Voltammetric behavior of cysteine and metallothionein on cobalt( II ) tetrasulfonated phthalocyanine modified glassy carbon electrodes

Cysteine, and rat Cd, Zn‐metallothionein (Cd, Zn‐MT) have been studied electrochemically at glassy carbon electrodes modified with cobalt(II) tetrasulfonated phthalocyanine, [CoIITSPc]4−, where Pc(2‐) = phthalocyanine dianion. The electrode was modified by electrodeposition of [CoIITSPc]4−. The anodic currents for the oxidation of cysteine on these electrodes are observed at 0.82 V (vs. Ag/AgCl) in acidic media. The anodic currents for the oxidation of Cd, Zn‐MT are observed at 0.90 V at pH 8.4 (Tris buffer).