Fabrication of covalently attached multilayer film electrode containing iron porphyrin and its electrocatalysis toward sulfite

Construction of a highly stable covalently attached multilayer film electrode containing iron porphyrin was achieved by UV irradiation of ionic self-assembled multilayer films of diazo-resins (DAR) and anionic Fe(III)tetrakis(psulfonatophenyl)porphyrin (FeTSPP). The multilayer films had been characterized by UV, IR spectra and cyclic valtammetry. The electrocatalytic transformation of sulfite to SO42- by the multilayer film electrode containing FeTSPP was investigated. In 0.1 M NH4OH-NH4Cl buffer solution (pH 8.74) and 0.1 M borate buffer solution (pH 9.18) the electrocatalytic oxidation of sulfite through the multilayer film electrode can be performed. However, in acetate buffer solution (pH 4.0) the electrocatalytic reduction of sulfite by the multilayer film electrode had also good activity. The modified electrode also exhibited a fast response and good stability.