Reagentless biosensor based on PQQ-depended glucose dehydrogenase and partially hydrolyzed polyarbutin

Partially hydrolyzed polyarbutin-containing benzoquinone groups were synthesized by using chemoenzymatic methods. This polymer was used as a mediator for the oxidation of pyrroloquinoline quinone-dependent glucose dehydrogenase. Polymer was covalently attached to the enzyme through the glucose moiety of the polymer and amine residues in the protein. Electrochemical studies show that the oxidized benzoquinone attached to the enzyme can act as a mediator for the reoxidation of the enzyme at carbon electrode surfaces. The apparent Michaelis constant and inactivation rate constant of the coupled enzyme were found to be similar to these parameters of the native enzyme.