A galactose biosensor was developed by immobilizing galactose oxidase (GAox) on poly (glycidyl methacrylate-co-vinylferrocene) (poly (GMA-co-VFc)) film. The enzyme was immobilized via amine group onto polymeric mediator. The biosensor was characterized by the specific activity of the immobilized galactose oxidase, the apparent Michaelis constant K(M)(app), and the stability expressed by time and a number of the performed analysis. The optimized galactose biosensor exhibited a linear response range from 2 to 20 M and detection limit of 0.1 mM toward galactose. The response time of the biosensor was 5 s. The effects of the pH and the temperature of the immobilized galactose oxidase electrode were also studied. (C) 2010 Elsevier B.V. All rights reserved.