SYNTHESIS AND OPTIMIZATION OF PERMSELECTIVE POLYMER (POLYINDOLINE) FILM

A polyindoline permselective polymer film was readily synthesized by a n electrochemical polymerization of indoline in an aqueous solution of KCl at a potential of 0.4 V vs Ag/AgCl. The amperometric responses of the polyindoline film-coated platinum electrodes to electroactive (as corbic acid, oxalic acid and hydrogen peroxide) and non-electroactive (lactose, sucrose and urea) substances were measured at a potential of 0.7 V. Effects of various variables such as film thickness, concentra tions of monomer and electrolyte, and pH on the permselective behavior of the polymeric membrane were systematically investigated and the op timal values were determined. It was found that permselective polyindo line-coated electrodes prepared in this one-step procedure permitted h ydrogen peroxide oxidation while it prevented interference due to oxid izable species such as ascorbic acid and oxalic acid. As a result, it is believed that this polymeric membrane, owing to its permselective c haracter, can be used as the protective material in the construction o f hydrogen peroxide-based biosensors.