DIRECT ELECTROCHEMISTRY OF CYTOCHROME-C A T A MICROBAND GOLD ELECTRODE MODIFIED WITH 4,6-DIMETHYL-2-MERCAPTOPYRIMIDINE

The direct electrochemistry of cytochrome c at microband gold electrod e modified with a new promoter 4,6-dimethyl-2-mercaptopyrimidine was i nvestigated. The self-assembly monolayer of 4, 6-dimethyl-2-mercaptopy rimidine on the surface of gold electrode was characterized by IR spec trum and XPS. Cyclic voltammetric experiments indicated that the elect rochemistry of cytochrome c at gold electrode modified with this promo ter was quasi-reversible with one-electron transfer reaction. The hete rogeneous electron-transfer rate constant, k(s), of cytochrome c was e valuated to be ca.6.6x 10(-3)cm/s. The effects of the immersion time a nd the oxygen in air on the promoter to promote the direct electrochem istry of cytochrome c were discussed.