Amperometric Biosensor with “Liquid” Enzyme Membrane

ABSTRACTThe advantages of the “liquid” membranes for biosensors with enzyme, covalently bound to soluble dextran, are discussed in this article. A three layer steady state model is used to compare biosensors with homogeneous (liquid) and nonhomogeneous enzyme membranes with respect to their technical characteristics: sensitivity and response time. Theoretical analysis shows that the “liquid” membrane sensor is by 10% more sensitive and by 20% -120 % faster than the one with a nonhomogeneous enzyme membrane. The experiments were made with a new prototype of oxygen sensor, more suitable to fix an uniform enzyme (glucose oxydase + catalase) layer to the fronthead. The experimental results confirm the theoretical conclusions.