip,c about 1.02,indicating a characteristic of quasi-reversible,surface confined electrochemical behavior.Moreover,a new measurement method for PPD in samples was provided since the redox peak currents increased linearly with the concentration of PPD,Ip,a （μA）=3.124＋0.705cPPD （mmol/L） （r=0.9973） .The enzymatic oxidation might be the plausible mechanism because the existence of H2O2 was in favor of the reversible redox of PPD.

关 键 词：血红蛋白 聚L-谷氨酸 对苯二胺 可逆氧化 

分 类 号：O646.5[理学—物理化学]