Glycerol biosensor based on glycerol dehydrogenase incorporated into polyaniline modified aluminum electrode using hexacyanoferrate as mediator

Enzyme-modified electrodes were fabricated by the immobilization of glycerol dehyrogenase into the polyaniline film and were used as glycerol biosensors. Two different electrodes were prepared by forming monolayer and bilayer electroactive films on the electrode surface and were compared. Potassium ferrocyanide was used as mediator of the biosensing reaction. The biosensors exhibit amperometric response to the glycerol in the range 5×10−6 to 2×10−3 M with detection limit of 1×10−6 M. The Michaelis–Menten constants, Km′, of the electrodes were calculated, their values indicates that the enzyme has not chemically modified with the electrode materials and has its original enzymatic activity. The electrode has a good stability and selectivity due to the enhanced stability of the deposited polyaniline film on Al substrate.