Effect of milk proteins on the behavior of a biosensor based on poly(allylamine) containing an osmium complex wired to redox enzymes - Part 2. Bienzymatic configuration

Four configurations of an enzyme electrode to assess lactate concentration in dairy products are studied. In these bienzymatic multilayer systems, the inner layer was constructed by crosslinking peroxidase with poly(allylamin e) containing an osmium complex (OsPAA), and an outer layer containing lact ate oxidase (LOx) immobilized in polymeric matrices. When the hydrogen pero xide formed by the LOx layer reaches the inner layer, the electronic flow b etween the wired peroxidase and the electrode surface produces a cathodic c urrent, proportional to lactate concentration. Parameters such as the effec t of ionic strength, stability when the electrode is used as detector in a FIA system and reproducibility were examined. This arrangement allows worki ng in undiluted milk samples. (C) 2001 Elsevier Science B.V. All rights res erved.