Electrochemical study of the interaction between cytochrome c and DNA at a modified gold electrode.
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.
Ding
XiaoQin
X
Department of Chemistry, Beijing Normal University, Beijing 100875, China.
Li
Jinhua
J
Hu
Jingbo
J
Li
Qilong
Q
D000818:Animals; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004563:Electrochemistry; D004566:Electrodes; D005399:Fishes; D006046:Gold / Q000737:chemistry*; D006321:Heart / Q000502:physiology; D006736:Horses; D008297:Male; D018625:Microscopy, Atomic Force; D013094:Spermatozoa / Q000737:chemistry
D006046:Gold; D045304:Cytochromes c; D004247:DNA