Galactose sensor based on galactose oxidase immobilized in polyvinyl formal

A galactose biosensor was developed by immobilizing galactose oxidase in a polyvinyl formal membrane and attached to the oxygen electrode of a dissolved oxygen analyzer for estimation of galactose in milk and milk products. The immobilized enzyme membrane was characterized by atomic force microscopy. The biosensor showed the linearity for 0.5–3.0 g dl−1 galactose. The effects of pH and temperature and the stability of the immobilized galactose oxidase membrane were also studied. The enzyme membrane was found stable at temperatures up to 35 °C and had a shelf life of more than 90 days.