Novel FAD-Dependent Glucose Dehydrogenase for a Dioxygen-Insensitive Glucose Biosensor
A novel FAD-dependent glucose dehydrogenase (FAD-GDH) was found and its enzymatic property for glucose sensing was characterized. FAD-GDH oxidized glucose in the presence of some artificial electron acceptors, except for O<SUB>2</SUB>, and exhibited thermostability, high substrate specificity and a large Michaelis constant for glucose. FAD-GDH was applied to an amperometric glucose sensor with Fe(CN)<SUB>6</SUB><SUP>3−</SUP> as a soluble mediator. The use of a relatively high concentration of Fe(CN)<SUB>6</SUB><SUP>3−</SUP> resulted in a good linearity between the current response and the glucose concentration, taking into account a large Michaelis constant for Fe(CN)<SUB>6</SUB><SUP>3−</SUP>. The glucose sensor was completely insensitive to O<SUB>2</SUB> and responded linearly to glucose up to 30 m<small>M</small>. Compared to glucose, the response to other saccharides was negligible. The sensor can be stored at room temperature in a desiccator for at least one month without any change in the response or activity.
- Bioscience, biotechnology, and biochemistry
Bioscience, biotechnology, and biochemistry 70(3), 654-659, 2006-03-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry