摘要:
The invention provides a method for quantitative measurement of a substrate with high accuracy by electrochemically oxidizing an electron mediator which has been reduced by enzyme reaction thereby determining the substrate concentration based on a current flowing during electrochemical oxidation from which adverse effects of an easy-to-oxidize substance on the oxidation process have been minimized. The quantitating method in accordance with the present invention comprises a first step for causing a substrate contained in a sample to react with a specific oxidoreductase to the substrate in the presence of an electron mediator in oxidized state, and a second step for electrochemically reducing the electron mediator in oxidized state which remains non-reduced by the enzyme reaction in the first step, thereby obtaining a current flowing during electrochemical reduction.
摘要:
Disclosed is a biosensor facilitating high accuracy quantification of a specific component in a sample solution with no adverse influence of solid substances. The biosensor comprises an electrically insulating base plate, an electrode system comprising a working electrode and a counter electrode formed on the base plate, a reaction layer containing at least one enzyme disposed on the electrode system, and an anionic filter formed on the reaction layer for inhibiting permeation of solid components.
摘要:
A biosensor is disclosed for application to a method for quantitative measurement of a substrate comprising a first step of causing a substrate contained in a sample to react with an oxidoreductase specific to the substrate in the presence of an electron mediator in oxidized state, a second step of applying a potential to a working electrode for reducing the electron mediator in oxidized state that remains not reduced in the first step, and a third step of measuring a reduction current flowing across the working electrode and a counter electrode. The biosensor comprises an electrically insulating base plate, an electrode system having a working electrode and a counter electrode formed on the base plate, and a reaction layer which is formed on or in the vicinity of the electrode system and contains at least an oxidoreductase and an electron mediator, the counter electrode including at least a reductant of a redox compound or an electrolytically oxidizable metal.
摘要:
A biosensor for quantifying a specific compound has a reaction layer containing at least an enzyme, and an electrode system having a working electrode and a counter electrode formed on an insulating base plate; the biosensor detects the specific compound contained in a sample on the basis of an electrochemical response. In quantifying, the working electrode and the counter electrode are short-circuited before the voltage is applied therebetween. The short-circuiting eliminates measuring errors that may occur due to nonuniform dissolution of the reaction layer in a sample, and achieves highly reliable quantification of a specific compound.
摘要:
A cholesterol sensor for quantitative determination of cholesterol is provided containing an electrode system and a reaction reagent system. The electrode system contains a measuring electrode such as a carbon electrode and a counter electrode, and the reaction reagent system contains cholesterol dehydrogenase, nicotinamide adenine dinucleotide and an oxidized electron mediator. Electron mediators include ferricyanide, 1,2-naphthoquinone-4-sulfonate, 2,6-dichlorophenol indophenol, dimethylbenzoquinone, 1-methoxy-5-methylphenazinium sulfate, methylene blue, gallocyanine, thionine, phenazine methosulfate and Meldola's blue. Diaphorase, cholesterol esterase and a surfactant may also be present. The electrode system is on an insulating base plate, and the base plate has a covering member containing a groove that is a sample supplying channel which extends from an end of the base plate to the electrode system. A reaction layer containing the reagent system in dry form and a layer of a hydrophilic polymer is provided on the base plate or the covering member, or on both the electrode system and covering member so as to be exposed to the sample supplying channel. During operation, the electron mediator is reduced in conjunction with oxidation of cholesterol in a sample by cholesterol dehydrogenase, and an amount of current required to electrochemically re-oxidize the electron mediator is directly proportional to a quantity of cholesterol present in the sample.
摘要:
The biosensor of this invention includes an electrically insulating substrate; an electrode system formed on the substrate which includes a working electrode and a counter electrode; and a reaction layer formed on the substrate or above the substrate with a space therebetween. The reaction layer includes a pyranose-oxidizing enzyme.
摘要:
A method using a biosensor is disclosed which facilitates high accuracy quantitation of a substrate by best eliminating adverse effects of red blood cell existing in blood together with the substrate. The biosensor comprises an electrode system including a working electrode and a counter electrode formed on an electrically insulating base plate, and a reaction layer containing at least an oxidoreductase and an electron acceptor, wherein the electron acceptor is a sodium salt.
摘要:
The biosensor of the present invention has a reaction layer that contains at least an oxidoreductase and an electron acceptor and is formed on an electrode system including a working electrode and a counter electrode on a base plate. The working electrode, the counter electrode, and lead conductors connecting with these electrodes are made of carbon. The counter electrode is formed in a substantially C shape, and the working electrode is arranged in a recess of the substantially C-shaped counter electrode. An insulating layer surrounds the counter electrode and the working electrode. A cover member with a groove is combined with the base plate to define a sample supply channel that is formed therebetween and runs toward the electrode system. The groove extends from one end of the base plate and passes over the electrode system, and the insulating layer extends to an air hole formed in a terminal of the groove of the cover member. This arrangement prevents exposure of part of the lead conductor connecting with the working electrode to the sample solution and development of an error in measurement.
摘要:
A biosensor for quantification of a specific component contained in various biological samples comprises an electrically insulating base plate, an electrode system including a working electrode and a counter electrode which are provided on the electrically insulating base plate, a reaction layer formed on the electrode system including at least an oxido-reductase, and an enclosure member having a hollow space constituting a sample supplying channel on the electrically insulating base plate, wherein substantially the whole of the reaction layer is exposed to the hollow space.
摘要:
An apparatus for determining the concentration of a substrate in a sample solution using an electrode system comprising a working electrode, a counter electrode, and a reaction layer which contains at least an oxidoreductase and an electron mediator and is formed on the electrode system to electrochemically measure a reduced amount of the electron mediator resulting from enzyme reaction in the reaction layer, wherein a third electrode is formed as an interfering substance detecting electrode. A current flowing between the counter electrode and the third electrode is measured which is taken as a positive error. Subsequently, voltage application between the counter electrode and the third electrode is released and a voltage for oxidizing the reduced form electron mediator is applied between the working electrode and the counter electrode to measure a current flowing between the two electrodes.