Electrochemical sensors

Abstract

To make a disposable portion of an electrochemical sensor usable without impairing convenience, and to minimize the amount of wiring material (metal) to reduce cost and facilitate disposal.SOLUTION: An electrochemical sensor 10 comprises: a cover member 11 that is formed into a cylindrical shape with an open end 11a at one end and a sealed end 11b at the other end; a sensor electrode 12b that has a detection surface brought into contact with liquid to be tested and is arranged so that the detection surface is exposed on a cylindrical outer face of the cover member 11; and a connection electrode 12c that is electrically connected with the detection surface and is arranged to be exposed to a cylindrical inner face of the cover member 11. In a state where a stick-like leading end 22 of a measuring instrument 20 is inserted from the opening end 11a of the cover member 11 into the inside of the cylindrical shape, a terminal part 26 formed at the stick-like leading end 22 is electrically connected with the connection electrode 12c.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electrochemical sensor for electrochemically detecting a specific component in a test solution.

Background Art

[0002] As an electrochemical sensor, there is one that is detachable from the main body part of a measuring instrument, and thus can cope with the disposable use of a used sensor. In that case, the disposable part is configured in a long stick shape so that the test solution does not touch the measuring instrument or the hand holding it, and a sensor electrode is disposed near the tip thereof (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the disposable part is configured in a long stick shape, the distance of the wiring material (metal) on the base material constituting the disposable part becomes long, and there is a concern that the cost of the disposable part increases. Considering noise countermeasures for the wiring material, there is also a risk of further cost increase. In addition, when the metal content of the disposable part is large, there is also an aspect that it is difficult to discard it as combustible waste.

[0005] The present disclosure provides a technology that enables the disposable part of an electrochemical sensor to be used without impairing convenience, and can achieve cost reduction and easy disposal by minimizing the wiring material (metal).

Means for Solving the Problems

[0006] According to one aspect of the present disclosure, A cover member formed in a cylindrical shape with one end open and the other end sealed, A sensor electrode having a detection surface that comes into contact with the test liquid, and the detection surface is arranged so as to be exposed on the outer surface of the cylinder of the cover member, It comprises a connecting electrode that is electrically connected to the detection surface and is arranged to be exposed on the inner surface of the cylinder of the cover member, With the stick-shaped tip of the measuring instrument inserted into the cylindrical interior from the open end of the cover member, the terminal portion formed on the stick-shaped tip is configured to be electrically connected to the connecting electrode. An electrochemical sensor is provided. [Effects of the Invention]

[0007] According to this disclosure, the disposable portion of the electrochemical sensor can be used without compromising convenience, and the amount of wiring material (metal) can be minimized, thereby reducing costs and facilitating disposal. [Brief explanation of the drawing]

[0008] [Figure 1] This is an explanatory diagram showing an example configuration of a detection system including an electrochemical sensor according to one embodiment of the present disclosure. [Figure 2] This is a side cross-sectional view showing an example of the main components of an electrochemical sensor according to one embodiment of the present disclosure, and is a diagram showing the cross-section AA in Figure 1. [Figure 3] This is a schematic diagram illustrating an example of the electrode configuration of an electrochemical sensor according to one embodiment of the present disclosure, and shows the view as indicated by arrow B in Figure 2. [Figure 4] This is a schematic diagram illustrating another electrode configuration example of an electrochemical sensor according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of this disclosure will be described with reference to the drawings.

[0010] (1) Overview of electrochemical sensors The electrochemical sensor described in this embodiment is for electrochemically detecting a specific component in a test solution. In this embodiment, the detection of uric acid contained in urine collected from a subject is given as an example. In other words, in this embodiment, urine collected from a subject is used as the test solution, and uric acid contained in the urine is used as the specific component to be detected.

[0011] The detection of uric acid concentration in urine is performed, for example, by electrolyzing substances contained in urine under specific conditions and utilizing the resulting electrochemical reaction (e.g., oxidation-reduction reaction). In this embodiment, the detection of uric acid concentration in urine using the three-electrode method is given as an example. The three-electrode method is a technique for performing electrochemical measurements by combining three electrodes: a working electrode, a counter electrode, and a reference electrode.

[0012] To detect uric acid concentration in urine, the electrochemical sensor is used while attached to a measuring instrument that performs the detection. In other words, the measuring instrument and the electrochemical sensor attached to it constitute a detection system for detecting uric acid concentration in urine. In this detection system, the electrochemical sensor is detachable from the main body of the measuring instrument, allowing for disposable use of the electrochemical sensor.

[0013] (2) Example of the overall system configuration Here, we will describe an example configuration of a detection system that includes an electrochemical sensor. Figure 1 is an explanatory diagram showing an example configuration of a detection system including an electrochemical sensor according to this embodiment. The detection system includes an electrochemical sensor 10, a measuring instrument 20, and a control computer (hereinafter abbreviated as "PC") (not shown). The system is configured to be used with the electrochemical sensor 10 attached to the measuring instrument 20.

[0014] (measuring instrument) The measuring instrument 20 is, for example, a potentiostat, and is configured to perform a predetermined voltage sweep operation while being electrically connected to each electrode of the electrochemical sensor 10.

[0015] Therefore, inside the main body portion of the measuring device 20, a voltage application unit, a current measurement unit, a potential difference measurement unit, and a potential adjustment unit (not shown) are provided. When a predetermined circuit is formed by connecting to the electrochemical sensor 10, the voltage application unit is configured to apply a voltage between the working electrode and the counter electrode in the electrochemical sensor 10. The current measurement unit is configured to measure the current generated by the oxidation-reduction reaction of uric acid. 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 the potential of the reference electrode as a reference.

[0016] Further, the measuring device 20 has a case portion 21 and a stick-shaped tip portion 22, and the main body portion is constituted by these.

[0017] The case portion 21 is formed so that it can be held by hand by the subject, and operation buttons 24, LED lamps 25, etc. are provided on its surface.By this, when the subject performs uric acid concentration detection, it becomes possible to operate the operation button 24 or visually recognize the LED lamp 25 while holding the case portion 21 by hand.

[0018] The stick-shaped tip portion 22 is a portion formed in a stick shape so as to extend from one end side of the case portion 21, and is a portion used for mounting the electrochemical sensor 10. And, in the stick-shaped tip portion 22, a terminal portion 26 that is connected to the voltage application unit etc. via wiring (not shown) is formed in the vicinity of its tip. Regarding the length that the stick-shaped tip portion 22 extends, it is not particularly limited. For example, when urine as the test liquid is poured on the side of the vicinity of the tip, a length that can ensure an interval (for example, 10 cm or more) such that the urine does not touch the hand etc. of the subject holding the case portion 21 can be considered. Also, it is preferable that noise countermeasures such as covering the wiring etc. in the stick-shaped tip portion 22 with a shield plate are taken.

[0019] It is assumed that the measuring instrument 20 is configured to be able to communicate with the control PC by wireless communication or wired communication.

[0020] (Control PC) The control PC receives various information transmitted from the measuring instrument 20 and performs information processing necessary for detecting the uric acid concentration in urine. Note that the information processing performed by the control PC may be performed using known techniques, and detailed description thereof is omitted here.

[0021] (Electrochemical sensor) The electrochemical sensor 10 is used to detect the uric acid concentration in urine while being attached to the stick-shaped tip portion 22 of the measuring instrument 20. For this purpose, the electrochemical sensor 10 is configured to include a cover member 11 and a printed circuit board 12.

[0022] The cover member 11 is formed in a long cylindrical shape with one end being an open end 11a and the other end being a sealed end 11b so as to correspond to the shape of the stick-shaped tip portion 22 of the measuring instrument 20, and is configured such that the stick-shaped tip portion 22 can be inserted into the cylinder from the side of the open end 11a. By inserting the stick-shaped tip portion 22 into the cylinder, the periphery of the stick-shaped tip portion 22 is covered, and thus it is configured to be attached to the stick-shaped tip portion 22. Also, the cover member 11 can be detached from the stick-shaped tip portion 22 by removing the stick-shaped tip portion from the cylinder. That is, the cover member 11 is configured to be detachable from the stick-shaped tip portion 22 of the measuring instrument 20.

[0023] In addition, an opening 11c that communicates the outer surface and the inner surface of the cylinder of the cover member 11 is provided in the vicinity of the sealed end 11b so as to correspond to the vicinity of the tip of the stick-shaped tip portion 22 (that is, the location where the terminal portion 26 is disposed). And a printed circuit board 12, the details of which will be described later, is disposed at the formation position of the opening portion 11c.

[0024] Such a cover member 11 is preferably drip-proof because urine, which is the test fluid, will be poured over it. However, the drip-proof property only needs to be sufficient to maintain drip-proofness for the duration that urine is poured over it (for example, for several tens of seconds). Furthermore, it is preferable that the cover member 11 be made of a flammable material so that it can be detached from the stick-shaped tip 22 after use as an electrochemical sensor 10 and disposed of as combustible waste. Therefore, the cover member 11 can be formed from paper such as water-resistant paper or waterproof paper. However, the material used to form the cover member 11 is not limited to paper, and may be other materials such as plastic, rubber, or silicone resin.

[0025] The printed circuit board 12 is positioned to cover the opening 11c of the cover member 11. Here, we will explain in more detail an example of the configuration of the printed circuit board 12. Figure 2 is a side cross-sectional view showing an example of the main components of the electrochemical sensor according to this embodiment, and is a diagram showing the AA cross-section in Figure 1. The printed circuit board 12 is composed of a support substrate 12a formed from a plate-shaped member of an insulating material, a sensor electrode 12b disposed on one surface of the support substrate 12a (specifically, the surface exposed to the outer surface of the cover member 11), a connecting electrode 12c disposed on the other surface of the support substrate 12a (specifically, the surface exposed to the inner surface of the cover member 11), and a via portion 12d that penetrates the support substrate 12a and makes electrical contact between the sensor electrode 12b and the connecting electrode 12c.

[0026] The support substrate 12a supports the sensor electrode 12b and the connecting electrode 12c, and has an external shape corresponding to the opening 11c of the cover member 11. The support substrate 12a is positioned to close the opening 11c of the cover member 11, and its positional relationship with the cover member 11 is fixed by the fixing device 13. For example, adhesive tape can be used as the fixing device 13. However, it is not limited to adhesive tape, and other types of fasteners 13 may be used as the fixing device 13 as long as the positional fixation between the cover member 11 and the support substrate 12a is possible. Preferably, the fixing device 13 is arranged to seal the gap between the support substrate 12a and the opening 11c of the cover member 11 over the entire outer circumference of the support substrate 12a.

[0027] The sensor electrode 12b functions as an electrode for detecting uric acid concentration in urine. To this end, the sensor electrode 12b has a detection surface that comes into contact with the urine, which is the test fluid, and is positioned so that this detection surface is exposed on the outer surface of the cover member 11. When detecting uric acid concentration in urine using the three-electrode method, the sensor electrode 12b is composed of three electrodes: an working electrode, a counter electrode, and a reference electrode. As the working electrode, for example, a tip-shaped electrode (diamond tip electrode) having a diamond film that generates an oxidation-reduction reaction in accordance with the applied voltage when urine is attached to it can be used. In this case, the diamond tip electrode has a diamond film and a support member that supports the diamond film, and the detection surface is formed by the diamond film. As counter electrodes, for example, electrodes made of metals such as platinum (Pt), gold (Au), copper (Cu), palladium (Pd), nickel (Ni), and silver (Ag), as well as diamond electrodes, boron-doped diamond (BDD) electrodes, and carbon electrodes can be used. As reference electrodes, for example, silver / silver chloride (Ag / AgCl) electrodes, standard hydrogen electrodes, reversible hydrogen electrodes, palladium-hydrogen electrodes, saturated calomel electrodes, carbon electrodes, diamond electrodes, electrodes made of metals such as Pt, Au, Cu, Pd, Ni, and Ag can be used. Each of these electrodes can be constructed using known techniques, and a detailed explanation of them is omitted here.

[0028] The connecting electrode 12c functions as an electrode for establishing a connection with the terminal portion 26 on the stick-shaped tip portion 22 of the measuring instrument 20. For this purpose, the connecting electrode 12c is electrically connected to the sensor electrode 12b via the via portion 12d, and is positioned so as to be exposed on the side opposite to the support substrate 12a from the sensor electrode 12b, i.e., on the inner surface side of the cover member 11. If the detection of uric acid concentration in urine is performed by the three-electrode method, the connecting electrode 12c shall be formed to correspond individually to the working electrode, counter electrode, and reference electrode. The same applies to the via portion 12d.

[0029] A leaf spring structure 27 is provided on at least one of the connecting electrode 12c and the terminal portion 26 of the stick-shaped tip portion 22 to ensure connection between them. In the illustrated example, the leaf spring structure 27 is shown on the terminal portion 26 side, but the leaf spring structure 27 may also be provided on the connecting electrode 12c side, or both the terminal portion 26 and the connecting electrode 12c may be provided with the leaf spring structure 27.

[0030] The leaf spring structure 27, for example, if it is provided on the terminal portion 26 side, has a leaf spring-like portion that protrudes from the stick-shaped tip portion 22 toward the connecting electrode 12c side, and elastically deforms toward the stick-shaped tip portion 22 side when an external force is applied to the protruding portion. The leaf spring-like portion is conductive and is configured to function as part of the terminal portion 26 on the stick-shaped tip portion 22, or to be electrically connected to the terminal portion 26. If the connecting electrode 12c is formed to correspond individually to the working electrode, counter electrode, and reference electrode, then the leaf spring structure 27 is also formed to correspond individually to each of them.

[0031] Here, we will explain in more detail, with specific examples, the arrangement of each electrode when the sensor electrode 12b corresponds to the three-electrode method (i.e., when the sensor electrode 12b is composed of three electrodes: a working electrode, a counter electrode, and a reference electrode). Figure 3 is a schematic diagram illustrating an example of the electrode configuration of the electrochemical sensor according to this embodiment, and shows the view as indicated by arrow B in Figure 2. As shown in the diagram, the working electrode 12b-1, the counter electrode 12b-2, and the reference electrode 12b-3, which constitute the sensor electrode 12b, are arranged in a line on the surface of the support substrate 12a that makes up the printed circuit board 12. The support substrate 12a that supports the working electrode 12b-1, the counter electrode 12b-2, and the reference electrode 12b-3 is attached to the opening 11c of the cover member 11 by the fixing device 13. As a result, the working electrode 12b-1, the counter electrode 12b-2, and the reference electrode 12b-3, which constitute the sensor electrode 12b, are mounted on the cover member 11 in a state where they are exposed on the outer surface of the cover member 11.

[0032] The arrangement of the working electrode 12b-1, counter electrode 12b-2, and reference electrode 12b-3 is not necessarily limited to the configuration shown in Figure 3, as long as they are exposed on the outer surface of the cover member 11. For example, another configuration is shown in Figure 4. Figure 4 is a schematic diagram illustrating another example of electrode configuration of the electrochemical sensor according to this embodiment. The illustrated example shows a case where the working electrode 12b-1 is a diamond tip electrode. That is, the working electrode 12b-1, counter electrode 12b-2, and reference electrode 12b-3, all diamond tip electrodes, are arranged on the surface of the support substrate 12a. The support substrate 12a is attached to a cover member (not shown) by a fixing device 13. The fixing device 13 has at least two openings 13a and 13b, through which a portion of the detection surface of the working electrode 12b-1 is exposed, and through the other opening 13b, the counter electrode 12b-2 and reference electrode 12b-3 are exposed.

[0033] (3) Examples of use of electrochemical sensors Next, we will describe an example of how to use the electrochemical sensor 10 in the detection system described above when detecting uric acid contained in urine collected from a subject.

[0034] To use the electrochemical sensor 10, first, as shown by the arrow in Figure 1, insert the stick-shaped tip 22 of the measuring instrument 20 into the cylinder of the cover member 11 that constitutes the electrochemical sensor 10. Insertion into the cylinder should continue until the tip of the stick-shaped tip 22 abuts against the innermost part of the cover member 11's cylinder. Then, maintain the state in which the cover member 11 abuts against the innermost part of the cover member 11's cylinder, that is, the state in which the cover member 11 is attached to the stick-shaped tip 22 so as to surround the stick-shaped tip 22. Hereinafter, this state will be referred to as the attached state of the cover member 11.

[0035] When the cover member 11 is attached, as shown in Figure 2, the terminal portion 26 of the stick-shaped tip 22 is positioned opposite the printed circuit board 12, which is positioned to close the opening 11c of the cover member 11. More specifically, the connecting electrode 12c on the printed circuit board 12 and the terminal portion 26 on the stick-shaped tip 22 are positioned opposite each other, and a connection between them is established via the leaf spring structure 27. At this time, by utilizing the protruding portion of the leaf spring structure 27 and its elastic deformation, the connecting electrode 12c and the terminal portion 26 can be reliably connected (physical contact) simply by inserting the stick-shaped tip 22 into a predetermined position inside the cylinder of the cover member 11 (specifically, the position where the tip of the stick-shaped tip 22 abuts against the innermost part inside the cylinder of the cover member 11). Furthermore, by utilizing the leaf spring structure 27, even if there is ample clearance in the size of the inside of the cover member 11 relative to the outer shape of the stick-shaped tip 22, the connection between the connecting electrode 12c and the terminal portion 26 can be established. As a result, insertion and removal of the stick-shaped tip 22 from the inside of the cover member 11 becomes easier.

[0036] Once the connection between the connecting electrode 12c and the terminal portion 26 is established, the terminal portion 26 becomes electrically connected to the sensor electrode 12b via the connecting electrode 12c and the via portion 12d. In other words, when the cover member 11 is attached, the sensor electrode 12b automatically becomes electrically connected to the terminal portion 26 on the stick-shaped tip portion 22.

[0037] Then, with the cover member 11 attached, when the operation button 24 of the measuring instrument 20 is operated, the measuring instrument 20 is powered on and starts up, and the electrochemical sensor 10 becomes usable. In other words, the electrochemical sensor 10 becomes usable when the stick-shaped tip 22 of the measuring instrument 20 is inserted into the cylinder of the cover member 11 and the measuring instrument 20 is powered on.

[0038] Subsequently, while the subject holds the case portion 21 of the measuring device 20, the electrochemical sensor 10 attached to the stick-shaped tip portion 22 of the measuring device 20 is brought into contact with the urine flowing from the subject as a result of urination. More specifically, the outer surface of the cover member 11 attached to the stick-shaped tip portion 22, particularly the area near the sealing end 11b of the cover member 11, including the location where the opening 11c is formed, is brought into contact with the urine from the subject.

[0039] In this case, if the extension length of the stick-shaped tip portion 22 is sufficiently secured (for example, if a distance of 10 cm or more is secured), even if urine from the subject is poured over the area near the sealing end 11b of the cover member 11, it is possible to avoid the urine coming into contact with the subject's hand or other parts holding the case portion 21. Furthermore, if the cover member 11 is drip-proof, even if urine is poured over its outer surface, it is possible to suppress the entry of urine into the cylinder of the cover member 11. Moreover, if the fixing device 13 that secures the support substrate 12a to the cover member 11 is arranged to seal the gap between the support substrate 12a and the opening 11c, the entry of urine from this gap can also be suppressed. As a result, it is possible to maintain the attached state of the cover member 11 and to avoid the entry of urine into the cylinder adversely affecting the uric acid concentration detection results described later.

[0040] When the outer surface of the cover member 11 is brought into contact with the urine in this manner, the sensor electrodes 12b (i.e., the working electrode 12b-1, the counter electrode 12b-2, and the reference electrode 12b-3) on the support substrate 12a, which are exposed through the opening 11c of the cover member 11, come into contact with the urine.

[0041] In this state, a predetermined voltage is applied from the measuring instrument 20 between the working electrode 12b-1 and the counter electrode 12b-2 via an electrical connection with the terminal portion 26 of the stick-shaped tip portion 22. This causes an oxidation-reduction reaction of uric acid to occur in the working electrode 12b-1, and an electric current (reaction current) flows through the working electrode 12b-1. The value of this reaction current is measured using the current measuring section of the measuring instrument 20, 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. Furthermore, with urine in contact, the potential difference (voltage difference) between the working electrode 12b-1 and the reference electrode 12b-3 is measured using the potential difference measuring section of the measuring instrument 20.

[0042] The measurement results of the reaction current and potential difference are then sent to the control PC via wireless or wired communication from the measuring instrument 20. The control PC creates, for example, a cyclic voltammogram from the reaction current value measured by the current measuring unit of the measuring instrument 20 and obtains the current value of the oxidation peak. Then, based on the obtained oxidation peak current value and the potential difference value measured by the potential difference measuring unit of the measuring instrument 20, the uric acid concentration in the urine is calculated (quantified). The correlation between the reaction current value and uric acid concentration has been disclosed in public literature (e.g., Analyst Methods, 2018.10, 991-996, see Figures 3 and 4). Therefore, if the relationship between the reaction current value and uric acid concentration is determined in advance, the uric acid concentration can be quantified based on the measured reaction current value.

[0043] By following these steps, it becomes possible to detect the uric acid concentration in urine flowing from a subject through electrochemical measurement using the electrochemical sensor 10. In other words, the electrochemical sensor 10 works by bringing the urine, which is the test fluid, into contact with the outer surface of the cover member 11, thereby bringing the detection surface, such as the working electrode 12b-1, exposed on the outer surface of the cylinder into contact with the urine. The reaction of the detection surface that occurs upon contact with the urine (specifically, the value of the reaction current, potential difference, etc.) is then provided to the measuring instrument 20, enabling the detection of the uric acid concentration in the urine.

[0044] As described above, the electrochemical sensor 10 can be used to detect uric acid concentration in urine by inserting the stick-shaped tip 22 of the measuring instrument 20 into the cylinder of the cover member 11 and attaching the cover member 11 to the stick-shaped tip 22. Therefore, for subjects using the electrochemical sensor 10, it is extremely convenient because uric acid concentration in urine can be detected simply by attaching the cover member 11, without requiring any other complicated procedures. In other words, subjects can use the electrochemical sensor 10 without compromising convenience.

[0045] After detecting the uric acid concentration in the urine, the electrochemical sensor 10 used for the detection is discarded. More specifically, the stick-shaped tip 22 of the measuring instrument 20 is removed from the cylindrical part of the cover member 11 that constitutes the used electrochemical sensor 10, thereby detaching the electrochemical sensor 10 from the stick-shaped tip 22, and the electrochemical sensor 10 after detachment is discarded. In this way, because the cover member 11 is detachable from the stick-shaped tip 22 of the measuring instrument 20, the electrochemical sensor 10 can be treated as disposable.

[0046] When disposing of a used electrochemical sensor 10, if the cover member 11 constituting the electrochemical sensor 10 is made of a flammable material, it is suitable for disposing of the electrochemical sensor 10 as combustible waste.

[0047] Furthermore, in the electrochemical sensor 10, the sensor electrode 12b and the connecting electrode 12c are positioned on the front and back surfaces of the support substrate 12a. Therefore, the distance of the via portion 12d that connects the sensor electrode 12b and the connecting electrode 12c does not become long, and can be kept to the minimum necessary distance. In addition, there is no need to attach metal members to the cover member 11 and printed circuit board 12 that constitute the electrochemical sensor 10, other than the sensor electrode 12b, the connecting electrode 12c, and related components such as the via portion 12d and the leaf spring structure 27. In other words, the cover member 11 and the printed circuit board 12 do not need to have metal members attached, except for the sensor electrode 12b, the connecting electrode 12c, and related components. In particular, it is preferable that the cover member 11, which has a larger surface area than the printed circuit board 12, does not have metal members attached. From the above, the electrochemical sensor 10 can reduce the cost of disposable parts by minimizing the amount of metal members that are attached. Furthermore, by minimizing the metal content in the disposable parts, the product becomes more suitable for disposal as combustible waste.

[0048] Furthermore, while it is preferable for the cover member 11 constituting the electrochemical sensor 10 to have drip-proof properties to suppress the ingress of urine into the cylinder, it is sufficient if it can maintain drip-proof properties for the duration that urine is being poured over it (for example, for several tens of seconds). Therefore, it is possible to use paper such as water-resistant paper or waterproof paper as the forming material without requiring excessive drip-proof properties, and as a result, it is possible to suppress the increase in cost of disposable parts due to the need for drip-proof properties.

[0049] Furthermore, as mentioned above, the disposable electrochemical sensor 10 has its attached metal components kept to a minimum. On the other hand, it is preferable to ensure a sufficient extension length (for example, 10 cm or more) for the stick-shaped tip 22 of the measuring instrument 20, and accordingly, it is preferable to implement noise countermeasures for the wiring, etc., of the stick-shaped tip 22. However, even if such noise countermeasures incur costs, the measuring instrument 20 including the stick-shaped tip 22 is not a disposable part, so the operating costs of the detection system including the disposable electrochemical sensor 10 can be reduced.

[0050] (4) Effects of this embodiment According to this embodiment, one or more of the following effects are achieved.

[0051] (a) In this embodiment, the electrochemical sensor 10 is configured such that, with the stick-shaped tip 22 of the measuring instrument 20 inserted into the cylinder of the cover member 11, the terminal portion 26 formed on the stick-shaped tip 22 is electrically connected to the sensor electrode 12b, which is positioned to be exposed on the outer surface of the cylinder of the cover member 11, via the connecting electrode 12c and the via portion 12d. In other words, when the cover member 11 of the electrochemical sensor 10 is attached to the stick-shaped tip 22 of the measuring instrument 20, the sensor electrode 12b and the terminal portion 26 are electrically connected accordingly, making the electrochemical sensor 10 usable for detecting uric acid concentration in urine. Therefore, according to this embodiment, by attaching the cover member 11, uric acid concentration in urine can be detected without requiring any other complicated work, making it extremely convenient for subjects using the electrochemical sensor 10.

[0052] Furthermore, in this embodiment, the electrochemical sensor 10 is designed to be disposable because the cover member 11 is detachable from the stick-shaped tip 22 of the measuring instrument 20. When disposing of the used electrochemical sensor 10 while maintaining its disposability, the sensor electrode 12b and connecting electrode 12c are positioned on the front and back surfaces of the support substrate 12a, thus minimizing the amount of metal components attached to the electrochemical sensor 10. As a result, cost reductions in the disposable portion are achieved. Moreover, minimizing the metal content of the disposable portion makes it suitable for disposal as combustible waste.

[0053] In other words, according to this embodiment, the disposable portion of the electrochemical sensor 10 can be used without compromising convenience, and moreover, it is possible to reduce costs and simplify disposal by minimizing the amount of wiring material (metal).

[0054] (b) In this embodiment, the electrochemical sensor 10 is configured to detect the uric acid concentration in the urine by bringing the detection surface of the sensor electrode 12b exposed on the outer surface of the cover member 11 into contact with the urine when the urine is brought into contact with the outer surface of the cover member 11, and by providing the reaction of the detection surface that occurs when it comes into contact with the urine (specifically, the value of the reaction current, the potential difference, etc.) to the measuring instrument 20. Therefore, according to this embodiment, the uric acid concentration in the urine can be detected by flowing urine towards the sensor electrode 12b exposed on the outer surface of the cover member 11, which is extremely convenient for the subject. Moreover, specific components in the test fluid, such as the detected uric acid concentration, are often used as indicators that are useful for maintaining the health of the subject, and by making such indicators easily and simply detectable, it is extremely beneficial for the subject.

[0055] (c) As described in this embodiment, if the working electrode in the sensor electrode 12b is a diamond tip electrode, it becomes possible to detect specific components in the test solution (for example, uric acid in urine) with high sensitivity by oxidation-reduction reactions while utilizing a diamond film that exhibits physically and chemically stable properties.

[0056] (d) As described in this embodiment, if the cover member 11 is drip-proof, even if urine is poured onto the outer surface of the cover member 11, it is possible to suppress the intrusion of urine into the cylinder of the cover member 11. Therefore, it is possible to avoid adverse effects on the detection results of specific components in the test fluid (for example, uric acid in urine) due to the intrusion of urine into the cylinder of the cover member 11.

[0057] (e) As described in this embodiment, if the cover member 11 is made of a flammable material, it is suitable for disposing of the used electrochemical sensor 10 as combustible waste when the electrochemical sensor 10 is discarded.

[0058] (f) As described in this embodiment, the number of metal components attached to the electrochemical sensor 10 is kept to a minimum, and in particular, the cover member 11, which has a large surface area, is free of metal components except for electrodes, etc., thereby reducing the cost of disposable parts and making it suitable for disposal as combustible waste.

[0059] (g) In this embodiment, the electrochemical sensor 10 is configured such that the detection surface of the sensor electrode 12b is exposed to the outer surface of the cylindrical cover member 11 through an opening 11c provided in the cover member 11. In other words, this very simple configuration of providing an opening 11c in the cylindrical cover member 11 makes it possible to attach the electrochemical sensor 10 to the stick-shaped tip 22 of the measuring instrument 20 and to bring the sensor electrode 12b into contact with the urine, which is the test fluid. Therefore, because of its very simple configuration, it is very suitable for disposable use, and the ease of insertion and removal of the stick-shaped tip 22 improves convenience for subjects using the electrochemical sensor 10, and can also contribute to reducing the cost of disposable parts.

[0060] (h) In this embodiment, the electrochemical sensor 10 is positioned such that the support substrate 12a closes the opening 11c of the cover member 11, and the positional relationship between the support substrate 12a and the cover member 11 is fixed by the fixing device 13. In other words, the positional relationship between the support substrate 12a and the cover member 11 is fixed using the simple configuration of the fixing device 13. Therefore, the configuration of the electrochemical sensor 10 is not complicated and is very simple, which in this respect is also very suitable for disposable use and can contribute to cost reduction of disposable parts.

[0061] (i) In particular, as described in this embodiment, if the fixing device 13 is adhesive tape, the positional relationship between the support substrate 12a and the cover member 11 can be fixed simply by applying the adhesive tape, and the planar shape of the fixing device 13 can be easily and flexibly adapted to various shapes. Therefore, in addition to being very useful in simplifying the configuration of the electrochemical sensor 10, it is also very useful from the viewpoint of the versatility of the electrochemical sensor 10, as it can easily and flexibly adapt to changes in the specifications of the sensor electrode 12b, for example.

[0062] (j) In this embodiment, the electrochemical sensor 10 is provided with a leaf spring structure 27 on at least one of the connecting electrode 12c and the terminal portion 26, and the connection between the connecting electrode 12c and the terminal portion 26 is established via the leaf spring structure 27. In this way, by utilizing the leaf spring structure 27, the connection (physical contact) between the connecting electrode 12c and the terminal portion 26 can be reliably established simply by inserting the stick-shaped tip portion 22 into the cylinder of the cover member 11. Moreover, even if there is some clearance inside the cylinder of the cover member 11 relative to the outer shape of the stick-shaped tip portion 22, the connection between the connecting electrode 12c and the terminal portion 26 can be established, and as a result, insertion and removal of the stick-shaped tip portion 22 into the cylinder of the cover member 11 can be made easier. Therefore, the electrochemical sensor 10 is extremely convenient for subjects using it.

[0063] (5) Variations etc. Although one embodiment of the present disclosure has been specifically described above, the present disclosure is not necessarily limited to the above-described content and can be modified in various ways without departing from its gist.

[0064] In the embodiments described above, an example was given in which the test fluid was urine, 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. Furthermore, the test fluid is not limited to human origin, but may be derived from animals such as dogs or cats.

[0065] In the embodiments described above, an example was given in which the specific substance contained in the test solution is uric acid, but this disclosure is not limited to such embodiments. For example, the specific substance contained in the test solution may be other than uric acid, such as urinary glucose, arginine, albumin, etc.

[0066] In the embodiments described above, an example was given in which the concentration of a specific component in a test solution is measured by a three-electrode method, but this disclosure is not limited to such embodiments. For example, the concentration of a specific substance in a test solution may be measured by 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).

[0067] In the above-described embodiment, the use of the electrochemical sensor 10 was explained using the example of pouring the urine, which is the test fluid, onto the outer surface of the cover member 11. However, this disclosure is not limited to this embodiment. For example, even if the electrochemical sensor 10 is immersed in the stored test fluid so that the detection surface of the sensor electrode 12b of the electrochemical sensor 10 comes into contact with the test fluid, it is possible to measure the concentration of a specific substance in the test fluid.

[0068] In the embodiments described above, the case in which the electrochemical sensor 10 has one printed circuit board 12 was used as an example, but this disclosure is not limited to such embodiments. For example, there may be multiple printed circuit boards 12. Furthermore, the position in which the printed circuit boards 12 are arranged is not particularly limited, and they may be arranged on the back side of the position shown in Figure 1. Specifically, as long as they are arranged to be exposed on the outer surface of the cylinder of the cover member 11, the printed circuit boards 12 may be arranged on both the front side and the back side as shown in Figure 1. Furthermore, the same applies to the sensor electrodes 12b and connecting electrodes 12c, etc., and their number is not particularly limited. For example, multiple sensor electrodes 12b may be arranged on the support substrate 12a of the printed circuit board 12.

[0069] In the embodiments described above, the case in which the sensor electrode 12b and the connecting electrode 12c are arranged on the support substrate 12a of the printed circuit board 12 was used as an example, but the present disclosure is not limited to this configuration. For example, the sensor electrode 12b and the connecting electrode 12c may be directly attached to the cover member 11, eliminating the need for the printed circuit board 12.

[0070] (6) Preferred aspects of the present disclosure The following are preferred embodiments of this disclosure.

[0071] (Note 1) According to one aspect of this disclosure, A cover member formed in a cylindrical shape with one end open and the other end sealed, A sensor electrode having a detection surface that comes into contact with the test liquid, and the detection surface is arranged so as to be exposed on the outer surface of the cylinder of the cover member, It comprises a connecting electrode that is electrically connected to the detection surface and is arranged to be exposed on the inner surface of the cylinder of the cover member, With the stick-shaped tip of the measuring instrument inserted into the cylindrical interior from the open end of the cover member, the terminal portion formed on the stick-shaped tip is configured to be electrically connected to the connecting electrode. An electrochemical sensor is provided.

[0072] (Note 2) Preferably, The device is configured to bring the liquid to be tested into contact with the outer surface of the cover member, thereby bringing the detection surface exposed to the outer surface of the cylinder into contact with the liquid to be tested, and to provide the reaction of the detection surface that occurs upon contact with the liquid to the measuring instrument. The electrochemical sensor described in Appendix 1 is provided.

[0073] (Note 3) Preferably, The sensor electrode comprises a diamond film that generates an oxidation-reduction reaction corresponding to the applied voltage when the test liquid is attached to it, and a support member that supports the diamond film. The detection surface is formed by the diamond film. An electrochemical sensor as described in Appendix 1 or 2 is provided.

[0074] (Note 4) Preferably, The cover member has drip-proof properties. An electrochemical sensor according to any one embodiment of Appendix 1 to 3 is provided.

[0075] (Note 5) Preferably, The cover member is formed of a flammable material. An electrochemical sensor according to any one embodiment of Appendix 1 to 4 is provided.

[0076] (Note 6) Preferably, Except for the sensor electrode and the connecting electrode, no metal members are attached to the cover member. An electrochemical sensor according to any one embodiment of Appendix 1 to 5 is provided.

[0077] (Note 7) Preferably, The cover member is provided with an opening that connects the outer surface of the cylinder and the inner surface of the cylinder. The sensor electrode is configured to have its detection surface exposed through the opening. An electrochemical sensor according to any one embodiment of Appendix 1 to 6 is provided.

[0078] (Note 8) Preferably, A support substrate that supports the sensor electrode and the connecting electrode, A fixing device for fixing the positional relationship between the support substrate and the cover member, An electrochemical sensor according to any one embodiment of appendices 1 to 7 is provided, comprising the features described above.

[0079] (Note 9) Preferably, The fastener is adhesive tape. The electrochemical sensor described in Appendix 8 is provided.

[0080] (Note 10) Preferably, At least one of the connecting electrode and the terminal portion is provided with a leaf spring structure to ensure connection between them. An electrochemical sensor according to any one embodiment of Appendix 1 to 9 is provided. [Explanation of Symbols]

[0081] 10 Electrochemical Sensors 11 Cover member 11a Open end 11b Sealed end 11c opening 12 Printed circuit boards 12a Support board 12b Sensor electrode 12b-1 Working electrode 12b-2 Counter electrode 12b-3 Reference electrode 12c connection electrode 12d Via section 13 Fixtures 13a,13b opening 20 Measuring instruments 21 Case section 22 Stick-shaped tip 24 Operation Buttons 25 LED lamps 26 Terminal section 27. Leaf spring structure

Claims

1. A cover member formed in a cylindrical shape with one end open and the other end sealed, A sensor electrode having a detection surface that comes into contact with the test liquid, and the detection surface is arranged so as to be exposed on the outer surface of the cylinder of the cover member, A connecting electrode is provided which is electrically connected to the detection surface and is exposed on the inner surface of the cylinder of the cover member, The system comprises a support substrate that supports the sensor electrode and the connecting electrode, The sensor electrode and the connecting electrode are arranged so as to be located on the front and back surfaces of the support substrate, and the detection surface of the sensor electrode and the connecting electrode are electrically connected via a via portion that penetrates the support substrate. With the stick-shaped tip of the measuring instrument inserted into the cylindrical interior from the open end of the cover member, the terminal portion formed on the stick-shaped tip is configured to be electrically connected to the connecting electrode. Electrochemical sensor.

2. The device is configured to bring the liquid to be tested into contact with the outer surface of the cover member, thereby bringing the detection surface exposed to the outer surface of the cylinder into contact with the liquid to be tested, and to provide the reaction of the detection surface that occurs upon contact with the liquid to the measuring instrument. The electrochemical sensor according to claim 1.

3. The sensor electrode comprises a diamond film that generates an oxidation-reduction reaction corresponding to the applied voltage when the test liquid is attached to it, and a support member that supports the diamond film. The detection surface is formed by the diamond film. The electrochemical sensor according to claim 1 or 2.

4. The cover member has drip-proof properties. The electrochemical sensor according to claim 1 or 2.

5. The cover member is formed of a flammable material. The electrochemical sensor according to claim 1 or 2.

6. Except for the sensor electrode and the connecting electrode, no metal members are attached to the cover member. The electrochemical sensor according to claim 1 or 2.

7. The cover member is provided with an opening that connects the outer surface of the cylinder and the inner surface of the cylinder. The sensor electrode is configured to have its detection surface exposed through the opening. The electrochemical sensor according to claim 1 or 2.

8. A fixing device for fixing the positional relationship between the support substrate and the cover member, The electrochemical sensor according to claim 1 or 2, comprising:

9. The fastener is adhesive tape. The electrochemical sensor according to claim 8.

10. At least one of the connecting electrode and the terminal portion is provided with a leaf spring structure to ensure connection between them. The electrochemical sensor according to claim 1 or 2.

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