Sensor, sensor system, method of manufacturing sensor, and method of measuring concentration of target substance
The present invention provides: a reagent composition having higher storage stability; a sensor involving the reagent composition; and others. According to the present invention, a specific heterocyclic compound is added to a reagent composition to improve the storage stability of the reagent composition and reduce the degree of fluctuation in current values in a sensor that utilizes reagent composition.
1. A sensor comprising:
a sample chamber having an opening configured to receive therein a liquid sample;
at least one pair of electrodes disposed in the sample chamber; and
a reagent layer being disposed in the sample chamber,
wherein the reagent layer comprises:
an oxidoreductase;
an electron acceptor; and
a heterocyclic compound represented by one of the following general formulae (I-1) to (I-5):
wherein:
R 1 represents a hydrogen atom;
R 2 to R 5 , if present, each independently represent a hydrogen atom, an amino group, a hydroxyl group, or a C 1-12 hydrocarbon group;
the C 1-12 hydrocarbon group may have at least one substituent selected from the group consisting of an amino group, a hydroxyl group, and a carboxyl group;
at least one of R 2 to R 5 of the heterocyclic compound is an amino group; and
the heterocyclic compound is not histidine or histamine.
2. The sensor according to claim 1 , wherein the heterocyclic compound has five nitrogen atoms.
3. The sensor according to claim 1 , wherein the heterocylic compound is at least one compound selected from the group consisting of 2-amino-imidazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, and 3,5-diamino-1,2,4-triazole.
4. The sensor according to claim 1 , wherein the reagent layer contains glucose dehydrogenase as the oxidoreductase.
5. The sensor according to claim 4 , further comprises a coenzyme operable with the oxidoreductase.
6. The sensor according to claim 5 , wherein the oxidoreductase has pyrroloquinoline quinone (PQQ) dependency or flavin adenine dinucleotide (FAD) dependency.
7. The sensor according to claim 1 , wherein the reagent layer is solid.
8. The sensor according to claim 1 , wherein the reagent layer is disposed so as to be in contact with both electrodes of the at least one pair of electrodes.
9. A sensor system comprising:
the sensor according to claim 1 ;
a measurement section that measures a current value between electrodes of the at least one pair of electrodes; and
a calculation section that calculates a concentration of a target substance in the liquid sample based on a measurement result obtained by the measurement section.
10. A sensor comprising:
a sample chamber having an opening configured to receive therein a liquid sample;
at least one pair of electrodes disposed in the sample chamber; and
a reagent layer being disposed in the sample chamber,
wherein the reagent layer comprises:
an oxidoreductase;
an electron acceptor; and
a heterocyclic compound,
wherein the heterocyclic compound is at least one compound selected from the group consisting of 2-amino-imidazole, 4,5-bis(hydroxymethyl)imidazole, 2-methylimidazole, 1,2-dimethylimidazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, and 3,5-diamino-1,2,4-triazole.
11. A method of manufacturing a sensor, comprising:
(a) providing at least one pair of electrodes on a substrate;
(b) applying on the substrate a reagent composition; and
(c) drying the reagent composition applied in the step (b) to form a reagent layer,
wherein the reagent layer comprises:
an oxidoreductase;
an electron acceptor; and
a heterocyclic compound represented by one of the following general formulae (I-1) to (I-5):
wherein:
R 1 represents a hydrogen atom;
R 2 to R 5 , if present, each independently represent a hydrogen atom, an amino group, a hydroxyl group, or a C 1-12 hydrocarbon group;
the C 1-12 hydrocarbon group may have at least one substituent selected from the group consisting of an amino group, a hydroxyl group, and a carboxyl group;
at least one of R 2 to R 5 of the heterocyclic compound is an amino group; and
the heterocyclic compound is not histidine or histamine.
12. A method of measuring a concentration of a target substance, comprising:
(a) bringing a reagent composition into contact with a liquid sample;
(b) detecting a current generated in the step (a); and
(c) measuring the concentration of the target substance based on a detection result obtained in the step (b),
wherein the reagent composition comprises:
an oxidoreductase;
an electron acceptor; and
a heterocyclic compound represented by one of the following general formulae (I-1) to (I-5):
wherein:
R 1 represents a hydrogen atom;
R 2 to R 5 , if present, each independently represent a hydrogen atom, an amino group, a hydroxyl group, or a C 1-12 hydrocarbon group;
the C 1-12 hydrocarbon group may have at least one substituent selected from the group consisting of an amino group, a hydroxyl group, and a carboxyl group;
at least one of R 2 to R 5 of the heterocyclic compound is an amino group; and
the heterocyclic compound is not histidine or histamine.