Ca-Switchable Glucose Dehydrogenase Associated with Electrochemical/Electronic Interfaces: Applications to Signal-Controlled Power Production and Biomolecular Release.

An artificial Ca-regulated PQQ glucose dehydrogenase (PQQ-GDH) enzyme was electrically connected to conducting electrodes and semiconductor interfaces. Direct electron transfer from the enzyme to the conducting electrode support was stimulated by the addition of Ca cations resulting in reversible enzyme activation. A signal-switchable biofuel cell and biomolecular release have been realized using the Ca-activated enzyme immobilized on conducting electrodes. Interfacing the signal-switchable enzyme with a semiconductor chip allowed electronic read out of the enzyme ON-OFF states. The developed approach based on the signal-regulated PQQ-GDH enables numerous bioelectrochemical/bioelectronic applications of the developed systems in signal-activated biosensors and biofuel cells, as well as in biomolecular computing/logic systems.