Immobilization of heme complex by radiation polymerization

Transparent films containing an iron-porphyrin complex were synthesized by ⁶⁰Co γ-ray irradiation of aqueous solutions of ironporphyrin complex and a water soluble monomer such as 2-hydroxyethylmethacrylate or 1-vinyl-2-pyrrolidone. The iron(II)porphyrin complex was immobilized in the film by covalent bonding without any denaturation, under anaerobic condition or by protection of the ironporphyrin complex with carbon monoxide. After the irradiation of iron(III)porphyrin, the central iron ion was reduced spontaneously to the ferrous state. The films containing the iron(II)porphyrin adsorbed quantitatively carbon monoxide gas.