Abstract: A method is provided for measuring a substance using a biosensor, the method comprising: introducing a sample containing the substance into an electrochemical measurement cell which comprises an insulating base plate; at least two electrodes formed on the insulating base plate; and a reagent layer that is disposed on at least one of the electrodes and comprises an oxidoreductase; applying a voltage to the electrodes; detecting a charge transfer limiting current which is generated due to the transfer of electrons from the substance in the sample to the electrode; and determining the concentration of the substance contained in the sample based on the charge transfer limiting current.

Abstract: The present invention provides an enzyme electrode composed of a carbon particle on which glucose dehydrogenase (GDH) with flavine adenine dinucleotide (FAD) as a coenzyme is supported and an electrode layer contacting the carbon particle, wherein the carbon particle and/or the electrode layer are/is composed of the carbon particles with a particle diameter of not more than 100 nm and a specific surface area of at least 200 m2/g.

Abstract: A method is provided for measuring a substance using a biosensor, the method comprising: introducing a sample containing the substance into an electrochemical measurement cell which comprises an insulating base plate; at least two electrodes formed on the insulating base plate; and a reagent layer that is disposed on at least one of the electrodes and comprises an oxidoreductase; applying a voltage to the electrodes; detecting a charge transfer limiting current which is generated due to the transfer of electrons from the substance in the sample to the electrode; and determining the concentration of the substance contained in the sample based on the charge transfer limiting current.

Abstract: An enzyme electrode includes an electrode and a detection layer. The detection layer includes an enzyme, conductive particles, and a non-conductive polymer. The non-conductive polymer is linked to at least one of at least a portion of the enzyme and at least a portion of the conductive particles by a linking chain containing nitrogen or oxygen, and the non-conductive polymer has a region of positive correlation between a concentration of the non-conductive polymer and a response sensitivity of the enzyme electrode.

Abstract: An enzyme electrode includes an electrode, and a detection layer that is in contact with the electrode and includes an oxidoreductase, a water-soluble conductive polymer, and conductive particles, electrons being transferred between the enzyme and the electrode by direct electron transfer in the detection layer.

Abstract: The present invention provides a method for measuring a substrate concentration by accumulating an energy resulting from a reaction between a biocatalyst and a substrate recognized by the biocatalyst to a certain level; and using a dependency of an accumulation rate on the substrate concentration as an index; and a apparatus therefor. In particular, the present invention provides a method in which the measurement of the accumulation rate is carried out by measuring a frequency of an energy release in a certain amount of time when the energy accumulated in the capacitor reaches the certain level and is then released.

Abstract: The present invention provides a method for measuring a substrate concentration by accumulating an energy resulting from a reaction between a biocatalyst and a substrate recognized by the biocatalyst to a certain level; and using a dependency of an accumulation rate on the substrate concentration as an index; and a apparatus therefor. In particular, the present invention provides a method in which the measurement of the accumulation rate is carried out by measuring a frequency of an energy release in a certain amount of time when the energy accumulated in the capacitor reaches the certain level and is then released.

Abstract: The present invention provides a method for measuring a substrate concentration by accumulating an energy resulting from a reaction between a biocatalyst and a substrate recognized by the biocatalyst to a certain level; and using a dependency of an accumulation rate on the substrate concentration as an index; and a apparatus therefor. In particular, the present invention provides a method in which the measurement of the accumulation rate is carried out by measuring a frequency of an energy release in a certain amount of time when the energy accumulated in the capacitor reaches the certain level and is then released.

Abstract: The present invention provides a method for measuring a substrate concentration by accumulating an energy resulting from a reaction between a biocatalyst and a substrate recognized by the biocatalyst to a certain level; and using a dependency of an accumulation rate on the substrate concentration as an index; and a apparatus therefor. In particular, the present invention provides a method in which the measurement of the accumulation rate is carried out by measuring a frequency of an energy release in a certain amount of time when the energy accumulated in the capacitor reaches the certain level and is then released.

Abstract: The present invention provides a method for measuring a substrate concentration by accumulating an energy resulting from a reaction between a biocatalyst and a substrate recognized by the biocatalyst to a certain level; and using a dependency of an accumulation rate on the substrate concentration as an index; and a apparatus therefor. In particular, the present invention provides a method in which the measurement of the accumulation rate is carried out by measuring a frequency of an energy release in a certain amount of time when the energy accumulated in the capacitor reaches the certain level and is then released.

Abstract: A mutant glucose dehydrogenase having an amino acid sequence at least 80% identical to SEQ ID NO:3 and having glucose dehydrogenase activity, wherein amino acid residues corresponding to positions 326, 365 and 472 of said amino acid sequence are replaced with glutamine, tyrosine and tyrosine, respectively, and wherein said mutant glucose dehydrogenase shows an improved substrate specificity to glucose and a reduced reactivity to disaccharides.