血红蛋白在纳米羟基磷灰石修饰的热解石墨电极上的直接电化学  

Direct electrochemisty immobilized of hemoglobin at hydroxyapatite modified by edge-plane pyrolytic graphite graphite electrode

作　　者：高玉莲[1] 田燕妮[1] 

机构地区：[1]山西大学分子科学研究所化学生物学与分子工程教育部重点实验室

出　　处：《化学研究与应用》2007年第6期589-593,共5页Chemical Research and Application

基　　金：山西省回国留学基金资助;山西省自然科学基金(2006011016)资助

摘　　要：采用超声辅助沉淀法合成羟基磷灰石纳米晶体，制作了以纳米羟基磷灰石（HAp）修饰的热解石墨电极（EPC）。并研究了血红蛋白在该修饰电极上的直接电化学行为。在pH6．9的磷酸盐（PBS）缓冲溶液中，得到一对可逆的血红蛋白辅基血红素Fe（Ⅲ）／Fe（Ⅱ）电对的循环伏安氧化还原特征峰，式量电位E^0＇ p=-0．356V（vs．SCE，pH6．9），几乎不随扫速的改变而变化，电子转移数为1．041，近似一个辅基发生一个电子转移。Hb在HAp／EPG电极表面直接电子转移的速率常数为0．6074。在该纳米HAp微环境中，Hb与EPG电极之间的电子传递得到极大促进，并显示了较好的稳定性。式量电势pH3．6—9．0范围内与溶液的pH成线性关系，直线斜率为-56．0mV／pH，说明Hb的电子传递过程伴随质子的转移。探讨了Hb—HAp修饰电极对H2O^2的电催经性质，为制作生物传感器打下基础。The nano-scale hydroxyapatite （HAp） was prepared with the precipitation method. An edge-plane pyrolytic graphite electrode modifide by HAp and its application to the electro-chemical determination of hemoglobin （Hb） was studied. Hb-HAp/EPG modified electrodes appeared a pair of well-defined and nearly reversible cychc vohammetric peaks for HbFe（ Ⅲ）/Fe（Ⅱ ） redox couple at about-0. 356V （ vs, SCE） in pH 6. 9 phosphate buffers, which was almost independent of the scan rate. The number of electron transferrde is 1. 041 ,the average apparent heterogeneous electron transfer rate constant （ks） obtained by fitting CV data for Hb on HAp-modifide electrode is 0. 6074s^-1. The formal potential of Hb hemeFe（ Ⅲ ）/Fe（Ⅱ ） couple shifted linearly between pH 3. 6- 9. 0 with the slope value of-56 mV/pH,suggesting that one proton was coupled to each electron transfer in the electrochemical reaction. It was demonstrated by SEM that the structure of Hb was still maintained native-hke in the film. The electron transfer rate between Hb and PG electrldes was gready facihtated in microenvironment of HAp films, showing beter stability. The immobilized Hb displayed the features of a peroxidase and gave an excellent electroeatalytic response to the reduction of H2O2. This work provides a possible route of using Hb-HAp/EPG modified electrodes as the biosensors.

关 键 词：血红蛋白 纳米羟基磷灰石 热解石墨电极 直接电化学 

分 类 号：O646.54[理学—物理化学]