Pyruvate sensor based on pyruvate oxidase immobilized in a poly(mercapto-p-benzoquinone) film

Pyruvate oxidase was immobilized in a conductive redox polymer, poly(mercapto-p-benzoquinone) prepared on an Au-electroplated glassy carbon electrode. The immobilization of the enzyme was carried out by an electropolymerization of mercaptohydroquinone in the presence of the enzyme. The enzyme could be immobilized in the polymer without loss of its native specificity. The enzyme electrode functioned well as a direct response type of sensor, where the polymer chain served as a conductive molecular chain between the active centers in the enzyme and the substrate electrode. The enzyme electrode responded to pyruvate over a wide concentration range of 1 mu M to 2 mM. The response current was scarcely affected by dissolved oxygen. Response characteristics as well as kinetic parameters have been evaluated. (C) 1999 Elsevier Science S.A. All rights reserved.