Exceptionally high glucose current on a hierarchically structured porous carbon electrode with "wired" flavin adenine dinucleotide-dependent glucose dehydrogenase.
J Am Chem Soc
; 136(41): 14432-7, 2014 Oct 15.
Article
em En
| MEDLINE
| ID: mdl-25244161
ABSTRACT
This article introduces a carbon electrode designed to achieve efficient enzymatic electrolysis by exploiting a hierarchical pore structure based on macropores for efficient mass transfer and mesopores for high enzyme loading. Magnesium oxide-templated mesoporous carbon (MgOC, mean pore diameter 38 nm) was used to increase the effective specific surface area for enzyme immobilization. MgOC particles were deposited on a current collector by an electrophoretic deposition method to generate micrometer-scale macropores to improve the mass transfer of glucose and electrolyte (buffer) ions. To create a glucose bioanode, the porous-carbon-modified electrode was further coated with a biocatalytic hydrogel composed of a conductive redox polymer, deglycosylated flavin adenine dinucleotide-dependent glucose dehydrogenase (d-FAD-GDH), and a cross-linker. Carbohydrate chains on the peripheral surfaces of the FAD-GDH molecules were removed by periodate oxidation before cross-linking. The current density for the oxidation of glucose was 100 mA cm(-2) at 25 °C and pH 7, with a hydrogel loading of 1.0 mg cm(-2). For the same hydrogel composition and loading, the current density on the MgOC-modified electrode was more than 30 times higher than that on a flat carbon electrode. On increasing the solution temperature to 45 °C, the catalytic current increased to 300 mA cm(-2), with a hydrogel loading of 1.6 mg cm(-2). Furthermore, the stability of the hydrogel electrode was improved by using the mesoporous carbon materials; more than 95% of the initial catalytic current remained after a 220-day storage test in 4 °C phosphate buffer, and 80% was observed after 7 days of continuous operation at 25 °C.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carbono
/
Glucose 1-Desidrogenase
/
Flavina-Adenina Dinucleotídeo
/
Glucose
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Japão