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

Partially hydrolyzed polyarbutin-containing benzoquinone groups were synthe sized by using chemoenzymatic methods. This polymer was used as a mediator for the oxidation of pyrroloquinoline quinone-dependent glucose dehydrogena se. Polymer was covalently attached to the enzyme through the glucose moiet y of the polymer and amine residues in the protein. Electrochemical studies show that the oxidized benzoquinone attached to the enzyme can act as a me diator for the reoxidation of the enzyme at carbon electrode surfaces. The apparent Michaelis constant and inactivation rate constant of the coupled e nzyme were found to be similar to these parameters of the native enzyme. (C ) 2000 Elsevier Science B.V. All rights reserved.