title: Coulometric D-fructose biosensor based on direct electron transfer using D-fructose dehydrogenase.
abstract: This paper describes a batch-type coulometric d-fructose biosensor based on direct electron transfer reaction of d-fructose dehydrogenase (FDH) adsorbed on a porous carbon electrode surface. The adsorbed-FDH electrodes catalyzed the electrochemical two-electron oxidation of d-fructose to 5-keto-d-fructose without a mediator. Nanostructured carbon particle-modified electrodes were used for the coulometric d-fructose biosensor to enhance the catalytic current density. The electric charge for the d-fructose oxidation gained by the biocoulometric measurement was in good agreement with the theoretical value corresponding to d-fructose amount in the range from 1 to 100 mM with a sample volume of 1 muL. This method is also applicable to the determination of several oligo/polysaccharides containing the d-fructose unit, in combination with specific hydrolases to yield d-fructose. An example was demonstrated by sucrose determination in which the electrode modified with FDH and invertase was used as a working electrode. To address the problem of electroactive interferences such as ascorbate, the electric charge at the FDH-free electrode was subtracted from the total charge obtained at the FDH-adsorbed electrode. The d-fructose concentrations in several beverages were successfully determined with this method.
authors.affiliation: Division of Applied Life Science, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan. seiya@kais.kyoto-u.ac.jp
authors.forename: Seiya
authors.initials: S
authors.lastname: Tsujimura
authors.forename: Akiko
authors.initials: A
authors.lastname: Nishina
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kamitaka
authors.forename: Kenji
authors.initials: K
authors.lastname: Kano
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D005632:Fructose / Q000031:analogs & derivatives / Q000032:analysis* / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism*
chemical_list: C033856:5-ketofructose; D005632:Fructose; D010088:Oxidoreductases