New Enzyme Membrane for Enzyme Electrodes

A new method for the preparation of thin, uniform, self-mounted enzyme membranes, directly coating the surface of glass pH electrodes, was developed. The enzyme is dissolved in a solution containing synthetic prepolymers. The electrode is dipped in the solution, dried, and drained carefully. The backbone polymer is then cross-linked under controlled conditions to generate a thin (~50-μm) enzyme membrane. The method was demonstrated and characterized by the determination of acetylcholine by an acetylcholine esterase electrode, urea by urease electrode, and penicillin G by penicillinase electrode. Linear response in a wide range of substrate concentrations and high storage and operational stability were recorded for all the enzymes tested.