JP4856011B2 - Biosensor - Google Patents

Description

  The present invention relates to a biosensor capable of quantitative analysis by measuring the amount of a specific component in a specimen.

  Conventionally, biosensors have been devised for measuring blood sugar levels and the like of specimens (see, for example, Patent Document 1 and Patent Document 2). According to this biosensor, a blood glucose level or the like can be measured by measuring a current value between the measurement working electrode and the measurement counter electrode when the reaction part reacts with blood or the like introduced from the supply port.

However, since the amount of blood and the like collected is small, it has been difficult for the conventional biosensor to confirm with the naked eye whether or not the collected blood or the like has been spotted on the biosensor. In addition, due to an insufficient amount of collected blood or the like, the amount of blood or the like introduced to the reaction part is small, so that accurate measurement may not be performed. In other words, even though the amount of blood introduced to the reaction part is not necessary for accurate measurement, the blood glucose level is measured and output, thereby recognizing an inaccurate measurement value as an accurate measurement value. There was a case.

Japanese Patent Publication No.8-10208 International Publication No. 2004/017057 Pamphlet

  Therefore, the inventor of the present invention has come to the present invention as a result of intensive studies to investigate the cause of such a problem and solve such a problem.

  That is, the present invention can easily recognize whether or not collected blood or the like is spotted on the biosensor, and whether or not the amount of blood or the like introduced to the reaction part is an amount necessary for accurate measurement. It is an object of the present invention to provide a biosensor that can accurately detect the odor.

The biosensor of the present invention includes a substrate made of an insulator, a measurement working electrode provided on the substrate, and a measurement counter electrode provided on the substrate at a predetermined interval from the measurement working electrode. A reaction portion provided on the working electrode for measurement and the counter electrode for measurement, and a supply port for introducing a sample to the reaction portion, and the reaction portion is attached to a measurement display, the Rukoto to react with the specific component in the introduced from the supply port analyte biosensor for quantitatively analyzing the particular component, on the opposite side to the supply opening to the measuring working electrode and measuring the counter electrode, A detection working electrode provided on the substrate; and a detection counter electrode provided on the substrate at a predetermined interval from the detection working electrode , the detection working electrode and the detection counter electrode. The reaction part is connected to the supply port Is detected based on the current value generated between the detection working electrode and the detection counter electrode by detecting the current value generated between the detection working electrode and the detection counter electrode. The measurement unit is capable of determining whether the amount of the introduced sample is equal to or greater than a predetermined threshold that is a predetermined amount necessary for the measurement, and the reaction unit includes the detection unit. The working electrode for measurement and the counter electrode for detection are disposed, and the working electrode for measurement and the counter electrode for measurement are arranged between the working electrode for detection and the counter electrode for detection, and the working electrode for detection and the counter electrode for detection Is provided so as not to contact the measuring working electrode and the measuring counter electrode .

Furthermore, the biosensor of the present invention is the above-described biosensor, the working electrode for spotting detection provided on the substrate on the supply port side with respect to the working electrode for measurement and the counter electrode for measurement, A working electrode for spotting detection on the substrate and a counter electrode for spotting detection provided at a predetermined interval;
The introduction of the specimen is detected by the detection working electrode, the detection counter electrode, the spotting detection working electrode, and the spotting detection counter electrode .

Furthermore, the biosensor according to the present invention is characterized in that, in the biosensor, the reaction portion contacts the working electrode for spotting detection and the counter electrode for spotting detection .

In the biosensor of the present invention, the tip of the detection working electrode is disposed in a substantially semicircular cutout provided on the opposite side of the supply port in the measurement working electrode. The tip of the counter electrode for detection is arranged in a substantially semicircular cutout provided on the opposite side of the supply port in the counter electrode for measurement .

  According to the biosensor of the present invention, it is possible to detect the spotting of the specimen to the supply port using the spotting detection working electrode and the spotting detection counter electrode. For this reason, it can be easily recognized whether the collected blood or the like has been spotted on the biosensor. In addition, on the condition that the specimen is spotted on the supply port, it is possible to start detecting whether or not the amount of blood or the like introduced to the reaction part by the detection electrode is an amount necessary for accurate measurement. Thereby, it is possible to accurately detect whether or not the amount of introduced blood or the like is an amount necessary for accurate measurement.

  Next, the biosensor according to the present invention will be described in detail based on the drawings. 1 and 2, reference numeral 10 denotes a biosensor of the present invention.

The biosensor 10 of the present invention includes a substrate 12 made of an insulator, a measurement working electrode 14 provided on the substrate 12, and a measurement working electrode 14 provided on the substrate 12 with a predetermined interval. A counter electrode 16, a measurement working electrode 14, a reaction part 18 provided on the measurement counter electrode 16, and a supply port 20 for introducing blood (specimen) to the reaction part 18, are supplied by the reaction part 18. It is a biosensor that reacts with a specific component in blood introduced from the mouth 20 and quantitatively analyzes the specific component. In this biosensor 10, the detection working electrode 22 provided on the substrate 12 and the detection working electrode on the substrate 12 on the side opposite to the supply port 20 with respect to the measurement working electrode 14 and the measurement counter electrode 16. 22, a counter electrode for detection 24 provided at a predetermined interval, and a working electrode for spotting detection provided on the substrate 12 on the supply port side 20 with respect to the measurement working electrode 14 and the measurement counter electrode 16 50, a spotting detection working electrode 50 on the substrate 12 and a spotting detection counter electrode 52 provided at a predetermined interval, and a detection working electrode 22, a detection counter electrode 24, and spotting detection. The introduction of blood is detected by the working electrode 50 and the counter electrode 52 for spotting detection. Therefore, the detection working electrode 22 and the detection counter electrode 24 constitute a detection electrode.

The insulator constituting the substrate 12 is, for example, polyethylene terephthalate (PET), polyethylene naphthalate, a polyester resin sheet such as a biodegradable polyester resin composed of an aliphatic unit and an aromatic unit, more heat resistance, chemical resistance, Examples thereof include a polyamideimide sheet having excellent strength, a plastic sheet such as a polyimide film sheet, and an inorganic substrate such as ceramic.

  The measuring working electrode 14 and the measuring counter electrode 16 are each formed in a substantially semicircular shape, and both form a substantially circular shape. The measuring working electrode 14 and the measuring counter electrode 16 are formed on the electrically insulating substrate 12 by a good conductor such as platinum, gold, palladium, indium-tin oxide, or the like. As a forming method, hot stamping or the like can be considered, but a method by vacuum deposition or sputtering is preferable because a fine electrode pattern can be formed with high accuracy. In the case of sputtering, it can be formed at once by masking the outside of the formation of both electrodes.

  The reaction unit 18 includes an oxidoreductase and an electron acceptor. For example, it is configured by applying and drying a liquid material containing an oxidoreductase and an electron acceptor. Examples of the oxidoreductase include glucose oxidase when measuring glucose. Glucose oxidase reacts with glucose to produce gluconic acid and hydrogen peroxide. Moreover, when measuring an alcohol value, alcohol oxidase or alcohol dehydrogenase is used. When measuring lactic acid, lactate oxidase or lactate dehydrogenase is used. When measuring uric acid, uricase is used. Examples of the electron acceptor include alkali metal ferricyanide (particularly potassium ferricyanide metal salt), ferrocene or an alkyl-substituted product thereof, p-benzoquinone, methylene blue, potassium β-naphthoquinone-4-sulfonate, phenazine metho. Examples include sulfate, 2,6-dichlorophenol-indophenol, and the like. Ferricyanide alkali metal salts and ferrocenes have a stable function as an electron transfer medium and are well soluble in aqueous solvents such as water, alcohols, or mixed solvents thereof, and thus effectively function as electron acceptors.

  As shown in FIG. 1, the supply port 20 includes a leading edge 31 of a cover 28 provided on the substrate 12 via a spacer 26 and a leading edge 33 of the substrate 12. That is, the supply port 20 is configured by a gap generated between the leading edge 31 and the leading edge 33 by the spacer 26. The blood introduced from the supply port 20 can reach the tip edge 35 of the spacer 26 by capillary action.

  As shown in FIG. 1, the detection working electrode 22 and the detection counter electrode 24 are not in contact with the measurement working electrode 14 and the measurement counter electrode 16 while sandwiching the measurement working electrode 14 and the measurement counter electrode 16. Is provided. The tip of the detection working electrode 22 enters a substantially semicircular cutout provided on the opposite side of the supply port 20 in the measurement working electrode 14, and the tip of the detection counter electrode 24 is in the measurement working electrode 14. It enters a substantially semicircular cutout provided on the side opposite to the supply port 20.

The reaction part 18 is in contact with the detection working electrode 22 and the detection counter electrode 24, and not when the blood directly contacts the detection working electrode 22 and the detection counter electrode 24. Is configured to detect the amount of blood introduced by detecting the current value between the detection working electrode 22 and the detection counter electrode 24 when it reacts with blood introduced from the supply port 20. The materials of the detection working electrode 22 and the detection counter electrode 24 are the same as the materials of the measurement working electrode 14 and the measurement counter electrode 16 described above.

  The spotting detection working electrode 50 and the spotting detection counter electrode 52 are curved along the outer periphery of the measurement working electrode 14 and the measurement counter electrode 16 as shown in FIG. It is provided so as not to contact the counter electrode 16 for use. The tips of the spotting detection working electrode 50 and the spotting detection counter electrode 52 are located in the vicinity of the center of the supply port 20, and are configured to be positions where blood is usually spotted first.

The reaction unit 18 is in contact with the spotting detection working electrode 50 and the spotting detection counter electrode 52, and blood directly contacts the spotting detection working electrode 50 and the spotting detection counter electrode 52. Not only when the reaction unit 18 reacts to the blood introduced from the supply port 20, but detects the current value between the spotting detection working electrode 50 and the spotting detection counter electrode 52 to introduce blood. Is configured to detect. The materials of the spotting detection working electrode 50 and the spotting detection counter electrode 52 are the same as the materials of the measurement working electrode 14 and the measurement counter electrode 16 described above.

  The biosensor 10 includes a measurement working electrode 14 and a measurement counter electrode 16, a detection working electrode 22 and a detection counter electrode 24, and a spotting detection working electrode 50 and a spotting detection counter electrode 52 on a substrate 12. The reaction portion 18 is applied on the measurement working electrode 14 and the measurement counter electrode 16, the detection working electrode 22 and the detection counter electrode 24, and the spotting detection working electrode 50 and the spotting detection counter electrode 52. Then, it is formed by covering with a cover 28 via a spacer 26.

In addition, when the blood glucose level is measured, such a biosensor 10 is inserted into the sensor mounting opening of the measurement display 30 so that the measurement is integrated with the measurement working electrode 14 as shown in FIG. The working electrode terminal 32 is connected to the control means 36 via the switch 34 and the like, and the measuring counter electrode terminal 38 integrated with the measuring counter electrode 16 is connected to the control means 36 via the switch 40 and the like, and the detection working electrode 22 is connected to the control means 36 via a switch 44 or the like, and the detection counter electrode terminal 46 integral with the detection counter electrode 24 is connected to the control means 36 via a switch 48 or the like. The spotting detection working electrode terminal 54 integrated with the spotting detection working electrode 50 is connected to the control means 36 via the switch 56 and the like, and is integrated with the spotting detection counter electrode 52 for spotting detection. Use the electrode terminal 58 is connected to the control unit 36 via the switch 60 and the like.

  The operation of measuring the blood glucose level using the biosensor 10 having such a configuration will be described below. The blood glucose level measurer first inserts the biosensor 10 into the sensor mounting opening of the measurement display 30 and puts the blood pierced into the fingertip near the center of the supply port 20 of the biosensor 10. To spot. The blood spotted in the vicinity of the center of the supply port 20 flows through the gap between the substrate 12 and the cover 28 along the reaction portion 20 toward the tip edge 35 of the spacer 26 due to capillary action. Then, it adheres to the supply port 20 side in the reaction section 18. At this time, the switches 56 and 60 are turned on and the switches 34, 40, 44 and 48 are turned off, and the supply port 20 side in the reaction unit 18 reacts with blood, or a working electrode for spotting detection. As a result of the transfer of electrons between 50 and the spotting detection counter electrode 52, a current is generated between the spotting detection working electrode 50 and the spotting detection counter electrode 52. The controller 36 recognizes the current value generated between the spotting detection working electrode 50 and the spotting detection counter electrode 52. When the control means 36 recognizes that the current value is equal to or greater than a certain value (threshold value), the control means 36 determines that blood has been spotted on the supply port 20, and the switches 44 and 48 are turned on, and the switches 34, 40 are turned on. , 56 and 60 are turned off, and blood detection by the detection working electrode 22 and the detection counter electrode 24 is started. When the current value generated between the spotting detection working electrode 50 and the spotting detection counter electrode 52 is less than a predetermined value (threshold value), a time is waited until the current value becomes equal to or greater than the predetermined value.

When the detection of the blood by the detection working electrode 22 and the detection counter electrode 24 is started and the amount of blood spotted on the supply port 20 is sufficient to accurately measure the blood glucose level, the reaction unit 18 near the supply port 20 on the side opposite to the supply port 20, blood reaches or reacts, or reacts well over the entire reaction unit 18, or between the detection working electrode 22 and the detection counter electrode 24. As a result of the transfer of electrons, a current is generated between the detection working electrode 22 and the detection counter electrode 24. The control means 36 recognizes the current value generated between the detection working electrode 22 and the detection counter electrode 24. If the control means 36 recognizes that the current value is equal to or greater than a predetermined value (threshold value) within a predetermined time, the amount of blood is sufficient to accurately measure the blood glucose level. The switches 34 and 40 are turned on and the switches 44, 48, 56 and 60 are turned off, and the blood glucose level measured by the measuring working electrode 14 and the measuring counter electrode 16 is displayed on the display means. Thereby, the measurer can read the blood glucose level with the recognition that the measured value is accurate.

  On the other hand, when the amount of blood spotted on the supply port 20 is insufficient to accurately measure the blood glucose level, it is opposite to the supply port 20 in the reaction unit 18 within a predetermined time period. The blood does not reach the side end portion and does not react, or does not react sufficiently over the entire reaction section 18, or the transfer of electrons between the detection working electrode 22 and the detection counter electrode 24 does not occur. Thus, no current is generated or only a small current is generated between the detection working electrode 22 and the detection counter electrode 24. If the control means 36 recognizes that the current value is less than a certain value after a predetermined period of time has elapsed, the control means 36 determines that the amount of blood is insufficient to accurately measure the blood sugar level. Then, the measurement person is made to recognize by the error display on the display means of the measurement display 30 or the like. In this case, the measurer removes and replaces the biosensor 10 from the measurement display 30 and performs measurement again.

  As mentioned above, although one Embodiment of this invention was described, this invention can be implemented also in another aspect. For example, as shown in FIG. 3, in the biosensor 10, the reaction unit 18 contacts only the measurement working electrode 14, the measurement counter electrode 16, the detection working electrode 22, and the detection counter electrode 24. May be provided in a narrow range. In this case, the spotting of the blood can be detected by the reaction unit 18 reacting with the blood and melting out to the periphery, or when the spotting detection working electrode 50 and the spotting detection counter electrode 52 are conducted.

  Further, the present invention may be the biosensor 100 shown in FIG. 4, the biosensor 110 shown in FIG. 5, and the biosensor 120 shown in FIG. In these biosensors 100, 110, and 120, only one detection electrode 102 is provided. In this case, by using the measurement working electrode 14 and the measurement counter electrode 16, the amount of blood accurately measures the blood glucose level by the detection electrode 102, the measurement working electrode 14 and the measurement counter electrode 16. It can be detected that the amount is sufficient.

  Further, the present invention is not limited to the illustrated embodiment. For example, the reaction unit 18 may contact only the measurement working electrode 14 and the measurement counter electrode 16 and may be provided in a narrower range than FIG. In this case, the spotting of the blood can be detected by the reaction unit 18 reacting with the blood and melting out to the periphery, or when the spotting detection working electrode 50 and the spotting detection counter electrode 52 are conducted. In addition, the technical scope of the present invention includes embodiments in which various improvements, modifications, and variations are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention. Moreover, you may implement with the form which substituted any invention specific matter to the other technique within the range which the same effect | action or effect produces.

  According to the biosensor of the present invention, it is possible to easily confirm whether or not the collected blood is spotted on the biosensor, and the amount of blood or the like introduced to the reaction part is an amount necessary for accurate measurement. Whether or not can be accurately detected. For this reason, it can be widely used for accurate measurement by a biosensor.

It is a front view of the biosensor of the present invention. It is a circuit diagram of the measurement indicator used for the biosensor of FIG. It is a front view which shows other embodiment of the biosensor of this invention. It is a front view which shows other embodiment of the biosensor of this invention. It is a front view which shows other embodiment of the biosensor of this invention. It is a front view which shows other embodiment of the biosensor of this invention.

Explanation of symbols

10, 100, 110, 120: biosensor 12: substrate 14: measuring working electrode 16: measuring counter electrode 18: reaction unit 20: supply port 22: detecting working electrode 24: detecting counter electrode 26: spacer 28: Cover 30: Measurement display device 50: Working electrode for spotting detection 52: Counter electrode for spotting detection

Claims (2)

A substrate made of an insulator, a measurement working electrode provided on the substrate, a measurement counter electrode provided on the substrate at a predetermined interval from the measurement working electrode, the measurement working electrode, and A reaction section provided on the counter electrode for measurement, and a supply port for introducing the specimen to the reaction section,
When attached to the measuring indicator, by Rukoto to react with the specific component in a sample reaction unit is introduced from the supply port, in a biosensor for quantitatively analyzing the specific component,
On the opposite side of the supply port to the measurement working electrode and the measurement counter electrode, the detection working electrode is provided on the substrate, and is provided on the substrate at a predetermined interval from the detection working electrode. A counter electrode for detection ,
The detection working electrode and the detection counter electrode detect a current value generated between the detection working electrode and the detection counter electrode when the reaction unit reacts to the sample introduced from the supply port. Based on the current value generated between the detection working electrode and the detection counter electrode, the measurement indicator displays whether the amount of the introduced sample is equal to or greater than a certain threshold which is a predetermined amount necessary for the measurement. So that it can be discriminated by the control means of
The reaction portion is in contact with the detection working electrode and the detection counter electrode;
The measurement working electrode and the measurement counter electrode are arranged between the detection working electrode and the detection counter electrode, and the detection working electrode and the detection counter electrode are connected to the measurement working electrode and the measurement counter electrode. Provided in a form that does not contact
On the supply port side with respect to the measurement working electrode and the measurement counter electrode, a spotting detection working electrode provided on the substrate, and a predetermined distance from the spotting detection working electrode on the substrate A counter electrode for spotting detection provided in a space;
Detecting the introduction of the specimen by the detection working electrode, the detection counter electrode , the spotting detection working electrode and the spotting detection counter electrode,
The biosensor in which the reaction part contacts the working electrode for spotting detection and the counter electrode for spotting detection . The tip of the detection working electrode is arranged in a substantially semi-circular cutout provided on the opposite side of the supply port in the measurement working electrode, and the tip of the detection counter electrode is opposite to the measurement counter electrode. The biosensor according to claim 1, wherein the biosensor is disposed in a substantially semicircular cutout provided on the opposite side of the electrode from the supply port .

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