细胞色素c在Eastman AQ聚离子薄膜电极上的直接电化学  

DIRECT ELECTROCHEMISTRY OF CYTOCHROME C AT EASTMAN AQ IONOMER FILM ELECTRODES

作　　者：陈小乐[1] 胡乃非[1] 曾泳淮[1] 

机构地区：[1]北京师范大学化学系,北京100875

出　　处：《北京师范大学学报（自然科学版）》2002年第4期515-520,共6页Journal of Beijing Normal University(Natural Science)

基　　金：国家自然科学基金资助项目 (2 99750 0 3)

摘　　要：将聚磺酸酯EastmanAQ38(AQ)与细胞色素c (Cytc)的混合水分散系涂布于热解石墨电极表面 ,晾干后可形成Cytc AQ薄膜 .在pH 7.6的缓冲溶液中 ,Cytc AQ薄膜电极表现出良好的直接电化学行为 ,电化学活性中心为血红素Fe(Ⅲ ) /血红素Fe(Ⅱ )氧化还原对 .Cytc AQ薄膜在 - 0 .0 5V(vsSCE)处的一对可逆的循环伏安还原氧化峰随浸泡时间的延长而逐渐降低 ,而在 - 0 .4 0V的另一对峰逐渐增高 ,表明Cytc在AQ薄膜中很可能经历了由其原始构象向另一种新构象的转变 ,后者在AQ薄膜中十分稳定 .对其伏安行为进行了较详尽的研究 ,并估计了体系的电化学参数 ,如表观异相电子传递速率常数ks和式量电位E°′等 .CytcA mixture of an aqueous dispersion of poly (ester sulfonic acid) or Eastman AQ38 (AQ) and a solution of cytochrome c (Cyt c) is cast on the surface of pyrolytic graphite (PG) electrodes, and Cyt c AQ films are formed after being dried. In pH 7.6 buffers,Cyt c AQ film electrodes demonstrate good direct electrochemistry.The electroactive center of Cyt c in AQ films is the heme Fe(Ⅲ)/Fe(Ⅱ) redox couple. For Cyt c AQ films, the first pair of cyclic voltammetric peaks at -0.05 V(vs SCE) decreases gradually with soaking time while the second peak pair at -0.40 V increases at the same time, indicating possible transformation of Cyt c from its native conformation to a new one. The new conformation in Cyt c AQ films is quite stable in solutions, and its voltammetric behavior is studied in detail. The electrochemical parameters of the system, such as the apparent heterogeneous electron transfer rate constant ( k s) and formal potential ( E °′), are estimated. Cyt c AQ films can catalyze the reduction of oxygen in solutions.

关 键 词：细胞色素C EastmanAQ 聚离子薄膜电极 直接电化学 电化学催化 聚磺酸酯 电化学活性 Cytc-AQ薄膜电极 

分 类 号：Q26[生物学—细胞生物学] O657.1[理学—分析化学]