Immobilization of invertase in conducting copolymer matrices of 3-methylthienyl methacrylate with pyrrole and thiophene was achieved by constant potential electrolysis using sodium dodecyl sulfate (SDS) as the supporting electrolyte. Polythiophene (PTh) was also used in entrapment process for comparison. Kinetic parameters, Michaelis-Menten constant, K-m, and the maximum reaction rate, V-max, were investigated. Operational stability and temperature optimization of the enzyme electrodes were also examined. (C) 2002 Elsevier Science B.V. All rights reserved.