INVESTIGADORES
FLEXER Victoria
artículos
Título:
Wired Pyrroloquinoline Quinone Soluble Glucose Dehydrogenase Enzyme Electrodes Operating at Unprecedented Low Redox Potential
Autor/es:
VICTORIA FLEXER; NICOLAS MANO
Revista:
ANALYTICAL CHEMISTRY
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2014 vol. 86 p. 2465 - 2473
ISSN:
0003-2700
Resumen:
We report unprecedented high current densities for the enzymatic oxidation of glucose already at 0 V versus Ag/AgCl. The modified electrodes were made by assembling pyrroloquinoline quinone (PQQ)-soluble glucose dehydrogenase (PQQ-sGDH) from Acinetobacter calcoaceticus with osmium-based redox polymers and a cross-linker. Both redox mediators are made of a poly(4-vinylpyridine) (PVP) polymer with Os complexes tethered to the polymer backbone via long C chains, giving the Os complexes flexibility and mobility inside the redox hydrogels. Current densities larger than 1 mA cm?2 were measured already below 0 V with a plateau value of 4.4 mA cm?2. Similar hydrogel electrodes comprising the same redox polymers and glucose oxidase (GOx) showed less than half the current densities of the PQQ-sGDH electrodes. The current versus potential curve dependence showed a sigmoidal shape characteristic of mediated enzyme catalysis but with a current increase versus potential less sharp than expected. Surprisingly, the midwave redox potential was positively shifted with respect to the potential of the redox mediator.