Ca2+-Switchable Glucose Dehydrogenase Associated with Electrochemical/Electronic Interfaces: Applications to Signal-Controlled Power Production and Biomolecular Release.

An artificial Ca2+-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 Ca2+ cations resulting in reversible enzyme activation. A signal-switchable biofuel cell and biomolecular release have been realized using the Ca2+-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.