PYRROLOQUINOLINEQUINONE ENZYME ELECTRODE BASED ON THE COUPLING OF METHANOL DEHYDROGENASE TO A TETRATHIAFULVALENE TETRACYANOQUINODIMETHANE ELECTRODE

An enzyme electrode based on the coupling of a PQQ-containing methanol dehydrogenase (EC 1.1.99.8) and the novel electrode material, TTF-TCNQ, is reported. Characterization of this enzyme electrode shows that the substrate-reduced enzyme is rapidly turned over by this electrode material, whereas no turnover is evident on a conventional (i.e., Pt) electrode. Oxidation of the reduced form of the enzyme at organic conducting salt electrodes is effected in the absence of ammonium ion activators unlike the situation in homogeneous solution, implying that a novel electron-transfer mechanism occurs with these electrodes. Enzyme properties (K(m), T sensitivity, pH dependence) when interfaced to the electrode are reported, and the response characteristics of the resulting biosensor are summarized.