Ding XiaoQin, Li Jinhua, Hu Jingbo, Li Qilong
Department of Chemistry, Beijing Normal University, Beijing 100875, China.
Anal Biochem. 2005 Apr 1;339(1):46-53. doi: 10.1016/j.ab.2004.11.021.
The direct electron transfer of surface-confined horse heart cytochrome c (Cyt c) was achieved using COOH-terminated alkanethiolate-modified gold electrode. Later DNA was immobilized on the two-layer modified electrode. The quantitative determination of DNA was explored and the interaction between cytochrome c and DNA was studied. The binding site sizes were determined to be 15 bp per Cyt c molecule with double-stranded (ds) DNA and 30 nucleotides binding one Cyt c molecule with single-stranded (ss) DNA. At the dsDNA/Cyt c/MUA/Au electrode, the rate constant of oxidation electron transfer k(s,ox)=1.59x10(-3)cms-1 was obtained, at the ssDNA/Cyt c/MUA/Au electrode, the value was 2.43x10(-3)ms-1 when the scan rate was 1.0V/s. The different electrodes were characterized with electrochemical quartz crystal microbalance and atomic force microscope.
使用羧基末端烷硫醇盐修饰的金电极实现了表面受限马心细胞色素c（Cyt c）的直接电子转移。随后将DNA固定在双层修饰电极上。探索了DNA的定量测定，并研究了细胞色素c与DNA之间的相互作用。确定结合位点大小为每个细胞色素c分子与双链（ds）DNA结合15个碱基对，与单链（ss）DNA结合一个细胞色素c分子的30个核苷酸。在dsDNA/Cyt c/MUA/Au电极上，当扫描速率为1.0V/s时，氧化电子转移速率常数k(s,ox)=1.59x10(-3)cms-1，在ssDNA/Cyt c/MUA/Au电极上，该值为2.43x10(-3)ms-1。用电化学石英晶体微天平（EQCM）和原子力显微镜（AFM）对不同电极进行了表征。
