A quantitation method of ethanolamine phosphate capable of measuring trace amounts of ethanolamine phosphate, or oxidoreductase used for the quantitation method thereof, a quantitation composition, a quantitation kit, a sensor chip, or a sensor is provided. According to an embodiment of the present invention, a quantitation method of ethanolamine phosphate including allowing phosphatase to act on a sample to convert ethanolamine phosphate contained in the sample into ethanolamine, and allowing oxidoreductase to act on the ethanolamine is provided.

Provided are an amadoriase that is less likely to be influenced by oxygen concentration and a method and a reagent kit for measurement of HbA1c using such amadoriase. Provided are an amadoriase that is obtained via substitution of one or more amino acid residues at a position or positions corresponding to the position(s) selected from the group consisting of positions 280, 267, 269, 54, and 241 of the amadoriase derived from the genus Coniochaeta, a method for measurement of HbA1c, a reagent kit for measurement, and a sensor using such amadoriase. The modified amadoriase according to the invention has a lowered oxidase activity and an enhanced dehydrogenase activity, and this enables the use of an electron mediator, and this reduces the influence of oxygen concentration. Thus, HbA1c can be measured with high sensitivity.

Apparatus and methods for determining the blood glucose concentration of a patient are disclosed A saliva glucose measurement strip is used in conjunction with a glucose measurement device to measure an electrochemical signal of a saliva sample and the measured electrochemical signal is correlated to a blood glucose convention.

A reagent for detecting an analyte comprises a flavoprotein enzyme, a mediator such as a phenothiazine mediator, at least one surfactant, a polymer and a buffer. The reagent may be used with an electrochemical test sensor that includes a plurality of electrodes.

The present disclosure relates to an electron transfer mediator comprising the osmium complex or a salt thereof, a reagent composition for an electrochemical biosensor, and an electrochemical biosensor, where the osmium compound or its salt maintains a stable oxidation-reduction form for an extended time period, a capacity to react with oxidoreductase being capable of performing the redox reaction of the target analytes, and no effect of oxygen partial pressure.

A method of depositing reagent on an electrochemical test sensor adapted to determine information relating to an analyte includes providing a base and forming an electrode pattern on the base. The method further includes depositing the reagent on at least the electrode pattern using a reagent-dispensing system. The reagent-dispensing system applies mechanical force to the reagent in the reagent-dispensing system to assist in providing a wet reagent droplet on at least the electrode pattern.

NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

A method of making an electrochemical sensor strip that includes: depositing a first electrode on a base; depositing a second electrode on the base; applying a first layer onto the first electrode; and applying a second layer onto the second electrode. The first layer includes an oxidoreductase and a mediator. The second layer includes a soluble redox species.

A system for the electrochemical detection of creatinine levels includes a test strip including an electrode and a counter electrode, the electrode and counter electrode located proximate to a sample reception area; and a coating on one of the electrode and counter electrode, the coating including a reagent coating for creatinine.

In one embodiment, a working electrode measuring the presence of a first analyte is disclosed. The working electrode includes a working conductor that has a first electrode reactive surface. The working electrode further includes a first transport material that enables flux of the first analyte to the first reactive chemistry. Additionally, a first reactive chemistry that is responsive to the first analyte is included in the working electrode. The first reactive chemistry includes a mediator, an enzyme and a cofactor. Wherein the first reactive chemistry is located between the working conductor and the first transport material.