Biosensor, and a method and a device for quantifying a substrate in a sample liquid using the same

Claim 3

A method for quantifying a substrate according to claim 1, wherein the step of applying a voltage between the counter electrode and both of the third electrode and the counter electrode is conducted while a voltage is continuously applied between the counter electrode and the third electrode.

Claim 6

A method for quantifying a substrate according to claim 3, wherein the step of applying a voltage between the working electrode and the counter electrode is conducted while a voltage is continuously applied between the counter electrode and the third electrode.

Claim 7

A quantifying device for a substrate contained in a sample liquid comprising: a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises: means for detecting an electrical change between the counter electrode and the third electrode caused by supplying a sample liquid to the reaction layer; means for applying a voltage between the working electrode and both of the third electrode and the counter electrode after detecting the electrical change; and means for measuring a current flowing between the working electrode and the counter electrode.

Claim 8

A quantifying device for a substrate contained in a sample liquid comprising: a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises: means for detecting an electrical change between the counter electrode and the third electrode caused by supplying a sample liquid to the reaction layer; means for applying a voltage between the working electrode and both of the third electrode and the counter electrode after detecting the electrical change; and means for measuring a current flowing between the working electrode and the counter electrode.

Claim 9

A quantifying device according to claim 5, wherein the means for applying a voltage between the working electrode and both of the third electrode and the counter electrode applies the voltage while a voltage is continuously applied between the counter electrode and the third electrode.

Claim 10

A quantifying device for a substrate contained in a sample liquid comprising: a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises: means for detecting an electrical change between the counter electrode and the third electrode caused by supplying a sample liquid to the reaction layer; means for applying a voltage between the working electrode and the counter electrode after detecting the electrical change; and means for measuring a current flowing between the working electrode and the counter electrode.

Claim 11

A quantifying device for a substrate contained in a sample liquid comprising: a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises: means for detecting an electrical change between the counter electrode and the third electrode caused by supplying a sample liquid to the reaction layer; means for applying a voltage between the working electrode and the counter electrode after detecting the electrical change; and means for measuring a current flowing between the working electrode and the counter electrode.

Claim 12

A quantifying device according to claim 7, wherein the means for applying a voltage between the working electrode and the counter electrode applies the voltage while a voltage is continuously applied between the counter electrode and the third electrode.

Claim 13

A quantifying device for a substrate contained in a sample liquid, comprising a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises a measuring device to which the biosensor is removably connected, wherein the measuring device includes: current/voltage converting circuits connected to the third electrode of the biosensor; A/D converting circuits connected to the current/voltage converting circuits; current/voltage converting circuits which connects the working electrode of the biosensor via a switch; A/D converting circuits connected to the current/voltage converting circuits; and a controller connected to the respective A/D converting circuits, the switch being turned ON or OFF with respect to the working electrode by a control of the controller, and wherein an electrical change between the counter electrode and the third electrode, caused by a supply of a sample liquid to the reactive layer, is detected by the control portion under a condition that the switch is insulated from the working electrode, and then a voltage is applied between the working electrode and both of the third electrode and the counter electrode under a condition that the switch is connected to the working electrode and a current flowing between the working electrode and the counter electrode is measured.

Claim 14

A quantifying device for a substrate contained in a sample liquid, comprising a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises a measuring device to which the biosensor is removably connected, wherein the measuring device includes: current/voltage converting circuits connected to the third electrode of the biosensor; A/D converting circuits connected to the current/voltage converting circuits; current/voltage converting circuits which connects the working electrode of the biosensor via a switch; A/D converting circuits connected to the current/voltage converting circuits; and a controller connected to the respective A/D converting circuits, the switch being turned ON or OFF with respect to the working electrode by a control of the controller, and wherein an electrical change between the counter electrode and the third electrode, caused by a supply of a sample liquid to the reactive layer, is detected by the control portion under a condition that the switch is insulated from the working electrode, and then a voltage is applied between the working electrode and both of the third electrode and the counter electrode under a condition that the switch is connected to the working electrode and a current flowing between the working electrode and the counter electrode is measured.

Claim 15

A quantifying device according to claim 9, wherein the application of a voltage between the working electrode and both of the third electrode and the counter electrode is conducted while a voltage is continuously applied between the counter electrode and the third electrode.

Claim 16

A quantifying device for a substrate contained in a sample liquid, comprising a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises a measuring device to which the biosensor is removably connected, wherein the measuring device includes: current/voltage converting circuits connected to the third electrode of the biosensor; A/D converting circuits connected to the current/voltage converting circuits; current/voltage converting circuits which connects the working electrode of the biosensor via a switch; A/D converting circuits connected to the current/voltage converting circuits; and a controller connected to the respective A/D converting circuits, the switch being turned ON or OFF with respect to the working electrode by a control of the controller, and wherein an electrical change between the counter electrode and the third electrode, caused by a supply of a sample liquid to the reactive layer, is detected by the control portion under a condition that the switch is insulated from the working electrode, and then a voltage is applied between the working electrode and the counter electrode under a condition that the switch is connected to the working electrode and a current flowing between the working electrode and the counter electrode is measured.

Claim 17

A quantifying device for a substrate contained in a sample liquid, comprising a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises a measuring device to which the biosensor is removably connected, wherein the measuring device includes: current/voltage converting circuits connected to the third electrode of the biosensor; A/D converting circuits connected to the current/voltage converting circuits; current/voltage converting circuits which connects the working electrode of the biosensor via a switch; A/D converting circuits connected to the current/voltage converting circuits; and a controller connected to the respective A/D converting circuits, the switch being turned ON or OFF with respect to the working electrode by a control of the controller, and wherein an electrical change between the counter electrode and the third electrode, caused by a supply of a sample liquid to the reactive layer, is detected by the control portion under a condition that the switch is insulated from the working electrode, and then a voltage is applied between the working electrode and the counter electrode under a condition that the switch is connected to the working electrode and a current flowing between the working electrode and the counter electrode is measured.

Claim 18

A quantifying device according to claim 11, wherein the application of a voltage between the working electrode and the counter electrode is conducted while a voltage is continuously applied between the counter electrode and the third electrode.

Claim 19

A quantifying device for a substrate contained in a sample liquid, comprising a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises a measuring device to which the biosensor is removably connected, wherein the measuring device includes: current/voltage converting circuits switchably connected to the third electrode of the biosensor and the working electrode; A/D converting circuits connected to the current/voltage converting circuits; a controller connected to the respective A/D converting circuits, the switch being alternatively connected to the working electrode and the third electrode by a control of the controller, and wherein an electrical change between the counter electrode and the third electrode, caused by a supply of a sample liquid to the reactive layer, is detected by the control portion under a condition that the switch is connected to the third electrode, and then a voltage is applied between the working electrode and the counter electrode under a condition that the switch is connected to the working electrode and a current flowing between the working electrode and the counter electrode is measured.

Claim 20

A quantifying device for a substrate contained in a sample liquid, comprising a biosensor comprising: an electrically insulating substrate; an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction; and a reaction layer that is formed over at least the working electrode and the counter electrode of the electrode system and includes an oxidoreductase; wherein the quantifying device additionally comprises a measuring device to which the biosensor is removably connected, wherein the measuring device includes: current/voltage converting circuits switchably connected to the third electrode of the biosensor and the working electrode; A/D converting circuits connected to the current/voltage converting circuits; a controller connected to the respective A/D converting circuits, the switch being alternatively connected to the working electrode and the third electrode by a control of the controller, and wherein an electrical change between the counter electrode and the third electrode, caused by a supply of a sample liquid to the reactive layer, is detected by the control portion under a condition that the switch is connected to the third electrode, and then a voltage is applied between the working electrode and the counter electrode under a condition that the switch is connected to the working electrode and a current flowing between the working electrode and the counter electrode is measured.