VOLTAMMETRIC STUDIES OF SPINACH FERREDOXIN ON A GLASSY-CARBON ELECTRODE MODIFIED WITH COBALT(II) TETRASULFOPHTHALOCYANINE

Spinach ferredoxin has been studied electrochemically at a glassy carb on electrode (GCE) modified with cobalt(II) tetrasulfophthalocyanine ( [Co(II)TSPc](4-)). Anodic peak currents due to the oxidation of the cy steine component of ferredoxin were observed at 0.90 V (vs. Ag/AgCl) ( pH 7.4, HEPES buffer). The magnitudes of the peak currents were depend ent on pH. Catalytic oxidation of the cysteine component of ferredoxin were observed at 0.90 V (vs. Ag/AgCl) GCE was modified with cobalt(II ) and oxomolybdenum(V) phthalocyanine [CoPe and OMo(OH)Pc, respectivel y], and with copper(II) tetrasulfophtalocyanine complexes ([Cu(II)TSPc ](4-)).