Electrochemical sensor unit

Abstract

To provide a technique for performing efficient and accurate detection of specific component in test target liquid when electrochemically detecting it.SOLUTION: An electrochemical sensor unit 1 is composed by combining a plurality of electrochemical sensors 10. At least one of the plurality of electrochemical sensors 10 comprises: a plate-like member 11 having a first face and a second face which are in front-to-rear relation, and a supply flow passage 11a for test target liquid formed on the first face; and a liquid reservoir path 15 which is disposed on the second face side of the plate-like member 11 and into which part of the test target liquid flowing over a downstream side end 11c of the plate-like member 11 with the supply flow passage 11a formed thereon flows. In plan view of the plate-like member 11, a liquid collecting port 15a serving as inlet of the liquid reservoir path 15 is positioned away from the downstream side end 11c toward the upstream side of the supply flow passage 11a.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to an electrochemical sensor unit.

Background Art

[0002] In recent years, for the diagnosis and prevention of diseases of a subject, etc., detecting a specific component in a test liquid such as urine with an electrochemical sensor and measuring a concentration value is performed (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Component detection using an electrochemical sensor is desirably performed efficiently in any case. For example, when it is necessary to detect a plurality of types of specific components contained in a test liquid, it cannot necessarily be said that it is efficient to repeatedly perform individual detections for each component type. Further, component detection using an electrochemical sensor is performed by bringing a test liquid into contact with a sensor electrode in the electrochemical sensor, but even when aiming for efficiency, it is necessary to avoid the contact amount of the test liquid with the sensor electrode not being guaranteed and having an adverse effect on the detection accuracy.

[0005] The present disclosure provides a technique that enables efficient and accurate detection when electrochemically detecting a specific component in a test liquid.

Means for Solving the Problems

[0006] According to one aspect of the present disclosure, an electrochemical sensor unit configured by combining a plurality of electrochemical sensors, At least one of the aforementioned electrochemical sensors is A plate-shaped member having a first surface and a second surface that are in a front-back relationship, with a supply channel for the test liquid formed on the side of the first surface, The plate-shaped member comprises a liquid storage passage located on the second surface side of the plate-shaped member, into which a portion of the liquid to be tested flows after passing the downstream end of the plate-shaped member where the supply channel is formed, In a plan view of the plate-shaped member, the liquid collection port, which serves as the entrance to the liquid storage channel, is located away from the downstream end and upstream of the supply channel. An electrochemical sensor unit is provided. [Effects of the Invention]

[0007] According to this disclosure, it becomes possible to efficiently and accurately detect specific components in a test solution using electrochemical methods. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic exploded perspective view showing an example configuration of an electrochemical sensor according to the first embodiment of this disclosure. [Figure 2] This is a schematic side cross-sectional view showing an example of processing operation in a key part of an electrochemical sensor according to the first embodiment of this disclosure. [Figure 3] This is a partially enlarged view showing an example of the main components of an electrochemical sensor according to the first embodiment of this disclosure. [Figure 4] This is a schematic diagram illustrating a general configuration example of an electrochemical sensor unit according to the first embodiment of this disclosure. [Figure 5] This is a schematic diagram illustrating another example of the main component configuration at the downstream end of the test solution in the electrochemical sensor unit according to the first embodiment of this disclosure. [Figure 6] This is a schematic explanatory diagram (part 1) showing an example of the main components of the upstream end of the test solution in the electrochemical sensor unit according to the first embodiment of this disclosure. [Figure 7] This is a schematic explanatory diagram (part 2) showing an example of the main components of the upstream end of the test solution in the electrochemical sensor unit according to the first embodiment of this disclosure. [Figure 8] It is an explanatory diagram schematically showing a schematic configuration example of an electrochemical sensor unit according to a second embodiment of the present disclosure. [Figure 9] It is an explanatory diagram schematically showing an example of a main part configuration of an upstream end of a test solution in an electrochemical sensor unit according to a second embodiment of the present disclosure. [Figure 10] It is an explanatory diagram showing a modified example of an electrochemical sensor according to the present disclosure.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] (1) Relationship between Electrochemical Sensor Unit and Electrochemical Sensor First, the relationship between the electrochemical sensor unit and the electrochemical sensor will be briefly described.

[0011] The electrical sensor unit is configured by combining a plurality of electrochemical sensors (hereinafter sometimes referred to as "sensor modules"). That is, one sensor unit is configured by combining a plurality of sensor modules.

[0012] Each of the plurality of electrochemical sensors constituting the electrical sensor unit electrochemically detects a specific component in the test solution. Note that each electrochemical sensor can use those having the same configuration.

[0013] Hereinafter, the electrical sensor unit and the electrochemical sensors constituting the electrical sensor unit will be specifically described by taking the first embodiment and the second embodiment as examples.

[0014] (2) First Embodiment Here, prior to the description of the electrical sensor unit, the electrochemical sensors constituting the electrical sensor unit will be described.

[0015] (Outline of Electrochemical Sensor) As described above, an electrochemical sensor electrochemically detects a specific component in a test solution. In this embodiment, urine collected from a subject is exemplified as the test solution. Further, examples of the specific component to be detected include creatinine, ketone bodies, uric acid, glucose, albumin, etc. contained in urine.

[0016] The electrochemical detection by the electrochemical sensor means detecting by using an electrochemical reaction (for example, redox reaction) that occurs when a substance contained in urine as the test solution is electrolyzed under specific conditions. In this embodiment, the case of detecting the concentration of a specific component in urine by the three-electrode method is taken as an example. The three-electrode method is a technique for performing electrochemical measurement by combining three electrodes: a working electrode, a counter electrode, and a reference electrode.

[0017] When detecting a specific component in urine, the electrochemical sensor is used with one end thereof inserted into the insertion port (slot) of the measuring instrument. The measuring instrument is, for example, a device called a potentiostat, and is configured to be able to perform a predetermined voltage sweep operation while being electrically connected to each electrode of the electrochemical sensor inserted into the insertion port. For this purpose, the measuring instrument has, for example, a voltage application unit, a current measurement unit, a potential difference measurement unit, and a potential adjustment unit. The voltage application unit is configured to apply a voltage between the working electrode and the counter electrode in the electrochemical sensor when a predetermined circuit is formed by connection with the electrochemical sensor. The current measurement unit is configured to measure the current generated by the redox reaction of the specific component in urine. The potential difference measurement unit is configured to measure the potential difference between the working electrode and the reference electrode. The potential adjustment unit is configured to keep the potential of the working electrode constant based on the potential difference measured by the potential difference measurement unit with reference to the potential of the reference electrode.

[0018] In the state of being inserted into the insertion port of such a measuring instrument, urine flowing by the urination of the subject is directly supplied to the electrochemical sensor. As a result, in the electrochemical sensor, at least the vicinity of the end portion on the side opposite to the insertion end to the measuring instrument comes into contact with the flow of urine as the test solution.

[0019] When the electrochemical sensor comes into contact with the flow of urine, it uses capillary action to collect a portion of the flowing urine. The electrochemical sensor then brings the collected urine into contact with three electrodes (i.e., the working electrode, the counter electrode, and the reference electrode). This makes it possible to detect the concentration of specific components in the collected urine using the three-electrode method.

[0020] (Example of an electrochemical sensor configuration) Here, we will specifically describe an example of the configuration of the electrochemical sensor according to this embodiment. Here, we will focus on one of the multiple electrochemical sensors constituting the electrochemical sensor unit and describe an example of the configuration of that single electrochemical sensor, but it will be assumed that the other electrochemical sensors have a similar configuration.

[0021] Figure 1 is a schematic exploded perspective view showing an example of the configuration of the electrochemical sensor 10 according to this embodiment. For convenience, the components are shown separated in the figure.

[0022] The electrochemical sensor 10 according to this embodiment comprises a protective cover member 11, a flow path cover member 12, a spacer member 13, and a base material 14, which are stacked together.

[0023] The protective cover member 11 is intended to cover and protect each electrode 14a, 14b, and 14c on the base material 14, which will be described later, and is formed of a plate-like member having a first surface (e.g., front surface) and a second surface (e.g., back surface) that are in a front-back relationship. When urine, which is the test fluid, is supplied to the electrochemical sensor 10 (see arrow B in the figure), the supplied urine flows along the first surface of the protective cover member 11, thereby forming a urine supply channel 11a on the side of the first surface. The protective cover member 11 is made of a water-resistant material, specifically a resin material, ceramic, glass, paper, etc., preferably a resin material such as polyethylene (PE) or polyethylene terephthalate (PET). If it is made of a resin material such as PE or PET, the thickness of the protective cover member 11 should be about 0.1 to 0.6 mm. The protective cover member 11 is provided with a through hole 11b that penetrates in the thickness direction of the protective cover member 11, near the end 11c opposite to the insertion end when inserting the electrochemical sensor 10 into the insertion port of the measuring instrument (i.e., the downstream end of the supply channel 11a). The planar shape of the through hole 11b is not particularly limited.

[0024] The flow path cover member 12 is positioned in contact with the second surface of the protective cover member 11 and constitutes a part of the wall surface of the liquid storage passage 15, which will be described later. The flow path cover member 12 is also provided with a slit groove 12a for forming a ventilation passage connected to the liquid storage passage 15. The ventilation passage formed by the slit groove 12a has an end opposite to the liquid storage passage 15 that is open to the atmosphere. The flow path cover member 12 is formed from the same material as the protective cover member 11. The flow path cover member 12 is stacked on the protective cover member 11 such that, in a plan view, the downstream end 12b of the flow in the supply flow path 11a is located upstream of the downstream end 11c of the protective cover member 11 by a predetermined distance (see arrow C in the figure). The predetermined distance will be described in detail later.

[0025] The spacer member 13 is positioned between the flow path cover member 12 and the base material 14, and is intended to form a liquid storage passage 15, which will be described later. For this purpose, the spacer member 13 is provided with a notch 13a for forming the liquid storage passage 15. The spacer member 13 is formed from the same material as the protective cover member 11 and the flow path cover member 12. Furthermore, similar to the flow path cover member 12, the spacer member 13 is stacked on the flow path cover member 12 such that its downstream end 13b in the supply flow path 11a is located at a predetermined distance (see arrow C in the figure) upstream of the supply flow path 11a in a plan view, compared to the position of the downstream end 11c of the protective cover member 11.

[0026] The base material 14 supports the working electrode 14a, counter electrode 14b, and reference electrode 14c for detection using the three-electrode method. The electrodes 14a, 14b, and 14c are mounted in the vicinity of the downstream end 14e of the supply channel 11a, and the end opposite to the end 14e is configured to be the insertion end for the measuring instrument. The base material 14 is also provided with wiring 14d for individually connecting each electrode 14a, 14b, and 14c to the measuring instrument. As the working electrode 14a, for example, a chip-shaped electrode (diamond tip electrode) having a diamond film that generates an oxidation-reduction reaction according to the applied voltage when urine is attached can be used. As the counter electrode 14b, for example, an electrode made of a metal such as platinum (Pt), gold (Au), copper (Cu), palladium (Pd), nickel (Ni), or silver (Ag), a diamond electrode, a boron-doped diamond (BDD) electrode, or a carbon electrode can be used. As the reference electrode 14c, for example, a silver / silver chloride (Ag / AgCl) electrode, a standard hydrogen electrode, a reversible hydrogen electrode, a palladium-hydrogen electrode, a saturated calomel electrode, a carbon electrode, a diamond electrode, or an electrode made of a metal such as Pt, Au, Cu, Pd, Ni, or Ag can be used. Each of these electrodes 14a, 14b, 14c and the wiring 14d can be constructed using known techniques, and a detailed explanation thereof is omitted here. The base material 14 is formed from the same material as the protective cover member 11, the flow path cover member 12, and the spacer member 13. Furthermore, similar to the flow path cover member 12 and the spacer member 13, the base material 14 is laminated to the spacer member 13 such that the downstream end 14e of the supply flow path 11a is located at a predetermined distance (see arrow C in the figure) upstream of the supply flow path 11a from the position of the downstream end 11c of the protective cover member 11 in a plan view.

[0027] When the protective cover member 11, flow path cover member 12, spacer member 13, and base material 14 are stacked as described above, the notch 13a of the spacer member 13 is sandwiched between the flow path cover member 12 and the base material 14 on the second surface side of the protective cover member 11, thereby forming a space enclosed on all four sides. This space constitutes the liquid storage passage 15.

[0028] The liquid storage channel 15 is configured to store a certain amount of urine within its space. The urine supplied to the supply channel 11a of the protective cover member 11 (see arrow B in the figure) has some of it flow over the downstream end 11c of the protective cover member 11 and into the liquid storage channel 15 (see arrow D in the figure). Specifically, with urine whose flow velocity and flow shape fluctuate, a few seconds of urine application can cause several μL or more of urine to flow over the downstream end 11c. As this urine flows in, the space of the liquid storage channel 15 is filled with urine, and the liquid storage channel 15 stores a certain amount of urine. The urine flowing into the liquid storage channel 15 may include urine that has passed through the through-hole 11b of the protective cover member 11.

[0029] In the liquid storage passage 15, electrodes 14a, 14b, and 14c are positioned on the base material 14 so as to face the space that will become the liquid storage passage 15. As a result, when urine flows into the liquid storage passage 15 and is stored there, electrodes 14a, 14b, and 14c come into contact with the urine.

[0030] The flow of urine into the liquid storage passage 15 is induced by capillary action. Therefore, the size of the liquid storage passage 15 (such as the width of the notch 13a and the thickness of the spacer member 13) is formed to induce capillary action. Furthermore, in order to induce capillary action, the slit groove 12a of the flow path cover member 12 is connected to the liquid storage passage 15, thereby forming an air passage (i.e., an airway) connected to the liquid storage passage 15. Specifically, regarding the size of the liquid storage passage 15, for example, if the width of the notch 13a is about 1 to 7 mm and the thickness of the spacer member 13 is about 0.1 to 0.6 mm, it is possible to induce capillary action.

[0031] Furthermore, urine flows into the liquid storage channel 15 through the liquid collection port 15a, which serves as the entrance to the liquid storage channel 15. The liquid collection port 15a is located at the boundary between the inside and outside of the space that forms the liquid storage channel 15, and is formed by the end 12b of the flow path cover member 12, the end 13b of the spacer member 13, and the end 14e of the base material 14. In other words, the liquid collection port 15a is formed so that it is surrounded on all four sides by the edges of the flow path cover member 12, the spacer member 13, and the base material 14. Here, we have given an example where the positions of the ends 12b, 13b, and 14e are aligned, and the liquid collection port 15a is formed in a rectangular shape surrounded on all four sides, but it is not necessarily limited to this. That is, the liquid collection port 15a does not necessarily have to be rectangular as long as it is located at the boundary between the inside and outside of the space, and may be formed in a circular shape, for example. Furthermore, the positions of all ends 12b, 13b, and 14e do not necessarily have to be aligned. In that case, a space that becomes the liquid storage passage 15 is formed by being surrounded on at least three sides. The boundary between the inside and outside of this space is defined by the positions of the ends that surround it on three sides, and the liquid collection port 15a is located at that boundary.

[0032] The end 12b of the flow channel cover member 12, the end 13b of the spacer member 13, and the end 14e of the base material 14 that form the liquid collection port 15a are all located at a predetermined distance (see arrow C in the figure) upstream of the supply flow channel 11a from the position of the downstream end 11c of the protective cover member 11 in a plan view. Therefore, the liquid collection port 15a is also located at a predetermined distance (see arrow C in the figure) upstream of the supply flow channel 11a from the downstream end 11c of the protective cover member 11 in a plan view. The predetermined distance will be described in detail later.

[0033] Furthermore, it is preferable that the walls constituting the liquid storage passage 15, that is, the surfaces of the flow path cover member 12, spacer member 13, and base material 14 surrounding the space that becomes the liquid storage passage 15, are hydrophilic treated surfaces in order to facilitate the flow of urine into the liquid storage passage 15. A hydrophilic treated surface is a surface that has been treated to improve its affinity for liquids (e.g., water) (i.e., hydrophilicity or wettability). Treatment to improve hydrophilicity can be carried out using known techniques such as plasma treatment, and a detailed explanation thereof is omitted here. While it is preferable that all surfaces of the walls constituting the liquid storage passage 15 be hydrophilic, this is not necessarily the case; it is sufficient if at least one surface of the walls constituting the liquid storage passage 15 is hydrophilic. Even in this case, urine is more likely to flow into the liquid storage passage 15 compared to the case where there are no hydrophilic surfaces at all. Hydrophilic treated surfaces may be located not only on the wall surfaces constituting the liquid storage channel 15, but also on surfaces other than the wall surfaces. Specifically, the exposed portion of the second surface of the protective cover member 11 (the portion not covered by the flow channel cover member 12, etc.), the end face constituting the downstream end 11c of the protective cover member 11, the end face constituting the downstream end 12b of the flow channel cover member 12, the end face constituting the downstream end 13b of the spacer member 13, and the end face constituting the downstream end 14e of the base material 14 may be hydrophilic treated surfaces. If these surfaces are hydrophilic treated surfaces, urine will be able to reach the liquid collection port 15a of the liquid storage channel 15 more easily from the supply channel 11a.

[0034] (Example of processing operation in an electrochemical sensor) Next, we will describe an example of the processing operation of the electrochemical sensor 10 configured according to this embodiment as described above. Here, as in the description of the configuration example above, we will focus on one electrochemical sensor 10 and describe an example of the basic processing operation of that electrochemical sensor 10.

[0035] Figure 2 is a schematic side cross-sectional view showing an example of processing operation in the main part of the electrochemical sensor 10 according to this embodiment.

[0036] When detecting the concentration of a specific component in a subject's urine using the electrochemical sensor 10 according to this embodiment, first, the electrochemical sensor 10 is connected to a measuring device. Then, while the subject holds the measuring device, the electrochemical sensor 10, which is connected to the measuring device, is brought into contact with the urine flowing from the subject during urination. As a result, a urine supply channel 11a is formed on the first surface side of the protective cover member 11 of the electrochemical sensor 10.

[0037] Once the urine supply channel 11a is formed, some of the urine that passes over the downstream end 11c of the protective cover member 11 flows around to the second surface of the protective cover member 11 and reaches the collection port 15a of the liquid storage channel 15. The urine that reaches the collection port 15a then flows into the space of the liquid storage channel 15 by capillary action and fills that space. As a result, a certain amount of urine is stored in the liquid storage channel 15, and this state is maintained by balancing it with the atmospheric pressure from the ventilation channel through the slit groove 12a.

[0038] In this case, if the protective cover member 11 is provided with a through hole 11b, the urine that passes through the through hole 11b will also reach the liquid collection port 15a and flow into the liquid storage channel 15. Therefore, the urine flowing through the supply channel 11a will flow more easily into the liquid storage channel 15.

[0039] Furthermore, if the walls constituting the liquid storage passage 15 are hydrophilic treated surfaces, the resistance to urine flowing into the liquid storage passage 15 can be reduced, making it easier for urine to flow into the liquid storage passage 15.

[0040] Furthermore, although a ventilation passage formed by a slit groove 12a is connected to the liquid storage passage 15 into which urine flows, this ventilation passage is covered by a protective cover member 11, so urine cannot flow into the liquid storage passage 15 from the ventilation passage side. In other words, the ventilation passage is protected by the protective cover member 11, which allows a constant amount of urine to be stored in the liquid storage passage 15.

[0041] When the liquid storage channel 15 stores a certain amount of urine, the working electrode 14a, counter electrode 14b, and reference electrode 14c on the substrate 14 come into contact with the urine within the liquid storage channel 15. In this state, a predetermined voltage is applied from the measuring instrument between the working electrode 14a and the counter electrode 14b. This causes an oxidation-reduction reaction of a specific component in the urine (e.g., uric acid) to occur at the working electrode 14a, and an electric current (reaction current) flows through the working electrode 14a. The value of this reaction current is measured using the current measuring unit of the measuring instrument, for example, by cyclic voltammetry. The value of the reaction current may also be measured using methods such as square wave voltammetry, differential pulse voltammetry, normal pulse voltammetry, or AC voltammetry. In addition, while the urine is in contact, the potential difference (voltage difference) between the working electrode 14a and the reference electrode 14c is measured using the potential difference measuring unit of the measuring instrument.

[0042] Subsequently, a cyclic voltammogram is created, for example, from the reaction current value measured by the current measuring unit of the measuring instrument, and the current value of the oxidation peak is obtained. Then, the concentration of the specific component in the urine is calculated (quantified) based on the obtained oxidation peak current value and the potential difference value measured by the potential difference measuring unit of the measuring instrument. It has been disclosed in public literature (e.g., Analysts, 2018.10, 991-996, see Figures 3 and 4) that the reaction current value is correlated with the concentration of the specific component in the urine (e.g., uric acid). Therefore, if the relationship between the reaction current value and the concentration of the specific component is determined in advance, the concentration of the specific component in the urine can be quantified based on the measured reaction current value.

[0043] By following the procedure described above, it becomes possible to detect the concentration of specific components in urine (creatinine, ketones, uric acid, glucose, albumin, etc.) by electrochemical measurement, even when the urine sample is supplied in a flowing state.

[0044] Incidentally, urination from a subject typically continues for a certain period of time. Therefore, even after the liquid storage channel 15 has stored a certain amount of urine, urine flow may continue in the supply channel 11a on the protective cover member 11.

[0045] In that case, since the urine flowing through the supply channel 11a and the urine stored in the liquid storage channel 15 are the same liquid, the liquid molecules attract each other through intermolecular forces, and an attractive force can be generated due to the affinity between the two identical liquids. In other words, if the flow of urine continues in the supply channel 11a, that flow of urine can exert an attractive force on the urine stored in the liquid storage channel 15.

[0046] Therefore, as shown in the reference example in Figure 2(b), if the position of the downstream end 11c of the protective cover member 11 and the position of the liquid collection port 15a of the liquid storage passage 15 coincide in a plan view of the protective cover member 11, there is a risk that the urine in the liquid storage passage 15 may be drawn out by the suction force acting on the urine flow in the supply passage 11a (see arrow E in the figure). If the urine in the liquid storage passage 15 is drawn out, the amount of urine in contact with each electrode 14a, 14b, and 14c on the base material 14 cannot be guaranteed, and there are concerns that this may adversely affect the sensing results using each electrode 14a, 14b, and 14c.

[0047] In contrast, in the electrochemical sensor 10 according to this embodiment, as shown in Figure 2(a), the liquid collection port 15a of the liquid storage passage 15 is located a predetermined distance (see arrow C in the figure) upstream of the supply passage 11a from the downstream end 11c of the protective cover member 11. In other words, from the perspective of the liquid collection port 15a of the liquid storage passage 15, the flow of urine in the supply passage 11a is blocked by the amount that the downstream end 11c of the protective cover member 11 protrudes downstream of the supply passage 11a. Therefore, even if urine flows into the liquid storage passage 15 and the liquid storage passage 15 is storing urine, and there is a flow of urine in the supply passage 11a (see arrow B in the figure), the suction force on the urine in the liquid storage passage 15 caused by the urine flow can be weakened by the amount that the liquid collection port 15a is separated from the downstream end 11c (see dashed arrow E in the figure). Therefore, the electrochemical sensor 10 according to this embodiment can prevent urine from being drawn out of the liquid storage passage 15 by the flow of urine in the supply passage 11a.

[0048] The predetermined distance between the downstream end 11c and the liquid collection port 15a (i.e., the amount of protrusion of the downstream end 11c as seen from the liquid collection port 15a) is set as described below. The distance between the downstream end 11c and the liquid collection port 15a is set to a distance that allows urine that has passed the downstream end 11c to wrap around and reach the liquid collection port 15a. Specifically, the distance that allows urine to reach the liquid collection port 15a should be set considering the surface tension of the urine and the wettability of the second surface of the protective cover member 11. Furthermore, the distance between the downstream end 11c and the liquid collection port 15a is set to a distance that can weaken the suction force on the urine in the liquid storage channel 15 due to the urine flow in the supply channel 11a. Specifically, the distance should be set to a distance that can weaken the suction force by considering the urine flow velocity and surface tension of the urine in the supply channel 11a. More specifically, this distance is such that the relationship holds: the holding force of the urine in the liquid storage channel 15 > the suction force on the urine in the liquid storage channel 15. In other words, the distance between the downstream end 11c and the liquid collection port 15a is set such that when there is no urine in the liquid storage passage 15, urine will flow back into the liquid collection port 15a, and when there is urine in the liquid storage passage 15, the suction force caused by the urine flowing through the supply channel 11a is weakened. A specific example of such a distance (protrusion amount) is, for example, 0.3 to 1.5 mm, preferably 0.5 to 1.0 mm, and more preferably 0.6 to 0.8 mm, if the test fluid is urine excreted from the human body.

[0049] If the protective cover member 11 is provided with a through hole 11b, the distance between the downstream end 11c and the liquid collection port 15a may be set while taking into account the diameter of the through hole 11b. However, even if a through-hole 11b is provided, the area of ​​the protective cover member 11 for blocking the flow of urine in the supply channel 11a shall be secured. Figure 3 is a partially enlarged view showing an example of the main components of the electrochemical sensor according to this embodiment. Specifically, as shown in Figure 3(a), even when a through-hole 11b is provided, at least one of the following regions of the protective cover member 11 functions to block the flow of urine in the supply channel 11a: the region between the end 13b of the spacer member 13 and the upstream end of the through-hole 11b, the region between the downstream end of the through-hole 11b and the downstream end 11c of the protective cover member 11, and the regions located on both sides of the through-hole 11b when viewed from the direction of urine flow in the liquid storage channel 15. Therefore, even when a through-hole 11b is provided, the protective cover member 11 can reduce the suction force on the urine in the liquid storage channel 15. Furthermore, as shown in Figure 3(b), the protective cover member 11 may have a notch 11d instead of a through hole 11b. Even when a notch 11d is provided, just as with the case of a through hole 11b, the urine flowing through the supply channel 11a flows more easily into the liquid storage channel 15, and the area that blocks the flow of urine in the supply channel 11a weakens the suction force on the urine in the liquid storage channel 15.

[0050] As described above, the electrochemical sensor 10 according to this embodiment can prevent urine in the liquid storage passage 15 from being sucked out by the urine flow in the supply passage 11a due to the positional relationship between the downstream end 11c of the protective cover member 11 and the liquid collection port 15a of the liquid storage passage 15. As a result, even when urine is supplied in a flowing state, the liquid storage passage 15 can maintain a state in which it stores a certain amount of urine, thereby ensuring that the amount of urine in contact with each electrode 14a, 14b, and 14c on the substrate 14 is guaranteed.

[0051] The electrochemical sensor 10 described above produces one or more of the following effects.

[0052] (a) In the electrochemical sensor 10, when urine, which is the test fluid, is supplied to the first side of the protective cover member 11, a supply channel 11a is formed on the first side, and the supplied urine flows through the supply channel 11a. A portion of the urine flowing through the supply channel 11a then flows around to the second side of the protective cover member 11 and flows into the liquid storage channel 15 from the liquid collection port 15a using capillary action, and is stored in the liquid storage channel 15. Therefore, when the electrodes 14a, 14b, and 14c on the base material 14 come into contact with the urine stored in the liquid storage channel 15, it becomes possible to detect the concentration of specific components in the urine even when the urine, which is the test fluid, is supplied in a flowing state.

[0053] Furthermore, in the electrochemical sensor 10, the liquid collection port 15a of the liquid storage channel 15 is located upstream of the supply channel 11a, away from the downstream end 11c of the protective cover member 11. Therefore, even if urine flows in the supply channel 11a while the liquid storage channel 15 is storing urine, the distance between the downstream end 11c and the liquid collection port 15a weakens the suction force on the urine in the liquid storage channel 15 caused by the urine flow. This prevents the urine in the liquid storage channel 15 from being sucked out by the urine flow in the supply channel 11a. Consequently, even when urine is supplied with a flow, the liquid storage channel 15 can maintain a state of storing a certain amount of urine, ensuring that the amount of urine contacts each electrode 14a, 14b, and 14c on the substrate 14 is guaranteed, and enabling accurate detection of the concentration of specific components in the urine using each electrode 14a, 14b, and 14c.

[0054] (b) In the electrochemical sensor 10, by providing a through hole 11b or a notch 11d in the protective cover member 11, the urine flowing through the supply channel 11a can easily flow into the liquid storage channel 15. In other words, even if the downstream end 11c of the protective cover member 11 protrudes from the liquid collection port 15a of the liquid storage channel 15, by using the through hole 11b to facilitate the flow of urine into the liquid storage channel 15, it becomes possible to easily and reliably achieve a state in which the liquid storage channel 15 stores a certain amount of urine.

[0055] (c) In the electrochemical sensor 10, by making the wall surface constituting the liquid storage passage 15 a hydrophilic surface, the resistance when urine flows into the liquid storage passage 15 can be reduced compared to when the surface is not hydrophilic. Therefore, it becomes easier to cause urine to flow into the liquid storage passage 15, thereby making it easy and reliable to achieve a state in which the liquid storage passage 15 stores a certain amount of urine.

[0056] (d) In the electrochemical sensor 10, the slit groove 12a provided in the flow path cover member 12 constitutes a ventilation passage connected to the liquid storage passage 15, thereby allowing urine to flow from the liquid collection port 15a into the liquid storage passage 15, and a certain amount of urine to be stored in the liquid storage passage 15. However, the ventilation passage is covered and protected by the protective cover member 11. Therefore, urine cannot flow into the liquid storage passage 15 from the ventilation passage side, and a certain amount of urine can be reliably maintained in the liquid storage passage 15.

[0057] (Example configuration of an electrochemical sensor unit) Next, we will describe an electrical sensor unit that includes the electrochemical sensor 10 described above.

[0058] As described above, the electrochemical sensor 10 makes it possible to accurately detect the concentration of specific components in the urine of a subject. However, urine contains multiple types of specific components, such as creatinine, ketones, uric acid, glucose, and albumin. When it is necessary to detect these multiple types of specific components, it is not necessarily efficient to prepare an electrochemical sensor 10 for each type of component and repeatedly perform individual detection using each electrochemical sensor 10. Therefore, in this embodiment, an electrical sensor unit is constructed by combining multiple electrochemical sensors 10.

[0059] Figure 4 is a schematic diagram illustrating an example of the general configuration of the electrochemical sensor unit 1 according to this embodiment.

[0060] The electrochemical sensor unit 1 according to this embodiment is composed of a combination of multiple (for example, three) electrochemical sensors 10. The number of electrochemical sensors 10 to be combined is not particularly limited and can be set as appropriate. For example, the number of electrochemical sensors 10 can be set according to the number of types of specific components to be detected.

[0061] Each electrochemical sensor 10 is configured similarly. That is, each electrochemical sensor 10 comprises a protective cover member 11 as a plate-shaped member, a flow path cover member 12, a spacer member 13, and a base material 14 that constitute the liquid storage passage 15. In each electrochemical sensor 10, the liquid collection port 15a of the liquid storage passage 15 is located a predetermined distance (see arrow C in the figure) upstream of the supply flow path 11a from the downstream end 11c of the protective cover member 11. Here, we give an example where all of the electrochemical sensors 10 have the same configuration, but the system is not necessarily limited to this. It is sufficient that at least one of the electrochemical sensors 10 is configured such that the liquid collection port 15a of the liquid storage passage 15 is located away from the downstream end 11c of the protective cover member 11.

[0062] In this embodiment, each of these electrochemical sensors 10 is combined in a stacked structure. A stacked structure, as used here, refers to a structure in which multiple electrochemical sensors 10 are arranged to be stacked along the direction in which the constituent members 11 to 14 of the electrochemical sensor 10 are stacked. In such a stacked structure, it is preferable that the contact surfaces of each electrochemical sensor 10 are sealed by adhesive in the area where each electrochemical sensor 10 overlaps due to stacking (area F in the figure) so that excess urine does not enter between them.

[0063] Furthermore, when each electrochemical sensor 10 having a similar configuration is combined in a stacked structure, each electrochemical sensor 10 should be positioned such that the downstream end 11c of the protective cover member 11 of each sensor is aligned in a plan view of the protective cover member 11. In that case, the downstream end 11c of each electrochemical sensor 10 will be aligned in the same position in the flow direction of the supply channel 11a (see arrow B in the figure).

[0064] In this way, by configuring the stacked structure so that the downstream ends 11c of each electrochemical sensor 10 are aligned, the positional relationship between the downstream end 11c and the liquid collection port 15a of the liquid storage passage 15 becomes the same for each electrochemical sensor 10. Therefore, even when each electrochemical sensor 10 is combined in a stacked structure, urine can be stored in the liquid storage passage 15 under the same conditions for each electrochemical sensor 10, and the suction force on the urine in the liquid storage passage 15 can be suppressed under the same conditions. In other words, even with a stacked structure, the function of the tip structure of each electrochemical sensor 10 is not impaired.

[0065] However, the arrangement of each electrochemical sensor 10 constituting the stacked structure is not limited to this example. Figure 5 is a schematic diagram illustrating another example of the main components of the downstream end of the test solution in the electrochemical sensor unit 1 according to this embodiment. As shown in the example figure, when several electrochemical sensors 10 having similar configurations are combined in a stacked structure, each electrochemical sensor 10 may be positioned such that the downstream end 11c of the protective cover member 11 in each sensor is located upstream of the supply channel 11a in the flow direction (see arrow B in the figure) as it moves towards the lower layers of the stacked structure (i.e., as it moves further away from the supply channel 11a). In this case, the downstream end 11c of each electrochemical sensor 10 will be located a predetermined distance (see arrow G in the figure) upstream of the supply channel 11a relative to the electrochemical sensor 10 directly above it.

[0066] Thus, by configuring the stacked structure such that the downstream end 11c of each electrochemical sensor 10 is located further upstream of the supply channel 11a as it is positioned in the lower layers, it becomes possible to differentiate the conditions for storing urine in the liquid storage channel 15 and the conditions for suppressing the suction force on the urine in the liquid storage channel 15 between the upper and lower layers of the stacked structure. Specifically, for example, it becomes possible to increase the shielding effect on the flow of urine in the supply channel 11a (the effect of weakening the suction force on the urine in the liquid storage channel 15) as it is positioned in the lower layers of the stacked structure. Therefore, when each electrochemical sensor 10 is combined in a stacked structure, the functions of the tip structure of each electrochemical sensor 10 can be effectively utilized according to its position in the stacked structure.

[0067] As described above, in the stacked structure, in both cases where the downstream end 11c of each electrochemical sensor 10 is aligned (see Figure 4) and where the downstream end 11c is located further upstream of the supply channel 11a as it is on the lower layer side (see Figure 5), it is preferable that the side of the insertion end into the insertion port of the measuring instrument is configured as follows.

[0068] Figures 6 and 7 are schematic explanatory diagrams illustrating an example of the main components of the upstream end of the test solution in the electrochemical sensor unit 1 according to this embodiment.

[0069] As shown in Figure 6, each electrochemical sensor 10 constituting the stacked structure is equipped with a base material 14. Sensor electrodes 14a, 14b, and 14c are arranged on one end of each base material 14, and contact terminals 14f are arranged on the other end, which are individually electrically connected to each sensor electrode 14a, 14b, and 14c via wiring 14d. In other words, on the side of each electrochemical sensor 10 that is inserted into the insertion port of the measuring instrument, the contact terminals 14f are arranged on the base material 14.

[0070] Furthermore, the base material 14 of each electrochemical sensor 10 is arranged such that the edge on the side where the contact terminal 14f is located forms a stepped structure. The stepped structure referred to here means a structure in which multiple electrochemical sensors 10 are stacked on top of each other, in which the contact terminal 14f is exposed without being covered by the protective cover member 11, the flow path cover member 12, and the spacer member 13, and furthermore, the edge of the base material 14 is located on the upstream side in the flow direction of the supply flow path 11a as the lower layer of the stacked structure approaches.

[0071] Thus, if the edges of the base material 14 on the side of the contact terminals 14f are arranged to form a stepped structure, even if each electrochemical sensor 10 forms a stacked structure, exposure of the contact terminals 14f on the base material 14 is ensured for each electrochemical sensor 10, and the space above each contact terminal 14f is not covered by other components. Therefore, it becomes easy to ensure reliable conductivity to each contact terminal 14f when inserting it into the insertion slot of the measuring instrument.

[0072] Furthermore, as shown in Figures 6 and 7, a space is provided around the location of the contact terminal 14f on each substrate 14 of each electrochemical sensor 10 for a liquid ingress prevention member 22 that is positioned to surround that location.

[0073] More specifically, as shown in Figure 7(a), when the insertion end of the electrochemical sensor 10 is inserted into the insertion port of the measuring instrument, the contact terminal 14f on the base material 14 of the electrochemical sensor 10 comes into contact with the connecting terminal 21 of the measuring instrument, thereby ensuring electrical connection with the measuring instrument. In order to enable the liquid ingress prevention member 22 to be positioned around the location of the contact terminal 14f, the area around the location of the contact terminal 14f on the base material 14 is formed as a flat surface with nothing provided except for the wiring 14d that ensures electrical connection with electrodes 14a, 14b, and 14c. In other words, as shown in Figures 7(a) and (b), the area around the location of the contact terminal 14f on the base material 14 is free of other components except for the wiring 14d, thereby securing space for the liquid ingress prevention member 22.

[0074] As shown in Figures 7(a) and (c), the liquid ingress prevention member 22 is installed on the side of the measuring instrument so as to surround the location of the connection terminal 21 provided on the measuring instrument. However, it is not limited to this, and the liquid ingress prevention member 22 only needs to be installed on at least one of the sides of the measuring instrument and on the base material 14 of the electrochemical sensor 10.

[0075] For example, adhesive tape material or insulating resin material can be used as the liquid ingress prevention member 22. However, it is not necessarily limited to these, and any material having insulating or liquid-resistant properties may be used to construct the member.

[0076] Thus, if space is secured around the contact terminal 14f for the liquid ingress prevention member 22, when the contact terminal 14f and the mating terminal 21 are brought into contact, it is possible to prevent urine from entering the space in which they exist (i.e., the space surrounded by the liquid ingress prevention member 22). Therefore, when electrical conductivity with the measuring instrument is secured by inserting the instrument into its insertion port, even if urine enters the insertion port, it is possible to effectively prevent urine from entering the connection point between the contact terminal 14f and the mating terminal 21, thereby preventing electrical short circuits and other problems caused by urine ingress.

[0077] (Example of processing operation in an electrochemical sensor unit) Next, an example of the processing operation of the electrochemical sensor unit 1 according to this embodiment, configured as described above, will be explained.

[0078] When detecting the concentration of a specific component in a subject's urine using the electrochemical sensor unit 1 according to this embodiment, first, the electrochemical sensor unit 1, in which each electrochemical sensor 10 is integrated by a stacked structure, is connected to a measuring instrument. Then, while the subject holds the measuring instrument, the electrochemical sensor unit 1, which is connected to the measuring instrument, is brought into contact with the urine flowing from the subject's urination. As a result, a urine supply channel 11a is formed on the first surface side of the protective cover member 11 for the electrochemical sensor 10 located in the uppermost layer of the stacked structure among the electrochemical sensors 10 constituting the electrochemical sensor unit 1. At this time, if each electrochemical sensor 10 is integrated by a stacked structure, it is sufficient to form the supply channel 11a in the uppermost layer of the stacked structure, and the area required for forming the supply channel 11a can be relatively small. Therefore, it is very suitable for forming the supply channel 11a by urination from the subject and is easy for the subject to use.

[0079] When the urine supply channel 11a is formed, some of the urine flows to the lower layer of the stacked structure. As a result, a certain amount of urine is stored in the liquid storage channels 15 of each electrochemical sensor 10 that constitutes the stacked structure. Furthermore, even if there is a flow of urine in the supply channel 11a while the liquid storage channels 15 are storing urine, the suction force on the urine in the liquid storage channels 15 is suppressed, thus maintaining the urine storage state in the liquid storage channels 15.

[0080] In each electrochemical sensor 10, when a certain amount of urine is stored in the respective liquid reservoir 15, the electrodes 14a, 14b, and 14c on the substrate 14 come into contact with the urine. Therefore, the measuring instrument can use each of the electrochemical sensors 10 and determine the value of the reaction current in each using methods such as cyclic voltammetry, square wave voltammetry, differential pulse voltammetry, normal pulse voltammetry, and AC voltammetry, and then quantify the concentration of a specific component in the urine based on the value of the reaction current.

[0081] In this case, the measuring instrument may apply different conditions (for example, calibration curves individually set for each type of specific component) to the reaction current values ​​from each electrochemical sensor 10 to quantify the component concentration. In this way, it becomes possible to electrochemically detect multiple types of specific components in the urine flowing through the supply channel 11a in parallel using each electrochemical sensor 10. Specifically, for example, it becomes possible to quantify the concentration of creatinine contained in the urine flowing through the supply channel 11a using one electrochemical sensor 10, quantify the concentration of uric acid contained in the urine using another electrochemical sensor 10, and further quantify the concentration of albumin contained in the urine using yet another electrochemical sensor 10.

[0082] In other words, since the electrochemical sensor unit 1 is composed of multiple electrochemical sensors 10, by utilizing each electrochemical sensor 10, electrochemical detection of multiple specific components in urine can be performed in parallel. Therefore, even when it is necessary to detect multiple specific components in urine, there is no need to repeatedly perform individual detection for each component, and the detection can be performed very efficiently with a single urine sample. Furthermore, since multiple specific components can be detected with a single urine sample, it is extremely convenient for subjects providing urine samples.

[0083] Furthermore, each electrochemical sensor 10 constituting the electrochemical sensor unit 1 is configured such that the suction force on the urine in each liquid storage channel 15 is suppressed even when urine is flowing in the supply channel 11a. Therefore, even when urine is supplied in a flowing state, each liquid storage channel 15 can maintain a state of storing a certain amount of urine, thereby ensuring the amount of urine in contact with the electrodes 14a, 14b, and 14c on the substrate 14, and enabling accurate detection of specific components in the urine using each electrode 14a, 14b, and 14c.

[0084] As described above, the electrochemical sensor unit 1 according to this embodiment makes it possible to efficiently and accurately detect multiple types of specific components contained in urine using electrochemical methods.

[0085] In the above description, the example given was the detection of multiple specific components contained in urine using each electrochemical sensor 10 constituting the electrochemical sensor unit 1, but the invention is not necessarily limited to this. For example, each electrochemical sensor 10 constituting the electrochemical sensor unit 1 may be used to detect the same specific component in urine in parallel. Even in this case, the detection can be performed very efficiently in response to a single urine supply. Moreover, if each electrochemical sensor 10 detects the same specific component in parallel, then, for example, by processing such as removing noise components based on the respective detection results, the influence of individual differences in electrodes 14a, 14b, and 14c in each electrochemical sensor 10 can be eliminated, thereby improving the accuracy and reliability of the detection results. In other words, according to the electrochemical sensor unit 1 of this embodiment, even when electrochemically detecting the same specific component contained in urine, it is possible to perform the detection efficiently and accurately.

[0086] (3) Second embodiment Next, a second embodiment will be described. Here, we will mainly explain the differences from the first embodiment described above, and will omit explanations of content that is the same as the first embodiment.

[0087] (Example configuration of an electrochemical sensor unit) Figure 8 is a schematic diagram illustrating an example of the general configuration of the electrochemical sensor unit 1 according to this embodiment.

[0088] The electrochemical sensor unit 1 according to this embodiment is also configured by combining a plurality (for example, three) of electrochemical sensors 10, similar to the first embodiment. Each electrochemical sensor 10 is also configured in the same way as in the first embodiment.

[0089] However, in this embodiment, unlike in the first embodiment, each electrochemical sensor 10 is arranged in parallel. Parallel arrangement here means that the ends of the electrodes 14a, 14b, and 14c of each electrochemical sensor 10 face the same direction, and the ends of each electrochemical sensor 10 that are inserted into the measuring instrument port face the same direction, so that the electrochemical sensors 10 are arranged in approximately parallel lines.

[0090] To realize such a parallel arrangement structure, the electrochemical sensor unit 1 according to this embodiment is equipped with a plate-shaped support member 16 that supports each electrochemical sensor 10. The shape and size of the support member 16 are not particularly limited as long as it has mechanical strength to support multiple electrochemical sensors 10, but considering the usability of the electrochemical sensor unit 1, it is preferable to form it in a plate shape as shown in the figure. Furthermore, the material used to form the support member 16 is not particularly limited, but like other sensor components, it can be formed from any of the following: resin material, ceramic, glass, paper, etc., preferably a resin material such as PE or PET.

[0091] In the case of a parallel arrangement structure, each electrochemical sensor 10 should be positioned such that the downstream end 11c of the protective cover member 11 of each sensor is aligned in the same position in the flow direction of the supply channel 11a (see arrow B in the figure). However, the arrangement is not necessarily limited to this, and each electrochemical sensor 10 may be arranged offset from each other so that the positions of their respective downstream ends 11c are different.

[0092] Furthermore, regarding the side of the contact terminal 14f opposite to the downstream end 11c (i.e., the end inserted into the measuring instrument's insertion port), the arrangement is not limited to a specific configuration as long as the contact terminal 14f of each electrochemical sensor 10 is exposed. In other words, in the case of a parallel arrangement structure, a stepped structure like that in the case of a stacked structure is not necessarily required.

[0093] Furthermore, the side of the measuring instrument that is inserted into the insertion port is preferably configured as follows. Figure 9 is a schematic diagram illustrating an example of the main components of the upstream end of the test solution in the electrochemical sensor unit 1 according to this embodiment. As shown in the diagram, even in the case of a parallel arrangement structure, space is secured around the location of the contact terminal 14f on each substrate 14 of each electrochemical sensor 10 for the placement of a liquid ingress prevention member 22 that surrounds that location.

[0094] The liquid ingress prevention member 22 may be configured in the same manner as in the first embodiment. However, in the case of a parallel arrangement structure, instead of individually placing the liquid ingress prevention member 22 for each contact terminal 14f on the base material 14 of each electrochemical sensor 10, the liquid ingress prevention member 22 may be integrated as a continuous body, as shown in Figure 9(c). With such a configuration, it is possible to reduce the number of components while effectively preventing urine from entering the contact terminals 14f of each electrochemical sensor 10 arranged in parallel.

[0095] (Example of processing operation in an electrochemical sensor unit) Next, an example of the processing operation of the electrochemical sensor unit 1 according to this embodiment, configured as described above, will be explained.

[0096] When detecting the concentration of a specific component in a subject's urine using the electrochemical sensor unit 1 according to this embodiment, first, the electrochemical sensor unit 1, in which each electrochemical sensor 10 is integrated in a parallel arrangement structure, is connected to a measuring instrument. Then, while the subject holds the measuring instrument, each of the electrochemical sensors 10 in the electrochemical sensor unit 1, which is connected to the measuring instrument, is brought into contact with the urine flowing from the subject during urination. As a result, a urine supply channel 11a is formed on the first surface side of each protective cover member 11 of each electrochemical sensor 10 constituting the electrochemical sensor unit 1.

[0097] When the urine supply channel 11a is formed, a certain amount of urine is stored in the liquid storage channels 15 of each of the parallel-arranged electrochemical sensors 10. Even if urine flows in the supply channel 11a while the liquid storage channels 15 are storing urine, the suction force on the urine in the liquid storage channels 15 is suppressed, thus maintaining the urine storage state in the liquid storage channels 15. At this time, if each electrochemical sensor 10 is integrated by a parallel arrangement structure, the relationship (positional relationship, etc.) between the urine flowing in the supply channel 11a and the liquid storage channels 15 can be made substantially the same for each electrochemical sensor 10. Therefore, it is possible to suppress differences (variations) in the urine storage state in the liquid storage channels 15 of each electrochemical sensor 10.

[0098] In each electrochemical sensor 10, once a certain amount of urine is stored in the respective liquid storage passage 15, the electrodes 14a, 14b, and 14c on the substrate 14 come into contact with the urine. Therefore, thereafter, as in the first embodiment, the concentration of a specific component in the urine can be quantified.

[0099] In other words, the electrochemical sensor unit 1 according to this embodiment also makes it possible to efficiently and accurately detect multiple types of specific components contained in urine using electrochemical means. Furthermore, it is possible to detect the same type of specific component in urine in parallel, and in that case as well, the detection can be performed efficiently and accurately.

[0100] (4) Variations etc. Although the first and second embodiments of this disclosure have been described in detail above, this disclosure is not necessarily limited to the contents of each of the embodiments described above, and can be modified in various ways without departing from its gist.

[0101] For example, in each of the embodiments described above, the example in which the test fluid is urine was explained, but this disclosure is not limited to such embodiments. For example, the test fluid may be bodily fluids other than urine, such as blood, saliva, nasal mucus, sweat, or tears, as long as it is supplied in a flowing state. Furthermore, the test fluid is not limited to human origin, but may be derived from animals such as dogs or cats.

[0102] Furthermore, although the embodiments described above illustrate the measurement of the concentration of a specific component in a test solution using a three-electrode method, this disclosure is not limited to such embodiments. For example, the concentration of a specific substance in a test solution may be measured using a two-electrode method. In this case, the sensor electrode only needs to have two electrodes: a working electrode and a counter electrode (or reference electrode).

[0103] Furthermore, although the embodiments described above explained the case in which a voltage is applied and the concentration is measured during the continuous flow process, the present disclosure is not limited to such embodiments. For example, similar effects can be obtained even when a voltage is applied and the concentration is measured after the completion of the continuous flow process.

[0104] Furthermore, in the embodiments described above, a slit groove 12a is provided in the flow path cover member 12 for each electrochemical sensor 10 constituting the electrochemical sensor unit 1, and this is used as an example to explain the case in which a ventilation passage connected to the liquid storage passage 15 is formed. However, this disclosure is not limited to this embodiment. For example, it may be formed by a slit processed portion (not shown) formed in the spacer member 13, in which case the flow path cover member 12 is not required. Moreover, the ventilation passage connected to the liquid storage passage 15 may be formed by, for example, a groove processed portion (not shown) formed in the base material 14, or at least one of a through hole (not shown) formed in the base material 14. Even when a through hole formed in the base material 14 functions as a ventilation passage, the through hole is located on the side opposite to the urine supply flow path 11a, so the inflow of urine from the ventilation passage side is suppressed. If the inflow of urine from the ventilation channel can be suppressed, the length of the protective cover member 11 may be limited. Specifically, for example, if the flow path cover member 12 is provided with a slit groove 12a, the protective cover member 11 only needs to be long enough to protect the ventilation channel, and instead of the downstream end 11c of the protective cover member 11, the downstream end 12b of the flow path cover member 12 may be positioned to protrude beyond the spacer member 13. Even in that case, the fact that the end 12b of the flow path cover member 12 protrudes beyond the spacer member 13 allows some of the urine to be guided into the liquid storage channel 15 while weakening the suction force on the urine in the liquid storage channel 15 caused by the flow of urine. In other words, in a configuration having a protective cover member 11 and a flow path cover member 12, it becomes possible to make these laminates function as a "plate-like member," and if at least one of the respective ends 11c, 12b is located away from the liquid collection port 15a of the liquid storage channel 15, the effects described in each of the embodiments above will be achieved.

[0105] Furthermore, in the embodiments described above, examples were given in which sensor electrodes 14a, 14b, 14c, wiring 14d, and contact terminals 14f for each electrochemical sensor 10 constituting the electrochemical sensor unit 1 are provided on a single substrate 14. However, the present disclosure is not limited to such embodiments. For example, the sensor electrodes 14a, 14b, and 14c and the wiring 14d and contact terminals 14f may be formed as separate pieces, and these pieces may be ultimately combined to construct the electrochemical sensor 10 described in the embodiments above. Figure 10 is an explanatory diagram showing a modified example of the electrochemical sensor 10. Since each electrochemical sensor 10 constituting the electrochemical sensor unit 1 is used with urine flowing through it, it is preferable to ensure a certain length (for example, 100 mm or more) between the location where the urine supply channel 11a is formed and the location where it is inserted into the measuring instrument's insertion port. However, when manufacturing the sensor electrodes 14a, 14b, and 14c, a smaller area allows for a greater number of units to be produced, resulting in better efficiency. Therefore, as shown in Figure 10, the portion 14g that requires a certain length may be provided with wiring 14d and contact terminals 14f without mounting the sensor electrodes 14a, 14b, and 14c, and a separate portion 14h for mounting the sensor electrodes 14a, 14b, and 14c may be manufactured, and these may be finally combined to form the electrochemical sensor 10. This method improves the efficiency of manufacturing each electrochemical sensor 10, and is particularly effective when combining multiple electrochemical sensors 10 to form an electrochemical sensor unit 1.

[0106] Furthermore, while the embodiments described above described an electrochemical sensor 10 utilizing an electrochemical reaction (e.g., a redox reaction), it is also conceivable to apply this technology to other sensors, such as biosensors that utilize the molecular recognition ability of biomolecules, or ion sensors that utilize ion-selective membranes to measure ionic components such as sodium ions and potassium ions in urine, which is used as the test solution, as long as the test solution is supplied in a flowing state. In other words, the electrochemical sensors related to this disclosure are applicable to a wide range of fields, including the medical and drug discovery fields, the food industry, and the environmental field. Specifically, the electrochemical sensors related to this disclosure include sensors that detect specific components in bodily fluids using electrochemical reactions (e.g., oxidation-reduction reactions), biosensors that utilize the molecular recognition ability of biomolecules, and ion sensors using ion-selective membranes. By applying the characteristic configuration of this disclosure to such electrochemical sensors, it becomes possible to suppress the suction out of the stored test fluid even if there is still flow of the test fluid in contact with the sensor after the test fluid has been stored due to capillary action. [Explanation of Symbols]

[0107] 1... Electrochemical sensor unit, 10... Electrochemical sensor, 11... Protective cover member, 11a... Supply channel, 12... Channel cover member, 13... Spacer member, 14... Base material, 14a... Working electrode, 14b... Counter electrode, 14c... Reference electrode, 14d... Wiring, 14f... Contact terminal, 15... Liquid reservoir, 15a... Liquid sampling port, 16... Support member, 22... Liquid ingress prevention member

Claims

1. An electrochemical sensor unit composed of multiple electrochemical sensors, At least one of the aforementioned electrochemical sensors is A plate-shaped member having a first surface and a second surface that are in a front-back relationship, with a supply channel for the test liquid formed on the side of the first surface, A liquid storage passage is provided on the side of the second surface of the plate-shaped member, into which a portion of the liquid to be tested flows after passing the downstream end of the plate-shaped member where the supply channel is formed, The system comprises electrodes disposed within the liquid storage passage, The system is configured to detect a specific component in the test solution by having the electrode come into contact with the test solution that has flowed into the liquid reservoir. In a plan view of the plate-shaped member, the liquid collection port, which serves as the entrance to the liquid storage channel, is located away from the downstream end and upstream of the supply channel. Electrochemical sensor unit.

2. The aforementioned multiple electrochemical sensors are combined in a stacked structure. The electrochemical sensor unit according to claim 1.

3. All of the aforementioned electrochemical sensors are equipped with the plate-shaped member and the liquid storage passage. In each of the aforementioned electrochemical sensors, the liquid sampling port is located away from the downstream end and upstream of the supply channel. The downstream ends of the plate-shaped members in each of the plurality of electrochemical sensors are arranged so that they are aligned in a plan view of the plate-shaped members, or the lower layers of the laminated structure are positioned further upstream of the supply channel. The electrochemical sensor unit according to claim 2.

4. Each of the aforementioned electrochemical sensors comprises, in addition to the plate-shaped member and the liquid reservoir, a substrate on which a sensor electrode is disposed at one end and a contact terminal on the other end that is electrically connected to the sensor electrode via wiring. The base material is positioned relative to the plate-shaped member and the liquid storage passage such that the sensor electrode faces the liquid storage passage. In each of the plurality of electrochemical sensors, the substrate is arranged such that the edge on the side where the contact terminals are located forms a stepped structure. The electrochemical sensor unit according to claim 2 or 3.

5. The aforementioned multiple electrochemical sensors are arranged in parallel and combined. The electrochemical sensor unit according to claim 1.

6. Each of the aforementioned electrochemical sensors comprises, in addition to the plate-shaped member and the liquid reservoir, a substrate on which a sensor electrode is disposed at one end and a contact terminal on the other end that is electrically connected to the sensor electrode via wiring. Around the location where the contact terminals are positioned on the substrate, space is provided for a liquid ingress prevention member that is positioned to surround the location. The electrochemical sensor unit according to claim 2 or 5.

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