Behavior of PQQ glucose dehydrogenase on Prussian blue-modified carbon electrode

Abstract

Glucose sensitive biosensor containing pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase immobilized on Prussian blue (PB)-modified graphite electrode was designed. Properties of the biosensor were investigated in the cathodic and anodic response detection regions. It was shown, that anodic response of the biosensor is sum of two signals: direct electron transport from reduced PQQ to the electrode and by formation of the PQQ-oxygen-PB-carbon ternary complex. Cathodic response of the biosensor is based on the oxidation of the reduced PQQ by PB-oxygen-PB complex. Electrochemical regeneration of the enzyme does not produce free hydrogen peroxide.