The heterogeneous electron transfer reaction of heme proteins including Hb, myoglobin and cytochrome c at a Pt mesh electrode with adsorbed methylene blue has been investigated. The thin-layer spectroelectrochem. technique was used for observing the electron transfer processes of these three proteins, and the corresponding electrode rate constants were measured.

Key words: HUMAN, CYTOCHROME, HEMOGLOBIN, CATTLE, EQUINE, CHEMICAL MODIFIED ELECTRODE, BIOELECTROCHEMISTRY, METHYLENUM CAERULEUM, NON-HOMOGENEOUS, MYOGLOBIN