WO2021241224A1

WO2021241224A1 - Electrochemical sensor unit

Info

Publication number: WO2021241224A1
Application number: PCT/JP2021/018001
Authority: WO
Inventors: 淳益子; 開浅井
Original assignee: 株式会社ファーストスクリーニング
Priority date: 2020-05-27
Filing date: 2021-05-12
Publication date: 2021-12-02
Also published as: JP2021188957A; JP6749721B1; JP2021189159A

Abstract

The present invention comprises a substrate, a sensor electrode that is provided on one of two principal surfaces of the substrate, and a sheet that has an intake port for taking in a liquid test sample and is provided on the one surface of the substrate so as to cover the sensor electrode. A circumferential edge part of the sheet is bonded to the substrate to form a holding structure that holds the test sample taken in through the intake port and allows the test sample to contact the sensor electrode. The holding structure has a discharge port that discharges a portion of the test sample taken in through the intake port.

Description

Electrochemical sensor unit

The present disclosure relates to an electrochemical sensor unit that measures the concentration of a specific component contained in a liquid test sample.

In recent years, an electrochemical sensor unit including a base material, a sensor electrode mounted on the base material, and a sheet provided so as to cover the sensor electrode has been published as a patented technology (Patent Document 1). reference). In this sensor unit, a liquid test sample (test substance solution) taken in from an intake provided in the sheet is brought into contact with the sensor electrode, and the concentration of a specific component contained in the test sample is measured.

Japanese Patent No. 6653847

The above-mentioned patented technology contributes widely to the industry in that the concentration of a specific component in a test sample can be measured easily and reliably, but in rare cases, the concentration of the specific component itself does not change. However, it was found that the measurement result of the concentration may not be stable. This is a new issue that was first revealed by the inventor's diligent research. It is an object of the present disclosure to provide an electrochemical sensor unit capable of more stably and accurately measuring the concentration of a specific component in a test sample.

According to one aspect of the present disclosure
With the base material
A sensor electrode provided on one of the two main surfaces of the base material, and
An intake capable of taking in a liquid test sample is opened, and a sheet provided on one surface of the substrate so as to cover the sensor electrode is provided.
A storage structure is configured in which the peripheral edge of the sheet and the base material are adhered to each other to store the test sample taken in from the intake and bring it into contact with the sensor electrode.
The storage structure provides an electrochemical sensor unit having a discharge port for discharging a part of a test sample taken in through the intake.

According to the present disclosure, it is possible to provide an electrochemical sensor unit capable of more stably and accurately measuring the concentration of a specific component in a test sample.

It is an exploded perspective view of the electrochemical sensor unit in one aspect of this disclosure. It is a schematic top view of the electrochemical sensor unit in one aspect of this disclosure. It is an enlarged top view of the portion where the sensor electrode of the electrochemical sensor unit in one aspect of the present disclosure is arranged. The amount of urine to be brought into contact with the sensor electrode is set to high, medium, and low, and each cyclic voltammetry obtained by performing cyclic voltammetry is shown. FIG. 3 is a schematic top view of an electrochemical sensor unit in a modified example of one aspect of the present disclosure.

<Findings obtained by the inventor>
As described above, when a sensor unit having a structure with a sheet is used, the measurement result of the concentration may not be stable even though the concentration itself of the specific component in the test sample does not change. It was found that the concentration of a specific component may be measured as a concentration higher than the actual concentration or as a concentration lower than the actual concentration. The inventor has conducted diligent research on the factors behind this new issue. As a result, in the sensor structure having a structure with a sheet covering the sensor electrodes, the sensor unit having another structure, for example, the structure with a sheet is not provided, and the electrode portion is immersed in the test sample stored in the container. It was found that the amount of the test sample that comes into contact with the sensor electrode tends to fluctuate more easily than the sensor unit of the type that allows the sensor unit to be contacted, and this may be one factor that affects the measurement result of the concentration. .. This disclosure is based on this finding.

<One aspect of the present disclosure>
Hereinafter, one aspect of the present disclosure will be described mainly with reference to FIGS. 1 to 3. In this embodiment, an electrochemical sensor unit that measures the concentration of a specific component contained in a liquid test sample by a three-electrode method will be described as an example.

(1) Configuration of Electrochemical Sensor Unit As shown in FIG. 1, the electrochemical sensor unit (hereinafter, unit) 100 in this embodiment includes a base material 10, a sensor electrode 20, and a sheet 30. The unit 100 is configured to be disposable.

The unit 100 is used by connecting a measuring instrument configured to be able to perform a predetermined voltage sweep operation to the sensor electrode 20. The unit 100 brings a liquid test sample (urine collected from the subject as an example in this embodiment) into contact with the sensor electrode 20, and performs a predetermined voltage sweep operation on the sensor electrode 20 from the measuring device to perform urine. A specific component contained therein (uric acid as an example in this embodiment) is electrolyzed under specific conditions, and the concentration of uric acid is measured by a measuring instrument from the magnitude of the electrochemical reaction (for example, redox reaction) that occurs at that time. can do.

The base material 10 is configured to support the sensor electrode 20. The base material 10 is made of a sheet-shaped (plate-shaped) member and is formed in a longitudinal shape. The base material 10 has, for example, a longitudinal shape portion (main portion) 11 and a convex portion 12. The convex portion 12 is a portion that is sandwiched by a connection portion of a measuring instrument, which will be described later, or is inserted into an insertion port of the measuring instrument, that is, a portion that functions as a connection terminal.

The length of the main portion 11 is, for example, 90 mm or more and 150 mm or less, the width of the main portion 11 is, for example, 6 mm or more and 12 mm or less, and the thickness of the main portion 11 is, for example, 0.2 mm or more and 2 mm or less, preferably 0.3 mm or more and 1 mm or less. Can be. In the present specification, when the word "length" is used, it means the length in the longitudinal direction of the base material 10, and when the word "width" is used, the length in the width direction of the base material 10 is used. Means.

The length of the convex portion 12 may be, for example, 5 mm or more and 15 mm or less, and the width of the convex portion 12 and the thickness of the convex portion 12 may be the same width and thickness as, for example, the main portion 11. When the convex portion 12 is inserted into the insertion port of the measuring instrument, the width of the convex portion 12 is, for example, about 2 mm to 4 mm narrower than the width of the main portion 11, although it depends on the shape of the insertion port and the like. Can be width. The crank portion is configured by the difference between the width of the main portion 11 and the width of the convex portion 12, and this crank portion limits the insertion length when the convex portion 12 is inserted into the insertion port of the measuring instrument. Functions as a stopper. Further, for example, the thickness of the convex portion 12 may be made thinner than the thickness of the main portion 11, and the crank portion may be formed by the difference between the thickness of the main portion 11 and the thickness of the convex portion 12.

The base material 10 has a physical (mechanical) strength that can be used as a unit 100, for example, a strength that does not bend or break even when urine adheres. The base material 10 is made of an insulating material. As the insulating material, plastic, glass epoxy resin, ceramic, glass or the like can be used. As the base material 10, for example, a rigid substrate or a flexible substrate can be used.

The sensor electrode 20 is provided on one of the two main surfaces of the base material 10. Hereinafter, the main surface of the base material 10 on which the sensor electrode 20 is provided is also referred to as “the upper surface of the base material 10”. The sensor electrode 20 is provided on one end side in the longitudinal direction of the base material 10. Specifically, the sensor electrode 20 is provided on the main portion 11 of the base material 10 and in the vicinity of the end portion on the side opposite to the convex portion 12 in the longitudinal direction of the base material 10.

On the upper surface of the base material 10, three wirings (conductor wirings) 13, 14, 15 (hereinafter, also referred to as wirings 13 to 15) are arranged from above the convex portion 12 of the base material 10 toward the sensor electrode 20. They are provided apart from each other without contacting each other. From the viewpoint of reliably connecting the unit 100 and the measuring instrument described later, it is preferable that the wirings 13 to 15 are provided up to the end of the convex portion 12 opposite to the side adjacent to the main portion 11. ..

Wiring 13 to 15 can be formed by using a metal such as copper (Cu) or aluminum (Al). The wirings 13 to 15 may be made of the same material or may be made of different materials.

Wiring 13 to 15 uses, for example, a subtractive method in which an unnecessary portion of the copper film previously attached on the base material 10 that is not covered with a resist is removed by etching to form a necessary conductor pattern. Can be formed. Further, the wirings 13 to 15 can also be formed by using an additive method or the like. Further, for example, gold (Au) plating or silver (Ag) plating may be applied onto these conductor patterns formed by using the subtractive method or the additive method. Further, the wirings 13 to 15 can also be formed by a printing method such as screen printing, gravure printing, offset printing, inkjet printing, a vapor deposition method, or the like.

The sensor electrode 20 has a working electrode 21, a counter electrode (counter electrode) 22, and a reference electrode 23. One end of the wiring 13 is connected to the working electrode 21, one end of the wiring 14 is connected to the counter electrode 22, and one end of the wiring 15 is connected to the reference electrode 23.

As the working electrode 21, for example, an electrode made of Ag, Au, platinum (Pt), or Cu metal can be used. As the working electrode 21, a carbon electrode, a conductive diamond electrode doped with boron (B), or the like can also be used. Further, as the working electrode 21, an electrode or the like made of various known materials depending on the type of the specific component to be measured can also be used. The working electrode 21 can be formed by using a known method such as an additive method and a subtractive method. The working electrode 21 can be formed by, for example, applying a predetermined plating to a conductor pattern integrally formed with the wiring 13 by using a subtractive method. The working electrode 21 can also be formed by attaching a predetermined material to a conductor pattern integrally formed with the wiring 13 described later.

Further, on the surface of the working electrode 21, a predetermined surface decorative film such as an enzyme-containing film or an ion exchange membrane is formed as a functional film that allows only a specific component (for example, uric acid) to permeate or reacts only with this specific component. It may be provided.

The counter electrode 22 is an electrode for passing a current generated by an electrochemical reaction to the working electrode 21, and is provided so as to surround the working electrode 21 and the reference electrode 23 described later. The electrode area of the counter electrode 22 is preferably larger than the electrode area of the working electrode 21. As the counter electrode 22, an electrode made of a metal such as Pt, Au, Cu, palladium (Pd), nickel (Ni), Ag, or a carbon electrode can be used. The counter electrode 22 can be integrally formed with the wiring 14 by a known method such as a subtractive method or an additive method.

The reference electrode 23 is a reference electrode for determining the potential of the working electrode 21, and is provided in the vicinity of the working electrode 21. As the reference electrode 23, a silver / silver chloride (Ag / AgCl) electrode or the like can be used. Further, as the reference electrode 23, a standard hydrogen electrode, a reversible hydrogen electrode, a palladium / hydrogen electrode, a saturated calomel electrode, a carbon electrode and the like can also be used. Further, as the reference electrode 23, an electrode made of a metal such as Pt, Au, Cu, Pd, Ni, Ag or the like can also be used. The reference electrode 23 can be formed by attaching a predetermined material (for example, AgCl) to a conductor pattern integrally formed with the wiring 15 by using a subtractive method, an additive method, or the like. Further, for example, the conductor pattern integrally formed with the wiring 15 can be plated with gold or the like and used as the reference electrode 23.

A sheet-shaped waterproof member 40 is provided on the upper surface of the base material 10 to prevent urine from adhering to the wirings 13 to 15. The waterproof member 40 is configured to cover (seal) the wirings 13 to 15 located on the main portion 11 and expose the wirings 13 to 15 and the sensor electrode 20 located on the convex portion 12. The waterproof member 40 can be formed by using a water-impermeable and insulating material such as plastic, silicon resin, Teflon (registered trademark) resin, and rubber.

A sheet (sheet-like member) 30 is provided on the upper surface of the base material 10 so as to cover the sensor electrode 20 and the waterproof member 40. The sheet 30 includes a water-repellent member 31 that does not absorb urine and a water-absorbing member 32 that absorbs urine.

The water repellent member 31 can be, for example, a sheet shape (plate shape). The length of the water-repellent member 31 is set to be, for example, about 15 mm to 25 mm longer than the length of the base material 10 (the total length of the length of the main portion 11 and the length of the convex portion 12), and the water-repellent member 31 is set. It is preferable to dispose of the convex portion 12 so as to protrude from the side. As a result, when the unit 100 is connected to the measuring instrument, the portion of the water-repellent member 31 protruding from the convex portion 12 (hereinafter, also referred to as “the protruding portion of the water-repellent member 31 (or the sheet 30)”) is pinched. It can be turned over, and a part of the upper surface of the base material 10, for example, the convex portion 12 that functions as a connection terminal can be easily exposed. Further, when the unit 100 is connected to the measuring instrument, the connection portion (insertion port, holding portion, etc.) of the measuring instrument can be covered with the water repellent member 31. As a result, it is possible to prevent the infiltration of urine into the measuring instrument, and it is possible to improve the reliability of the measurement and the like. Further, when performing measurement, the finger of the subject holding (holding) the unit (measuring instrument connected to the unit) can be covered with the water-repellent member 31, and urine adheres to the subject's finger. It is also possible to prevent. The length of the water-repellent member 31 may be the same as the length of the base material 10. The width of the water-repellent member 31 can be the same as the width of the base material 10 (main portion 11). The thickness of the water-repellent member 31 can be, for example, 0.01 mm or more and 0.3 mm or less.

The water-repellent member 31 can be formed by using a paper whose surface is coated with a water-repellent material such as plastic, silicon resin, or Teflon (registered trademark) resin. As the water-repellent member 31, a sheet-shaped resin formed of the above-mentioned water-repellent material can also be used.

The water-repellent member 31 is provided with an intake (opening) 33 capable of taking in urine. The intake 33 is provided so as to be located on the sensor electrode 20 when the sheet 30 is arranged. The intake 33 can be, for example, a circular shape having a diameter of 2 mm or more and 5 mm or less. The intake 33 is not limited to a circular shape, but may be a rectangular shape or the like.

The water-repellent member 31 is provided (attached) with a water-absorbing member 32 so as to close the intake 33. The water absorbing member 32 is formed in a sheet shape, for example, and is configured to absorb urine supplied to the unit 100 and bring it into contact with the surface of the sensor electrode 20. The water absorbing member 32 has a size that covers at least a part of the surface of the sensor electrode 20 (working electrode 21, counter electrode 22, and reference electrode 23). The water absorbing member 32 may be provided on the front surface side of the water repellent member 31, but as shown in FIG. 1 and the like, it is preferable to provide the water absorbing member 32 on the back surface (the surface facing the base material 10) of the water repellent member 31. In this case, the water absorbing member 32 will be arranged inside the storage structure described later, and will function to reliably store urine in the storage structure.

By adjusting the flat area and the thickness of the water absorbing member 32, it becomes possible to easily control the amount of urine stored in the storage structure, that is, the amount of urine that comes into contact with the sensor electrode 20. .. As shown in FIG. 1 and the like, the flat area of the water absorbing member 32 is preferably a flat area larger than the flat area of the sensor electrode 20. The flat area of the water absorbing member 32 can be, for example, 10 mm ² or more and 50 mm ² or less. This makes it possible to reliably bring urine into contact with the entire surface of the sensor electrode 20 and increase the sensitivity of concentration measurement. The flat area of the water absorbing member 32 may be smaller than the flat area of the sensor electrode 20. The thickness of the water absorbing member 32 can be, for example, 0.01 mm or more and 1.0 mm or less.

When the water absorbing member 32 is attached to the water repellent member 31 using an adhesive, it is preferable that the position where the adhesive is applied is a position not facing the sensor electrode 20. Further, the water absorbing member 32 may be attached to the water repellent member 31 without using an adhesive. For example, the water absorbing member 32 may be attached to the water repellent member 31 by providing a notch in the water repellent member 31, inserting the water absorbing member 32 into the notch, and sandwiching the water absorbing member 32 between the water repellent members 31. .. By doing so, it is possible to reduce the adverse effect of the substance contained in the adhesive on the measurement result.

The water absorbing member 32 can be formed by using natural fiber, pulp fiber, regenerated fiber, synthetic fiber and the like. Specifically, the water absorbing member 32 can be formed by using a filter paper, a membrane filter, a glass filter, a filter cloth, or the like. The water-absorbing member 32 can also be formed by adding water-absorbing polymer particles or the like to the above-mentioned aggregate composed of one or more fibers. The water absorbing member 32 may be formed by using a member made of a porous material such as sponge or diatomaceous earth, or a fiber material such as a non-woven fabric.

As shown in FIGS. 2 and 3, the peripheral edge portion of the sheet 30 (that is, the water repellent member 31) and the base material 10 are adhered to each other via an adhesive 51 or the like. Specifically, the peripheral edge portion of the sheet 30, the peripheral edge portion of the central portion in the longitudinal direction of the base material 10, and the peripheral edge portion on the side where the sensor electrode 20 is provided are adhered to each other via the adhesive 51. .. As a result, the urine taken in from the intake 33 is stored in the space between the base material 10 and the sheet 30 (in the place where the waterproof member 40 is arranged, between the waterproof member 40 and the sheet 30). A storage structure (bag-shaped structure) that comes into contact with the sensor electrode 20 is configured. Adhesion between the sheet 30 and the base material 10 is not limited to the case where the adhesive 51 is used, but can be performed by various methods such as heat fusion, sewing, and fitting. In FIG. 3, the sheet 30 and the waterproof member 40 are omitted for the sake of clarity.

The storage structure has a discharge port 52 for discharging a part of urine taken into the storage structure via the intake 33. The discharge port 52 is configured so that the amount of urine in contact with the sensor electrode 20 can be adjusted. The discharge port 52 stores excess urine that has been taken into the storage structure via the intake 33 and cannot be completely absorbed by the water absorbing member 32 to the outside of the storage structure (unit 100), thereby storing the excess urine in the storage structure. The amount of urine to be produced, that is, the amount of urine to be brought into contact with the sensor electrode 20, is configured to be constant (predetermined amount). This makes it possible to prevent fluctuations in the measurement result of the uric acid concentration in urine and to accurately and stably measure the uric acid concentration in urine. That is, it is possible to stabilize the measurement accuracy of the uric acid concentration by the unit 100.

If the storage structure is not provided with the discharge port 52, it becomes difficult to adjust the amount of urine in contact with the sensor electrode 20, and the amount of urine in contact with the sensor electrode 20 becomes excessive (predetermined amount). May exceed). In this case, although the actual uric acid concentration in urine does not change (the concentration does not increase), the output of the detection signal of the unit 100 becomes larger than expected, and the uric acid concentration is measured higher than the actual concentration. May be done. On the other hand, in this embodiment, since the amount of urine in contact with the sensor electrode 20 can be adjusted to be a constant amount by using the discharge port 52, the measurement of the uric acid concentration in urine can be accurately and accurately performed. It will be possible to do it stably.

The discharge port 52 can be configured by using various known check valves, but as shown in FIGS. 1 to 3, etc., the discharge port 52 is based on a part of the peripheral portion of the sheet 30 constituting the storage structure. It can be configured by making it non-adhesive to the material 10. With such a configuration, the discharge port 52 can be easily provided, and the unit 100 can be avoided from becoming complicated, large in size, and costly.

It is preferable that the discharge port 52 is arranged at a position where the sensor electrode 20 is arranged on the flow path of urine from the intake port 33 to the discharge port 52. That is, it is preferable that the sensor electrode 20 is arranged on the flow path of urine from the intake 33 to the discharge port 52. As a result, the amount of urine that comes into contact with the sensor electrode 20 can be reliably made constant, and the uric acid concentration in urine can be measured accurately and stably.

When the sensor electrode 20 is not arranged on the urine flow path, the urine taken in from the intake 33 becomes difficult to reach the sensor electrode 20, and the amount of urine in contact with the sensor electrode 20 becomes too small (predetermined amount). May be less than). In this case, although the actual uric acid concentration in urine does not change (the concentration does not decrease), the output of the detection signal of the unit 100 becomes smaller than expected, and the uric acid concentration is measured lower than the actual concentration. May be done. Further, when the sensor electrode 20 is not arranged on the urine flow path, excess urine that should pass on the sensor electrode 20 is less likely to be discharged from the discharge port 52, and a large amount of urine remains on the sensor electrode 20. As a result, the amount of urine that comes into contact with the sensor electrode 20 may become excessive. In this case, although the actual uric acid concentration in urine does not change (the concentration does not increase), the output of the detection signal of the unit 100 becomes larger than expected, and the uric acid concentration is measured higher than the actual concentration. May be done. If the sensor electrode 20 is not arranged on the urine flow path as described above, the measurement accuracy of the uric acid concentration by the unit 100 may become unstable. On the other hand, in this embodiment, since the sensor electrode 20 is arranged on the urine flow path, the amount of urine in contact with the sensor electrode 20 can be ensured to a constant amount, and the uric acid concentration in urine can be measured. Can be performed accurately and stably.

The position and size of the discharge port 52 are such that the discharge port 52 overlaps with at least a part of the sensor electrode 20 when the unit 100 is viewed from the side surface side (when the unit 100 is viewed from the side surface). It is preferable that the discharge port 52 is positioned and sized so as to include all of the sensor electrodes 20.

Further, it is preferable that the discharge ports 52 are provided at a plurality of positions so that excess urine in the storage space can be smoothly discharged regardless of the posture of the unit 100. For example, as in this embodiment, the discharge port 52 has a direction orthogonal to the longitudinal direction of the base material 10 (width of the base material 10) when the unit 100 is viewed from the sheet 30 side (when the unit 100 is viewed in a plane). It is preferable to provide it on both sides of the direction). That is, it is preferable that the discharge ports 52 are provided on both sides of the base material 10 in the width direction with the sensor electrode 20 interposed therebetween when the unit 100 is viewed in a plan view.

By adopting at least one of these configurations, the excess urine taken into the storage structure can be drained without tilting or shaking the unit 100 after urine is applied. In addition, it becomes possible to perform more reliably regardless of the posture of the unit 100. That is, the above-mentioned action and effect of making the amount of urine in contact with the sensor electrode 20 constant by discharging using the discharge port 52 and accurately and stably measuring the uric acid concentration in urine is applied to the artificial operation of the subject or the like. It will be more reliable and natural without relying on it.

The size of the discharge port 52 can be appropriately set according to the size (flat area) of the water absorption member 32, the water absorption capacity (capacity of urine that can be absorbed), and the like. For example, when the excess space in the storage structure is large, the flat area of the water absorption member 32 is small, or the water absorption capacity of the water absorption member 32 is low, that is, excess urine tends to remain in the storage structure and comes into contact with the sensor electrode 20. If the amount of urine to be collected tends to be excessive, the size of the discharge port 52 (the length of the non-adhesive portion) may be longer than the length of the water absorbing member 32 in the longitudinal direction of the base material 10. Further, when the excess space in the storage structure is small, the flat area of the water absorption member 32 is large, and the water absorption capacity of the water absorption member 32 is high, that is, excess urine is unlikely to remain in the storage structure and comes into contact with the sensor electrode 20. If the amount of urine produced is likely to be too small, the size of the discharge port 52 may be shorter than the length of the water absorption member 32 in the longitudinal direction of the base material 10. As a result, it becomes easy to make the amount of urine in contact with the sensor electrode 20 appropriate and constant, and it becomes possible to measure the uric acid concentration more accurately and stably.

The peripheral edge of the sheet 30 and the base material 10 may have a non-adhesive portion in addition to the portion constituting the discharge port 52.

For example, in FIG. 2, when the vertical / horizontal direction of the paper surface is defined as the vertical / horizontal direction when the unit 100 is viewed in a plan view, the peripheral edge portion of the sheet 30 and the left end portion of the base material 10 may be non-adhesive. In the following, in FIG. 2, the left end portion of the base material 10 when the up / down / left / right direction of the paper surface is defined as the up / down / left / right direction when the unit 100 is viewed in a plan view is simply “the left end portion of the base material 10”. Also called. However, as shown in FIG. 2, by adhering this portion, it is possible to avoid the exposure of the sensor electrode 20 due to the turning of the edge of the sheet 30, and as a result, the sebum of the subject or the like adheres to the sensor electrode 20 and its sensitivity. It becomes possible to avoid a situation in which the sensor electrode 20 is lowered or the sensor electrode 20 is damaged.

Further, for example, as shown in FIG. 2, the peripheral edge portion of the sheet 30 and the peripheral edge portion of the convex portion 12 of the base material 10 and the peripheral edge portion of the peripheral edge portion of the main portion 11 on the convex portion 12 side are mutually aligned. It may be non-adhesive. This makes it easier to turn over the water-repellent member 31 to expose the convex portion 12.

In addition, as in this aspect, by adhering the sheet 30 and the base material 10 to each other at at least one place (preferably at two or more points), the relative positional deviation of the sheet 30 with respect to the base material 10 can be obtained. Needless to say, it can be suppressed and the reliability of the unit 100 can be maintained.

(2) Method for Measuring Uric Acid Concentration Using Electrochemical Sensor Unit Next, an example of a method for measuring uric acid concentration in urine by electrochemical measurement using the above-mentioned unit 100 will be described.

In the uric acid concentration measuring method using the unit 100,
The step (step 1) of electrically connecting the unit 100 and the measuring instrument,
The step of supplying urine to the unit 100 and bringing the urine into contact with the sensor electrode 20 (step 2),
With urine in contact with the surface of the sensor electrode 20, a predetermined voltage sweep operation is performed on the sensor electrode 20 from the measuring instrument to electrolyze the urine acid contained in the urine under specific conditions, which is generated at that time. The steps (step 3) of measuring the urinary acid concentration in urine from the magnitude of the electrochemical reaction are carried out in this order. In this embodiment, step 2, step 1, and step 3 may be performed in this order.

(Step 1)
In this step, the unit 100 and a measuring instrument (not shown) configured separately from the unit 100 are connected to each other. For example, the subject grips the unit 100 and pinches the protruding portion of the sheet 30 covering the base material 10 to expose the convex portion 12 of the base material 10 that functions as a connection terminal (see FIG. 2). A measuring instrument is connected to the convex portion 12. The measuring instrument is configured so that the connecting portion of the measuring instrument and the wirings 13 to 15 can be electrically connected only by sandwiching the convex portion 12 together with the wirings 13 to 15. The measuring instrument has an insertion port (slot) into which the convex portion 12 is inserted, and simply by inserting the convex portion 12 into the insertion port, the connection portion of the measuring instrument and the wirings 13 to 15 are electrically connected. It may be configured to be able to connect.

The measuring instrument is configured to be able to perform a predetermined voltage sweep operation on the sensor electrode 20, and includes a voltage sweep operation unit, a current measurement unit, a potential adjustment unit, a display unit, a wireless communication unit, and the like. ing. The above-mentioned parts of the measuring instrument are connected to each other so that data can be exchanged. The measuring instrument can transmit data indicating the concentration of uric acid obtained by the measurement to an external device (smartphone, tablet, PC, etc.) configured as a computer through a wireless communication means (wireless communication unit) or the like. It is configured as follows.

(Step 2)
After connecting the unit 100 and the measuring instrument, for example, the subject holds the measuring instrument and urinates toward the intake 33 of the unit 100. As a result, urine is supplied to the unit 100. The urine supplied to the unit 100 is taken into the storage structure from the intake 33 and absorbed by the water absorbing member 32. The urine absorbed by the water absorbing member 32 passes through the water absorbing member 32 and reaches the surface of the sensor electrode 20. As a result, urine comes into contact with the surface of the sensor electrode 20. Excess urine that cannot be completely absorbed by the water absorbing member 32 is discharged to the outside of the storage structure (unit 100) through the discharge port 52 of the storage structure. As described above, in this embodiment, the position and size of the discharge port 52 are set so that the discharge port 52 includes all of the sensor electrodes 20 when the unit 100 is viewed from the side. Further, when the unit 100 is viewed in a plan view, discharge ports 52 are provided on both sides of the base material 10 in the width direction with the sensor electrode 20 interposed therebetween. As a result, it becomes possible to more reliably discharge excess urine taken into the storage structure without relying on human operation.

Since the wirings 13 to 15 are covered with the waterproof member 40, even if urine flows toward the wirings 13 to 15 depending on the posture of the unit 100, the urine will be collected from the sheet 30 and the waterproof member. It will flow between 40 and 40. Therefore, urine hardly adheres to the wirings 13 to 15.

(Step 3)
With urine in contact with the surface of the sensor electrode 20, a predetermined voltage sweep operation is performed on the sensor electrode 20 from the measuring instrument to electrolyze the uric acid contained in the urine under specific conditions. The magnitude of the electrochemical reaction (eg, redox reaction) that occurs in is measured.

For example, when urine is in contact with the surface of the sensor electrode 20 (working electrode 21) and a voltage within a predetermined range is swept between the working electrode 21 and the reference electrode 23, a voltage within a predetermined range is applied under specific conditions (specific voltage). Is applied), uric acid is electrolyzed on the surface of the working electrode 21. When uric acid is electrolyzed, a current flows between the working electrode 21 and the counter electrode 22. The value of this current is continuously measured, for example, by a measuring instrument. The value of this current varies depending on the magnitude of the electrochemical reaction that occurs when uric acid is electrolyzed, and the larger the electrochemical reaction, the larger the value of the current.

Subsequently, the uric acid concentration is calculated based on the maximum value (peak value) of the current value measured by the measuring instrument. Since the current value correlates with the uric acid concentration, the uric acid concentration can be quantified based on the measured current value if the relationship between the current value and the uric acid concentration is obtained in advance. The measuring instrument displays the measured uric acid concentration on the display unit. Further, the measuring instrument can also transmit the uric acid concentration data obtained by the measurement to an external device via a wireless communication means or the like. When the measurement of the uric acid concentration by the measuring instrument is completed, the subject removes (extracts) the unit 100 from the measuring instrument and discards the unit 100.

(3) Effect According to this aspect, one or more of the following effects are exhibited.

(A) The unit 100 has a storage structure in which the peripheral edge portion of the sheet 30 and the base material 10 are adhered to each other, and urine taken in from the intake 33 is stored and brought into contact with the sensor electrode 20. Further, the storage structure includes a discharge port 52 for discharging a part of urine taken in through the intake 33. With these structures, the amount of urine that comes into contact with the sensor electrode 20 is kept constant (predetermined amount), and the uric acid concentration can be accurately and stably measured by the unit 100.

The inventor has confirmed that if the amount of urine in contact with the sensor electrode 20 is not constant, the measurement accuracy of the uric acid concentration by the unit 100 may become unstable. The experiments conducted to support this and the results are shown below.

This experiment was performed in a state where the sheet 30 was peeled off from the above-mentioned unit 100 and the surface of the sensor electrode 20 was exposed. First, a predetermined amount of urine was applied (dripping) to the exposed sensor electrode 20 using a dropper. At this time, the amount of urine dripping (supplied) on the sensor electrode 20 was different from large, medium, and small. In the case of "many", each of the surface and the side surface of the sensor electrode 20 was brought into full contact with urine. In the case of "medium", 90% or more of the surface of the sensor electrode 20 is in contact with urine, but the rest is exposed including the side surface. In the case of "small", about 50% of the surface of the sensor electrode 20 is in contact with urine, but the rest is exposed including the side surface. Then, cyclic voltammetry was performed in each of the "many", "medium", and "small" cases to obtain the cyclic voltammetry shown in FIG. All measurements were performed using the same unit 100. In addition, the measurement conditions other than the contact amount of urine (uric acid concentration in urine, sweep speed, sweep voltage range, measurement temperature, etc.) were all the same conditions.

In FIG. 4, the solid line shows the cyclic voltammogram when the contact amount is “high”, the broken line shows the cyclic voltamogram when the contact amount is “medium”, and the dotted line shows the cyclic voltamogram when the contact amount is “small”. There is. From FIG. 4, it can be seen that the measurement results vary when the amount of urine in contact with the surface of the sensor electrode 20 changes even though the actual uric acid concentration has not changed (the actual uric acid concentration is the same). .. That is, it can be seen that when the amount of urine in contact with the sensor electrode 20 is not constant, the measurement accuracy of the concentration of a specific component in the test sample (for example, the uric acid concentration in urine) by the unit 100 becomes unstable.

The above experimental results show that by keeping the amount of urine in contact with the sensor electrode 20 using the discharge port 52 constant, the uric acid concentration can be measured accurately and stably. It is a proof.

(B) When urine is poured into the unit 100 and taken into the storage structure from the intake 33, the urine excessively taken into the storage structure is quickly (in real time) discharged using the discharge port 52. It becomes possible. As a result, stress applied to various members such as the sheet 30 constituting the storage structure can be reduced, deformation of the sheet 30 and peeling from the base material 10 can be avoided, and as a result, fluctuations in the internal volume of the storage structure can be avoided. Can be suppressed. As a result, the above-mentioned effect of keeping the amount of urine in contact with the sensor electrode 20 constant and accurately and stably measuring the uric acid concentration by the unit 100 can be obtained more reliably.

(C) By arranging the sensor electrode 20 on the urine flow path from the inlet 33 to the discharge port 52, the amount of urine that comes into contact with the sensor electrode 20 can be reliably made constant. As a result, it becomes possible to measure the uric acid concentration in urine more accurately and stably.

(D) The position and size of the discharge port 52 are set so that the discharge port 52 includes all of the sensor electrodes 20 when the unit 100 is viewed from the side, and the discharge port 52 is the unit 100. By providing the sensor electrodes 20 on both sides of the base material 10 in the width direction when viewed in a plan view, the excess urine taken into the storage structure can be discharged without relying on human operation. It will be possible to do it reliably. As a result, the amount of urine that comes into contact with the sensor electrode 20 can be reliably made constant, and the uric acid concentration in urine can be measured more accurately and stably.

(E) The sheet 30 is provided with a water-repellent member 31 and a water-absorbing member 32, and the water-absorbing member 32 is provided inside the storage structure. Then, the urine absorbed by the water absorbing member 32 is brought into contact with the surface of the sensor electrode 20. As a result, urine can be reliably stored in the storage structure, and the amount of urine that comes into contact with the sensor electrode 20 can be more reliably made constant. Further, by absorbing and holding urine in the water absorbing member 32, the amount of urine in contact with the sensor electrode 20 can be surely kept constant regardless of the posture of the unit 100 when measuring the uric acid concentration. .. As a result, it becomes possible to measure the uric acid concentration by the unit 100 more accurately and stably.

(F) By adhering the peripheral edge of the sheet 30 and the left end of the base material 10 to each other, the exposure of the sensor electrode 20 due to the turning of the edge of the sheet 30 is avoided, and the sensitivity of the sensor electrode 20 is lowered due to sebum stains. It is possible to avoid situations such as damage.

(G) By making the discharge port 52 a simple structure in which a part of the peripheral edge of the sheet 30 and the base material 10 are not adhered to each other instead of a check valve, the unit 100 is complicated, upsized, and high. It is possible to avoid costing.

(4) Modification example This embodiment can be modified as the following modification example. Further, these modified examples can be arbitrarily combined.

(Modification 1)
In the above aspect, an example in which the peripheral edge portion of the sheet 30 and the base material 10 are adhered to each other via an adhesive 51 or the like has been described, but the present disclosure is not limited to such an aspect. For example, as shown in FIG. 5, the sheet 30 and the base material 10 may be adhered to each other via an adhesive 51 or the like. For example, in FIG. 5, when the vertical and horizontal directions of the paper surface are defined as the vertical and horizontal directions when the unit 100 is viewed in a plan view, the peripheral edge of the sheet 30 and the left side of the base material 10 (the side on which the sensor electrode 20 is provided). ) The end portions may be adhered to each other via the adhesive 51 or the like, and the sheet 30 and the central portion of the base material 10 may be adhered to each other via the adhesive 51 or the like. The same effect as the above-described embodiment can be obtained by this modification as well. Further, in this modification, since the sheet 30 and the central portion of the base material 10 are adhered to each other, the urine taken into the storage structure from the intake 33 is convex according to the posture of the unit 100. It is also possible to prevent the flow to the portion 12 side. As a result, the adhesion of urine to the wirings 13 to 15 can be reliably avoided, and the uric acid concentration can be measured more accurately and stably. In addition, the infiltration of urine into the measuring instrument can be reliably avoided, and the malfunction or damage of the measuring instrument can be avoided.

(Modification 2)
Further, for example, the discharge port 52 may be provided on either side in the width direction of the base material 10 with the sensor electrode 20 interposed therebetween when the unit 100 is viewed in a plan view. Also in this modification, the same effect as the above-mentioned aspect can be obtained. However, as in the above aspect, when the discharge port 52 is provided on both sides of the base material 10 in the width direction with the sensor electrode 20 interposed therebetween, the excess urine taken into the storage structure is artificially discharged. It is preferable in that it can be performed more reliably without relying on a specific operation.

(Modification 3)
Further, for example, the discharge port 52 is a position facing the sensor electrode 20 when the unit 100 is viewed in a plan view, and is located on one end side (the side where the sensor electrode 20 is provided) in the longitudinal direction of the base material 10. It may be provided. That is, it may be provided at the left end portion of the base material 10. Also in this modification, the same effect as the above-mentioned aspect can be obtained.

(Modification example 4)
Further, for example, the discharge port 52 is provided on at least one side in the width direction of the base material 10 and the left end portion of the base material 10 with the sensor electrode 20 interposed therebetween when the unit 100 is viewed in a plan view. May be. Also in this modification, the same effect as the above-mentioned aspect can be obtained.

(Modification 5)
Further, for example, the discharge port 52 may be configured by a notch provided in the sheet 30 (water repellent member 31) constituting the storage structure. The notch may be provided at a position where a part of the urine taken into the storage structure from the intake 33 can be discharged. For example, the notch can be provided in a part of the peripheral portion of the sheet 30. Further, it is preferable that the notch is provided at at least one position in the width direction of the base material 10 and / or at the left end portion of the base material 10. Also in this modification, the same effect as the above-mentioned aspect can be obtained.

(Modification 6)
Further, for example, the discharge port 52 may be configured by providing a through hole in the base material 10. In this case, it is preferable that a through hole is provided in the base material 10 at a position where the sensor electrode 20 is not provided. Also in this modified example, substantially the same effect as the above-mentioned aspect can be obtained.

(Modification 7)
Further, for example, the sheet 30 does not have to have the water absorbing member 32. That is, the sheet 30 may be composed of the water-repellent member 31 in which the intake 33 is opened, and may be configured so that the urine taken in from the intake 33 comes into direct contact with the surface of the sensor electrode 20. Also in this modified example, substantially the same effect as the above-mentioned aspect can be obtained. However, as in the above aspect, if the urine supplied to the unit 100 is configured to come into contact with the surface of the sensor electrode 20 via the water absorbing member 32, the urine that comes into contact with the surface of the sensor electrode 20 It is preferable in that the amount can be ensured to a constant amount and the uric acid concentration in urine can be measured accurately and stably.

(Modification 8)
In the above aspect, an example in which the working electrode 21 and the wiring 13 are integrally formed, the counter electrode 22 and the wiring 14 are integrally formed, and the reference electrode 23 and the wiring 15 are integrally formed has been described. , The present disclosure is not limited to such aspects. The working electrode 21 may be formed separately from the wiring 13, and the working electrode 21 and the wiring 13 may be connected via a conductive adhesive. Similarly, the counter electrode 22 may be formed separately from the wiring 14, the counter electrode 22 and the wiring 14 may be connected via a conductive adhesive, and the reference electrode 23 may be formed separately from the wiring 15. , The reference electrode 23 and the wiring 15 may be connected via conductivity.

<Other aspects of the present disclosure>
The embodiment of the present disclosure has been specifically described above. However, the present disclosure is not limited to the above-described embodiment, and various changes can be made without departing from the gist thereof.

In the above aspect, an example in which the liquid test sample is urine collected from a subject has been described, but the present disclosure is not limited to such an aspect. For example, the liquid test sample may be body fluid such as saliva, runny nose, sweat, tears, and blood, in addition to urine. Further, in the above aspect, an example in which the specific component contained in the test sample is uric acid has been described, but the present disclosure is not limited to such an aspect. For example, the specific component contained in the test sample may be uric acid, urinary sugar, sodium, potassium, nitrite, arginine, albumin, creatinine and the like. Further, the liquid test sample is not limited to that derived from humans, and may be derived from animals such as dogs and cats, for example.

In the above aspect, an example in which the subject supplies urine to the unit 100 by pouring urine toward the intake 33 of the unit 100 has been described, but the present invention is not limited to this. For example, the test sample is supplied to the unit 100 by immersing the side of the unit 100 in which the sensor electrode 20 is provided in a container or the like containing the test sample, and the test sample is taken into the storage structure from the intake 33. May be good. In this case, it is preferable to use a flexible substrate as the base material 10. As a result, the base material 10 can be easily bent. As a result, for example, even when the amount of the test sample in the container is small, the test sample can be easily taken in from the intake 33 by bending the base material 10.

In the above aspect, an example of measuring the concentration of a specific component in a test sample by a three-electrode method has been described, but the present disclosure is not limited to such an aspect. For example, the concentration of a specific component in a test sample may be measured by a two-electrode method. In this case, the sensor electrode 20 may have two electrodes, a working electrode 21 and a counter electrode 22 (or a reference electrode 23).

In the above aspect, an example in which one sensor electrode 20 is provided on the upper surface of the base material 10 has been described, but the present disclosure is not limited to such an aspect. A plurality of (two or more) sensor electrodes 20 may be provided on the upper surface of the base material 10. In this case, it becomes possible to measure the concentration of a plurality of types of specific components in urine. For example, it is possible to measure the uric acid concentration in urine and the concentration of a specific component (for example, urinary sugar) different from uric acid in urine with one unit 100.

This aspect also has substantially the same effect as the above-mentioned aspect. It should be noted that this aspect can be carried out in any form in combination with the various aspects and modifications described above.

<Preferable aspect of the present disclosure>
Hereinafter, preferred embodiments of the present disclosure will be described.

(Appendix 1)
According to one aspect of the present disclosure
With the base material
A sensor electrode provided on one of the two main surfaces of the base material, and
An intake capable of taking in a liquid test sample is opened, and a sheet provided on one surface of the substrate so as to cover the sensor electrode is provided.
A storage structure is configured in which the peripheral edge of the sheet and the base material are adhered to each other to store the test sample taken in from the intake and bring it into contact with the sensor electrode.
The storage structure provides an electrochemical sensor unit having a discharge port for discharging a part of a test sample taken in through the intake. The discharge port functions to adjust the amount of the test sample in contact with the sensor electrode by discharging a part of the test sample.

(Appendix 2)
The sensor unit according to Appendix 1, preferably.
The discharge port is configured such that a part of the peripheral portion of the sheet is non-adhesive to the base material.

(Appendix 3)
The sensor unit according to

Appendix

1 or 2, preferably.
The discharge port is configured by a notch provided in a part of the peripheral portion of the sheet.

(Appendix 4)
The sensor unit according to any one of Supplementary note 1 to 3, preferably.
The sensor electrode is arranged on the flow path of the test sample from the inlet to the outlet.

(Appendix 5)
The sensor unit according to any one of Supplementary note 1 to 4, preferably.
The discharge port is provided at a position overlapping with at least a part of the sensor electrode when the sensor unit is viewed from the side.

(Appendix 6)
The sensor unit according to Appendix 5, preferably.
The base material has a longitudinal shape and has a longitudinal shape.
The discharge port is provided on at least one side in a direction orthogonal to the longitudinal direction of the base material.

(Appendix 7)
The sensor unit according to Appendix 5, preferably.
The base material has a longitudinal shape and has a longitudinal shape.
The discharge ports are provided at positions on both sides in a direction orthogonal to the longitudinal direction of the base material.

(Appendix 8)
The sensor unit according to any one of Supplementary note 5 to 8, preferably.
The base material has a longitudinal shape and has a longitudinal shape.
The sensor electrode is provided on one end side in the longitudinal direction of the base material.
The discharge port is provided on the one end side of the base material.

(Appendix 9)
The sensor unit according to any one of Supplementary note 1 to 8, preferably.
The outlet has a size that overlaps with at least a part of the sensor electrode when the sensor unit is viewed from the side.

(Appendix 10)
The sensor unit according to any one of Supplementary note 1 to 9, preferably.
The sheet has a water-repellent member that does not absorb the test sample, and a water-absorbing member that is provided so as to close the intake and absorbs the test sample.
The water absorbing member is arranged so as to cover at least a part of the sensor electrode.
The test sample taken in from the intake is absorbed by the water absorbing member and permeates to the surface of the sensor electrode so that the test sample is brought into contact with the sensor electrode, and the test sample not absorbed by the water absorbing member is discharged. It is configured to be discharged from the outlet.

(Appendix 11)
The sensor unit according to Appendix 10, preferably.
The water absorbing member is provided on the back surface side of the water repellent member.

100 Electrochemical sensor unit 10 Base material 20 Sensor electrode 30 Sheet 33 Inlet 52 Outlet

Claims

With the base material
A sensor electrode provided on one of the two main surfaces of the base material, and
An intake capable of taking in a liquid test sample is opened, and a sheet provided on one surface of the substrate so as to cover the sensor electrode is provided.
A storage structure is configured in which the peripheral edge of the sheet and the base material are adhered to each other to store the test sample taken in from the intake and bring it into contact with the sensor electrode.
The storage structure is an electrochemical sensor unit having an outlet for discharging a part of a test sample taken in through the intake.
The electrochemical sensor unit according to claim 1, wherein the discharge port is configured such that a part of the peripheral portion of the sheet is non-adhesive to the base material.
The electrochemical sensor unit according to claim 1 or 2, wherein the discharge port is formed by a notch provided in a part of the peripheral portion of the sheet.
The electrochemical sensor unit according to any one of claims 1 to 3, wherein the sensor electrode is arranged on a flow path of a test sample from the intake port to the discharge port.
The electrochemical sensor unit according to any one of claims 1 to 4, wherein the discharge port is provided at a position overlapping with at least a part of the sensor electrode when the sensor unit is viewed from the side.
The base material has a longitudinal shape and has a longitudinal shape.
The electrochemical sensor unit according to claim 5, wherein the discharge port is provided on at least one side in a direction orthogonal to the longitudinal direction of the base material.
The base material has a longitudinal shape and has a longitudinal shape.
The electrochemical sensor unit according to claim 5, wherein the discharge ports are provided on both sides in a direction orthogonal to the longitudinal direction of the base material.
The base material has a longitudinal shape and has a longitudinal shape.
The sensor electrode is provided on one end side in the longitudinal direction of the base material.
The electrochemical sensor unit according to any one of claims 5 to 7, wherein the discharge port is provided on one end side of the base material.
The electrochemical sensor unit according to any one of claims 1 to 8, wherein the outlet has a size that overlaps with at least a part of the sensor electrode when the sensor unit is viewed from the side.
The sheet has a water-repellent member that does not absorb the test sample, and a water-absorbing member that is provided so as to close the intake and absorbs the test sample.
The water absorbing member is arranged so as to cover at least a part of the sensor electrode.
The test sample taken in from the intake is absorbed by the water absorbing member and permeates to the surface of the sensor electrode to bring the test sample into contact with the sensor electrode, and the test sample not absorbed by the water absorbing member is discharged. The electrochemical sensor unit according to any one of claims 1 to 9, which is configured to be discharged from an outlet.