Direct Electrochemistry of Cytochrome c on EDTA-ZrO_2 Organic-inorganic Hybrid Film Modified Electrodes

摘要

A composite film of ethylenediamine tetraacetic acid (EDTA)-ZrO_2 organic-inorganic hybrid was prepared based on the chelation between Zr(IV) and EDTA. The direct electrochemical behavior of cytochrome c (cyt. c) at the hybrid film modified glassy carbon electrodes was investigated. The immobilized EDTA can promote the redox of heme in horse heart cyt. c which gives rise to a pair of reversible redox peaks with a formal potential of 40 mV (vs. SCE). The peak current increased linearly with the increase of cyt. c concentration in the range of 1.6 X 10~(-6)— 8.0X 10~(-5) mol·L~(-1) with the correlation coefficient of 0.996. Further investigation shows that metal ions can impede the electron transfer of cyt. c. The impediment capability of metal ions depends on their coordination capability with EDTA and their valence number.