JP7303353B1 - Electrochemical sensors and electrochemical sensor systems - Google Patents

Abstract

Kind Code: A1 It is possible to flexibly respond to switching of the functions of each electrode by devising the arrangement of triode electrodes that constitute an electrochemical sensor. An electrochemical sensor used for measuring the concentration of a specific component in a test liquid, comprising at least three electrodes (21, 22, 23) arranged on the same substrate (10), wherein the three electrodes (21, 22, 23) At least two electrodes 21, 22 among 21, 22, 23 are constituted by diamond electrodes having the same structure and the same shape, said two electrodes 21, 22 each functioning as either a working electrode or a counter electrode. At the same time, one electrode 23 other than the two electrodes 21 and 22 among the three electrodes 21, 22 and 23 functions as a reference electrode, and the two electrodes 21 and 22 are the one electrode 23. They are arranged at symmetrical positions with respect to a virtual line 27 passing through a predetermined electrode reference point 26 as an axis of symmetry. [Selection drawing] Fig. 3

Description

The present invention relates to electrochemical sensors and electrochemical sensor systems.

As an electrochemical sensor for measuring the ozone concentration of ozonized water, there is an electrochemical sensor in which a triode of a working electrode, a counter electrode, and a reference electrode is composed of a conductive diamond electrode (see, for example, Patent Document 1). Such an electrochemical sensor measures the ozone concentration by measuring the current value between the working electrode and the counter electrode while at least the working electrode and the counter electrode are in contact with ozone water. The working electrode and the counter electrode are arranged so that they are adjacent to each other (so that the distance between them is short) among the tripolar electrodes arranged in parallel (for example, "Fig. "reference).

WO2020/091033

An electrochemical sensor uses three electrodes (especially working electrode and counter electrode) to detect the transfer of electrons due to an electrochemical reaction (e.g. redox reaction) in a test solution (e.g. ozone water). , to measure the concentration of a specific component (for example, ozone) in the test liquid. Therefore, the result of concentration measurement by an electrochemical sensor can be affected by the state of each electrode (for example, the surface state). In that case, if the function of each electrode is fixed, there is a risk that the desired measurement accuracy cannot be obtained or the measurement sensitivity is lowered due to individual differences in each electrode, deterioration in condition due to use, and the like.

The present disclosure makes it possible to flexibly respond to the switching of the functions of each electrode by devising the arrangement of the triode electrodes that make up the electrochemical sensor, and to improve the measurement accuracy and suppress the decrease in measurement sensitivity. We provide technology to

One aspect of the present disclosure is
An electrochemical sensor used to measure the concentration of a specific component in a test solution,
comprising at least three electrodes disposed on the same substrate;
At least two of the three electrodes are diamond electrodes having the same structure and shape,
each of the two electrodes functions as either a working electrode or a counter electrode, and one of the three electrodes other than the two electrodes functions as a reference electrode;
The two electrodes are arranged at symmetrical positions with respect to an imaginary line passing through a predetermined electrode reference point of the one electrode as an axis of symmetry.

According to the technique of the present disclosure, it is possible to flexibly cope with at least the switching of the functions of the working electrode and the counter electrode, and it is possible to improve the measurement accuracy and suppress the deterioration of the measurement sensitivity.

1 is a perspective view showing a schematic configuration example of an electrochemical sensor according to a first embodiment of the present disclosure; FIG. FIG. 2 is a cross-sectional view of the electrochemical sensor shown in FIG. 1 taken along the line AA; FIG. 2 is an explanatory diagram schematically showing one specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure; FIG. 2 is an explanatory diagram (part 1) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure; FIG. 2 is an explanatory diagram (part 2) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure; FIG. 3 is an explanatory diagram (part 3) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure; FIG. 4 is an explanatory diagram (part 4) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure; 1 is a block diagram showing a functional configuration example of an electrochemical sensor system according to a first embodiment of the present disclosure; FIG. FIG. 4 is a time chart diagram showing one specific example of processing operations in the electrochemical sensor system according to the first embodiment of the present disclosure; FIG. 4 is a time chart diagram showing another specific example of processing operations in the electrochemical sensor system according to the first embodiment of the present disclosure; FIG. 5 is an explanatory diagram schematically showing one specific example of electrode arrangement in the electrochemical sensor according to the second embodiment of the present disclosure; FIG. 10 is an explanatory diagram (part 1) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the second embodiment of the present disclosure; FIG. 2 is an explanatory diagram (part 2) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the second embodiment of the present disclosure; FIG. 2 is an explanatory diagram (part 1) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure; FIG. 2 is an explanatory diagram (Part 2) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure; FIG. 3 is an explanatory diagram (part 3) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure, where (a) is a top view, (b) is a side view, and (c) is a bottom view. FIG. 4 is an explanatory diagram (part 4) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure; FIG. 5 is an explanatory diagram (No. 5) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure; FIG. 6 is an explanatory diagram (No. 6) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure; 1 is a perspective view showing a specific configuration example of an electrochemical sensor according to the present disclosure; FIG. FIG. 20 is a six-sided view of the electrochemical sensor of FIG. 20, (a) is a plan view, (b) is a front view, (c) is a bottom view, (d) is a rear view, (e) is a right side view, (f) is a left side view.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description is an example, and the present disclosure is not limited to the illustrated aspects.

<First Embodiment>
First, a first embodiment of the present disclosure will be described.

(1) Configuration of electrochemical sensor The electrochemical sensor described in this embodiment is used to measure the concentration of a specific component in a sample liquid. The test liquid is, for example, ozone water in which ozone (O ₃ ) is dissolved in water (such as tap water). The specific component is, for example, ozone dissolved in ozone water. Concentration measurements are performed using, for example, linear sweep voltammetry (LSV). That is, the electrochemical sensor in this embodiment measures the ozone concentration ( _O3 concentration) in ozone water using LSV.

(overall structure)
In order to measure the ozone concentration in the ozone water, the electrochemical sensor in this embodiment is constructed as described below.
FIG. 1 is a perspective view showing a schematic configuration example of an electrochemical sensor according to the first embodiment of the present disclosure. FIG. 2 is a cross-sectional view of the electrochemical sensor shown in FIG. 1 taken along the line AA.

As shown in FIGS. 1 and 2, the electrochemical sensor 1 comprises three electrodes 21, 22, 23 arranged on a support substrate 10 which is the same base material (that is, one base material). ing. Three wirings (electrical wirings) electrically connected to each of the electrodes 21, 22, and 23 are provided on the surface of the support substrate (hereinafter also simply referred to as “substrate”) 10 on which the electrodes 21, 22, and 23 are arranged. 31, 32, 33 are spaced apart from each other. The wirings 31, 32, 33 on the substrate 10 are insulated so that the liquid to be tested does not contact the wirings 31, 32, 33 when the electrodes 21, 22, 23 are brought into contact with the liquid to be tested. It is covered with a waterproof member 40 made of a non-toxic material or the like.

(Substrate configuration)
The substrate 10 supports the electrodes 21, 22, and 23, and is formed as a strip-shaped sheet-like (plate-like) member extending in the longitudinal direction. The substrate 10 can be made of an insulating material such as composite resin, ceramic, glass, or plastic having insulating properties. The substrate 10 is preferably made of, for example, glass epoxy resin or polyethylene terephthalate (PET). Further, the substrate 10 may be a semiconductor substrate or a metal substrate configured so that the surfaces on which the electrodes 21, 22, and 23 are arranged have insulating properties. The substrate 10 has predetermined physical strength and mechanical strength, for example, strength that prevents it from bending or breaking while measuring the O ₃ concentration in the sample liquid.

(Electrode configuration)
The electrodes 21 , 22 , 23 are arranged side by side along the width direction of the substrate 10 . Details of the planar arrangement of the electrodes 21, 22, and 23 will be described later.

Of the three electrodes 21, 22, 23 arranged on the substrate 10, the two electrodes 21, 22 positioned at both ends of the arrangement are adapted to function as either working electrodes or counter electrodes. In addition, one electrode 23 other than these two electrodes 21 and 22, that is, one electrode 23 positioned between the two electrodes 21 and 22 functions as a reference electrode.

At least three electrodes 21, 22, 23, including at least two electrodes 21, 22 functioning as either working or counter electrodes, and preferably also one electrode 23 functioning as a reference electrode, are each a boron-doped diamond electrode (hereinafter , also referred to as “BDD electrodes”). A BDD electrode is an electrochemical electrode obtained by doping a diamond film with boron at a high concentration to give it metallic properties, and here it is used as a chip. The BDD electrode used this time is a chip-like electrode (electrode chip) including an electrode film 24 made of a metal polycrystalline diamond film or the like and a conductive substrate (hereinafter also simply referred to as “substrate”) 25. . The BDD electrode is configured as a vertical electrode that conducts from the back surface of the substrate 25 (that is, the surface opposite to the surface on which the electrode film 24 is provided).

Also, at least two, preferably three, electrodes 21, 22, 23 each have the same structure and the same shape, in addition to each being a BDD electrode. The “same structure” here means that each has the same laminated structure, that is, each has a laminated structure including the electrode film 24 and the substrate 25 . The term "same shape" as used herein means that each of the chips has the same planar shape, that is, the detection surface that functions as an electrode has the same planar shape and area, and the figures drawn by each planar shape are congruent. means that

In this specification, one BDD electrode of the two electrodes 21 and 22 functioning as either a working electrode or a counter electrode is also referred to as a first diamond electrode (first BDD electrode) 21. The other BDD electrode of the electrodes 21 and 22 is also called a second diamond electrode (second BDD electrode) 22 . The BDD electrode, which is one electrode 23 functioning as a reference electrode, is also called a third diamond electrode (third BDD electrode) 23 . These first BDD electrode 21 , second BDD electrode 22 and third BDD electrode 23 may be collectively referred to as electrode group 20 .

Each of the first BDD electrode 21 to the third BDD electrode 23 includes the electrode film 24 and the conductive substrate 25 as described above.

The electrode film 24 is made of polycrystalline diamond. Specifically, the electrode film 24 is a polycrystalline film (polycrystalline diamond film) composed of diamond crystals containing boron (B) as a dopant, that is, diamond crystals having p-type conductivity. A diamond crystal is a crystal in which carbon (C) atoms are arranged in a pattern called a diamond crystal structure. Alternatively, the electrode film 24 may be a B-doped diamond-like carbon (DLC) film. The B concentration in the electrode film 24 can be measured by secondary ion mass spectrometry (SIMS), and can be, for example, 5×10 ¹⁹ cm ⁻³ or more and 5×10 ²¹ cm ⁻³ or less. SIMS is a technique for measuring the concentration of a given substance by detecting ions (secondary ions) generated when the surface of the electrode film 24 is irradiated with beam-like ions (primary ions) using a mass spectrometer. .

The electrode film 24 is provided on one of the two main surfaces of the substrate 25 . In this specification, the main surface of the substrate 25 on which the electrode film 24 is provided is also referred to as "the crystal growth surface of the substrate 25". The electrode film 24 is provided over the entire crystal growth surface of the substrate 25 . The electrode film 24 causes a predetermined electrochemical reaction (for example, oxidation-reduction reaction of ozone) on the surface (exposed surface).

The electrode film 24 can be grown (deposited, synthesized) by a chemical vapor deposition (CVD) method, a physical vapor deposition (PVD) method, or the like. Examples of the CVD method include hot filament CVD using a tungsten filament, plasma CVD, and the like, and examples of the PVD method include an ion beam method and an ionization vapor deposition method. The thickness of the electrode film 24 can be, for example, 0.5 μm or more and 10 μm or less, preferably 1 μm or more and 6 μm or less, more preferably 2 μm or more and 4 μm or less.

As the conductive substrate 25, a flat substrate made of a low resistance material is used. As the substrate 25, a substrate composed mainly of silicon (Si) and containing a p-type dopant such as boron (B) at a predetermined concentration, for example, a p-type single crystal Si substrate can be used. A p-type polycrystalline Si substrate can also be used as the substrate 25 . The B concentration in the substrate 25 is, for example, 5×10 ¹⁸ cm ⁻³ or more and 1.5×10 ²⁰ cm ⁻³ or less, preferably 5×10 ¹⁸ cm ⁻³ or more and 1.2×10 ²⁰ cm ^{−3 or} less. can be done. By keeping the B concentration in the substrate 25 within the above range, it is possible to reduce the specific resistance of the substrate 25 while avoiding a decrease in manufacturing yield and deterioration in performance of the substrate 25 .

The thickness of the substrate 25 can be, for example, 350 μm or more. As a result, a commercially available single-crystal Si substrate having a diameter of 6 inches or 8 inches can be used as the substrate 25 as it is without adjusting the thickness by back wrapping. As a result, it becomes possible to improve the productivity of the BDD electrode and reduce the manufacturing cost. Although the upper limit of the thickness of the substrate 25 is not particularly limited, the thickness of a Si substrate generally available on the market at present is a single crystal Si substrate having a diameter of 12 inches and having a thickness of about 775 μm. Therefore, the upper limit of the thickness of the substrate 25 in the current technology can be set to about 775 μm, for example.

As the substrate 25, a substrate other than a substrate composed of Si as a main element (Si substrate) can be used. For example, as the substrate 25, a substrate configured using a compound of Si such as a silicon carbide substrate (SiC substrate) can be used.

It is also conceivable to use a metal substrate composed mainly of niobium (Nb), molybdenum (Mo), titanium (Ti), or the like as the substrate 25 . However, it is preferable to use a Si substrate as the substrate 25 because leakage current is likely to occur when a metal substrate is used.

The first BDD electrode 21 to the third BDD electrode 23 configured as described above can be formed using a known film formation technique.

(wiring configuration)
Wirings 31 , 32 , and 33 are arranged on the support substrate 10 from one end toward the other end in the longitudinal direction of the substrate 10 . Materials for forming the wirings 31, 32, 33 include copper (Cu), gold (Au), platinum (Pt), silver (Ag), various noble metals such as palladium (Pd), aluminum (Al), and iron (Fe). , various metals such as nickel (Ni), chromium (Cr), and titanium (Ti), alloys containing these noble metals or metals as main components, oxides of the above noble metals, metals, or alloys, and carbon. The wirings 31, 32, and 33 may be formed using the same material, or may be formed using different materials. The wirings 31, 32, 33 can be formed by a subtractive method, a semi-additive method, or the like. The wirings 31, 32, 33 can also be formed by a printing method such as screen printing, gravure printing, offset printing, inkjet printing, or a vapor deposition method.

One end of the wiring 31 is electrically connected to the first BDD electrode 21 via a conductive bonding material 34 (see FIG. 2). One end of the wiring 32 is electrically connected to the second BDD electrode 22 via a conductive bonding material 34 . One end of the wiring 33 is electrically connected to the third BDD electrode 23 via a conductive bonding material 34 . As the bonding material 34, a conductive paste (conductive adhesive), a conductive tape, or the like can be used.

The substrate 25 side of each of the first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23 (the surface opposite to the side where the electrode film 24 is laminated) is desirably metallized. Metals used for metallization include Au, Ag, Pt, Cu, Al, magnesium (Mg), Ni, Ti, Mo, tungsten (W), laminates and alloys thereof, and the like, which are used to mount semiconductor chips. technology can be applied. By performing the metallizing process, the connection resistance between the conductive substrate 25 and the bonding material 34 can be lowered, and the bonding strength can be increased.

By connecting the substrate 25 side of the first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23 to the wirings 31, 32, and 33, and furthermore, by performing a metallizing process on the substrate 25 side of the bonding surface, It is possible to prevent the current distribution in each of the BDD electrodes 21, 22, and 23 from being biased when measuring the ozone concentration, and even if any of the electrodes 21, 22, and 23 is used as the working electrode, the current distribution will be uniform over the entire electrode surface. It becomes possible to cause an electrochemical reaction.

By connecting the substrate 25 side of the first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23 to the wirings 31, 32, and 33, electric wiring is provided on the surface side of each of the BDD electrodes 21, 22, and 23. It is not necessary to cover the BDD electrodes 21, 22, and 23 with an insulating resin, so that the surfaces of the BDD electrodes 21, 22, and 23 can be prevented from being contaminated, and the surfaces of the BDD electrodes 21, 22, and 23 can be kept flat without unevenness. As a result, even if any of the electrodes 21, 22, 23 is used as the working electrode, the diffusion path of ozone around each BDD electrode 21, 22, 23 can be made the same when measuring the ozone concentration, Any of the electrodes 21, 22, and 23 can be used as the working electrode to measure the ozone concentration with an equivalent circuit.

Around the junction between the first BDD electrode 21 and the wiring 31, around the junction between the second BDD electrode 22 and the wiring 32, and around the junction between the third BDD electrode 23 and the wiring 33, It is sealed with an insulating resin 35 (see FIG. 2). The insulating resin 35 can be composed of a thermosetting resin or an ultraviolet curable resin. As the thermosetting resin or ultraviolet curable resin, an epoxy-based insulating resin, a novolac-based insulating resin, or the like can be used. The insulating resin 35 is, for example, a liquid insulating resin before curing (hereinafter also referred to as “liquid resin”), which is applied around the bonding materials 34, the first BDD electrode 21, the second BDD electrode 22 and the third electrode. It can be provided by coating around and around each of the BDD electrodes 23 and curing the liquid resin by heating or ultraviolet irradiation. The liquid resin is applied and cured by electrically connecting the first BDD electrode 21 and the wiring 31, electrically connecting the second BDD electrode 22 and the wiring 32, and electrically connecting the third BDD electrode 23 and the wiring 33. and are electrically connected. For example, the liquid resin is applied so as to cover the bonding material 34, the side surface of the first BDD electrode 21, the side surface of the second BDD electrode 22, and the side surface of the third BDD electrode 23 without exposing them. Also, the liquid resin is applied to the surface of the first BDD electrode 21, the surface of the second BDD electrode 22, and the surface of the third BDD electrode 23 so as not to adhere. In addition, the “surface of the first BDD electrode 21,” the “surface of the second BDD electrode 22,” and the “surface of the third BDD electrode 23” respectively mean the surface of the electrode film 24 of each electrode, and specifically Specifically, of the two main surfaces of the electrode film 24 , it means the surface opposite to the surface in contact with the substrate 25 . The "surface of the first BDD electrode 21", the "surface of the second BDD electrode 22", and the "surface of the third BDD electrode 23" are surfaces (detection surfaces) that contribute to detection of ozone in the sample liquid. I can say.

In addition, in this embodiment, at least the two electrodes 21 and 22 functioning as either the working electrode or the counter electrode have the same structure and the same shape. 32, the bonding material 34 that electrically connects the electrodes 21, 22 and the wirings 31, 32, and the insulating resin 35 that seals the periphery of the bonding portion 34, have the same structure (material ), preferably having the same shape. This is because the first circuit 52 and the second circuit 53, which will be described later, can be equivalent.

(Electrode arrangement)
Next, specific examples will be given to explain how the electrodes 21, 22, and 23 are arranged on the support substrate 10 in the electrochemical sensor 1 having the configuration described above.

FIG. 3 is an explanatory diagram schematically showing one specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure.
As shown in FIG. 3, on the substrate 10, the first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23, which are the three electrodes 21, 22, and 23, are arranged along the lateral direction of the substrate 10. are arranged side by side. More specifically, the first BDD electrode 21 and the second BDD electrode 22 are arranged in parallel so that the third BDD electrode 23 is positioned between them.

The planar shape of each of the electrodes 21, 22, and 23 can be, for example, a rectangular shape having long sides arranged along the longitudinal direction of the substrate 10, but is not limited thereto, and is square or circular. Any shape is acceptable. However, at least the first BDD electrode 21 and the second BDD electrode 22, preferably all of the first BDD electrode 21 to the third BDD electrode 23, each have the same planar shape.

The plane area of each electrode 21, 22, 23 is not particularly limited, but is, for example, 1 mm ² or more, preferably 4 mm ² or more, more preferably 10 mm ^{2 or} more, still more preferably 20 mm ² or more, preferably It is 100 mm ² or less, more preferably 50 mm ² or less. The “planar area” referred to here is the area when each electrode 21, 22, 23 is viewed from above the main surface of the substrate 10 in the vertical direction, and is the surface that contributes to the detection of ozone in the test liquid. It corresponds to the area of (detection surface).
If the plane area of each of the electrodes 21, 22, and 23 is 1 mm ² or more, the electrodes 21, 22, and 23 can be stably and easily manufactured with high accuracy, and the reduction in handling and mounting stability can be prevented. can also be suppressed.
If the plane area of each of the electrodes 21, 22, 23 is 100 mm ² or less, the electrochemical sensor 1 can be prevented from becoming large, that is, the electrochemical sensor 1 can be easily obtained in a small size. Furthermore, by setting the plane area of each electrode 21, 22, 23 to 50 mm ² or less, it is possible to reliably avoid an increase in the size of the sensor 1 while obtaining a highly sensitive sensor 1 .

Among the electrodes 21, 22, and 23 arranged in parallel on the substrate 10, the first BDD electrode 21 and the second BDD electrode 22 are connected to a predetermined electrode reference point 26 on the third BDD electrode 23 positioned between them. are arranged at symmetrical positions with respect to an imaginary line 27 passing through the . Here, the “predetermined electrode reference point 26 on the third BDD electrode 23 ” is a positional reference point set in advance for the third BDD electrode 23 . Specifically, for example, the center of gravity or the central point of the planar shape of the third BDD electrode 23 can be exemplified as the electrode reference point 26 . Also, the “imaginary line 27 passing through the electrode reference point 26 ” is a line assumed to pass through the electrode reference point 26 . Specifically, a straight line passing through the electrode reference point 26 and extending along the longitudinal direction of the substrate 10 can be exemplified as a virtual line 27 passing through the electrode reference point 26 .

In this manner, on the substrate 10, the first BDD electrode 21 and the second BDD electrode 22 are arranged at line-symmetrical positions with the virtual line 27 passing through the electrode reference point 26 of the third BDD electrode 23 as the axis of symmetry. ing. Therefore, the first BDD electrode 21 and the second BDD electrode 22 have the same planar shape, and are positioned equidistant from the virtual line 27 passing through the electrode reference point 26 of the third BDD electrode 23. will be placed in

As with the first BDD electrode 21 and the second BDD electrode 22, the substrate 10 on which the electrodes 21, 22, and 23 are arranged is also preferably formed in a symmetrical planar shape. In other words, the substrate 10 preferably has symmetry in its planar shape with the virtual line 27 passing through the electrode reference point 26 of the third BDD electrode 23 as the axis of symmetry. In the case of symmetry, the virtual line 27 passing through the electrode reference point 26 of the third BDD electrode 23 on the substrate 10 passes through the center of the substrate 10 in the lateral direction. Further, when the corner of the substrate 10 is provided with the chamfered portion 11 that is subjected to R processing, chamfering, or the like, the chamfered portion 11 is formed by forming a virtual line 27 that passes through the electrode reference point 26 of the third BDD electrode 23. It will be located on each side of both sides.

In the specific example described above, the configuration in which the first BDD electrode 21 to the third BDD electrode 23 are arranged along the lateral direction of the substrate 10 has been described. The arrangement is not limited to this. That is, the electrodes 21, 22, and 23 may be arranged in other manners as long as the first BDD electrode 21 and the second BDD electrode 22 are line-symmetrical.

FIG. 4 is an explanatory diagram (Part 1) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure.
In the arrangement mode shown in FIG. 4, the first BDD electrode 21 to the third BDD electrode 23 are arranged on the substrate 10 along the longitudinal direction of the substrate 10 . Then, the first BDD electrode 21 and the second BDD electrode 22 are arranged with a virtual line 27 passing through the electrode reference point 26 of the third BDD electrode 23 located between the first BDD electrode 21 and the second BDD electrode 22 as an axis of symmetry. are arranged at symmetrical positions. That is, the imaginary line 27 serving as the axis of symmetry is arranged so as to extend along the lateral direction of the substrate 10 . In such an arrangement mode as well, the first BDD electrode 21 and the second BDD electrode 22 have the same planar shape, and each of them passes through the electrode reference point 26 of the third BDD electrode 23 . They are arranged at positions equidistant from the line 27 .

Further, in each of the above-described specific examples, the configuration in which the first BDD electrode 21 to the third BDD electrode 23 are arranged in a row on the substrate 10 has been described, but the arrangement of the electrodes 21, 22, and 23 is this. is not limited to
FIG. 5 is an explanatory diagram (Part 2) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure.
In the arrangement mode shown in FIG. 5, the first BDD electrode 21 and the second BDD electrode 22 are arranged along the width direction of the substrate 10 on the substrate 10, but the third BDD electrode 23 is separated from the row. The electrodes 21, 22, and 23 are arranged so that . Then, the first BDD electrode 21 and the second BDD electrode 22 are arranged in line-symmetrical positions with respect to a virtual line 27 passing through the electrode reference point 26 of the third BDD electrode 23 as an axis of symmetry. In such an arrangement mode as well, the first BDD electrode 21 and the second BDD electrode 22 have the same planar shape, and each of them passes through the electrode reference point 26 of the third BDD electrode 23 . They are arranged at positions equidistant from the line 27 .
With such an arrangement mode, the distance between the first BDD electrode 21 and the second BDD electrode 22 can be made closer than when the first BDD electrode 21 to the third BDD electrode 23 are arranged in a line. Therefore, the electrochemical sensor 1 can be easily made compact.

Further, in each of the above-described specific examples, the configuration in which the first BDD electrode 21 to the third BDD electrode 23 all have the same planar shape has been described, but the arrangement of the electrodes 21, 22, and 23 is limited to this. not a thing
FIG. 6 is an explanatory diagram (No. 3) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure. FIG. 7 is an explanatory diagram (No. 4) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the first embodiment of the present disclosure.
6 or 7, the third BDD electrode 23 functioning as a reference electrode is formed in a planar shape different from that of the first BDD electrode 21 and the second BDD electrode 22. In FIG. On the other hand, the first BDD electrode 21 and the second BDD electrode 22 are arranged at line-symmetrical positions with respect to an imaginary line 27 passing through the electrode reference point 26 of the third BDD electrode 23 as an axis of symmetry. In such an arrangement mode as well, the first BDD electrode 21 and the second BDD electrode 22 have the same planar shape, and each of them passes through the electrode reference point 26 of the third BDD electrode 23 . They are arranged at positions equidistant from the line 27 .

(2) System Configuration Next, an electrochemical sensor system including the electrochemical sensor 1 described above will be described.
FIG. 8 is a block diagram showing a functional configuration example of the electrochemical sensor system according to the first embodiment of the present disclosure.

As shown in FIG. 8, an electrochemical sensor system (hereinafter also simply referred to as “system”) is configured with an electrochemical measuring device 2 in addition to an electrochemical sensor 1 . A computer device 3 is connected to the electrochemical measurement device 2 . Note that the electrochemical measurement device 2 and the computer device 3 may be configured as an integrated device.

(Electrochemical sensor)
The electrochemical sensor 1 comprises a first BDD electrode 21, a second BDD electrode 22 and a third BDD electrode 23 as described above. The first BDD electrode 21 functions as either a working electrode or a counter electrode. Similarly, the second BDD electrode 22 also functions as either a working electrode or a counter electrode. However, the first BDD electrode 21 and the second BDD electrode 22 function as different electrodes. The third BDD electrode 23 functions as a reference electrode.

(Electrochemical measurement device)
An electrochemical measuring device (hereinafter also simply referred to as a “measuring device”) 2 functions as, for example, a potentiostat, and controls the electrochemical reactions at the electrodes 21, 22, and 23 in contact with the sample liquid. , is used to measure its potential and current.

The measuring device 2 in the present embodiment is configured with an electrochemical measuring circuit (hereinafter also simply referred to as "measurement circuit") 51, a first circuit 52, a second circuit 53, and a selection circuit 54. there is

The measurement circuit 51 applies a voltage between the working electrode and the counter electrode by controlling the voltage applied to each electrode 21, 22, 23, and allows the potential of the working electrode to be swept based on the potential of the reference electrode. is. Furthermore, the measuring circuit 51 measures the current value between the working electrode and the counter electrode according to the electrochemical reaction occurring at the working electrode. That is, the measurement circuit 51 performs electrochemical measurement by the three-electrode method using LSV. Details of the LSV can be obtained by using a known technique, and the explanation thereof is omitted here.

The first circuit 52 connects the wires 31, 32 in the electrochemical sensor 1 so that one of the two electrodes 21, 22, which functions as either a working electrode or a counter electrode, functions as a working electrode and the other as a counter electrode. and the measuring circuit 51 are electrically connected. Specifically, the first circuit 52 connects between the wirings 31 and 32 and the measurement circuit 51 so that the first BDD electrode 21 functions as a working electrode and the second BDD electrode 22 functions as a counter electrode. Consists of circuit patterns.

Contrary to the first circuit 52, the second circuit 53 connects the wires 31 and 32 in the electrochemical sensor 1 so that one of the two electrodes 21 and 22 functions as a counter electrode and the other functions as a working electrode. It electrically connects with the circuit 51 . Specifically, the second circuit 53 connects between the wirings 31 and 32 and the measurement circuit 51 so that the first BDD electrode 21 functions as a counter electrode and the second BDD electrode 22 functions as a working electrode. Consists of circuit patterns.

In both the first circuit 52 and the second circuit 53, wiring in the electrochemical sensor 1 is arranged so that the third BDD electrode 23, which is one electrode 23 other than the two electrodes 21 and 22, functions as a reference electrode. 33 and the measuring circuit 51 are connected.

Also, the first circuit 52 and the second circuit 53 are circuits equivalent to each other. An equivalent circuit means that the electric circuit is equivalent when electrochemical measurement is performed, and at the same time, the electrochemical reaction during measurement proceeds in an equivalent environment. In particular, in order for the electrochemical reaction to proceed in the same environment, the shape of each electrode connected to each circuit, the area of the electrode that contributes to the reaction, the arrangement of each electrode (equal or symmetrical arrangement), the spacing, etc. must be

The selection circuit 54 selects either the first circuit 52 or the second circuit 53 when applying voltage and measuring the current value by the measurement circuit 51, and selects each wiring 31, 32, 33 in the electrochemical sensor 1 and the measurement circuit. 51 to establish an electrical connection. That is, the selection circuit 54 switches between the first circuit 52 and the second circuit 53 to establish the electrical connection between the wirings 31 , 32 , 33 and the measurement circuit 51 . The selection circuit 54 can be configured using a known switch circuit. Selection switching by the selection circuit 54 may be based on an instruction from the outside (for example, the computer device 3) or may be based on the operation of the system user.

(computer device)
The computer device 3 is used by being connected to the measuring device 2, and is not limited to a stationary type represented by a personal computer device as long as it has an information processing function to execute a predetermined program. A representative portable information terminal device or the like may be used.

The computer device 3 is configured to function as a control section 60 that controls processing operations in the measuring device 2 by executing a predetermined program. The control performed by the control unit 60 includes control of the electrochemical measurement process, that is, control of the process of measuring the O ₃ concentration in the ozone water, which is the test liquid, based on the measurement result of the current value by the measuring device 2 .

The control unit 60 also functions as a selection control unit 61, a measured value management unit 62, and an energization control unit 63 by executing a predetermined program.

The selection control section 61 gives an instruction to switch the selection between the first circuit 52 and the second circuit 53 to the selection circuit 54 in the measuring device 2 . That is, the selection control section 61 switches between the first circuit 52 and the second circuit 53 by controlling the selection circuit 54 . Selection switching between the first circuit 52 and the second circuit 53 by the selection control unit 61 is performed at preset regular timings. A specific example of the regular timing will be described in detail later.

The measured value management unit 62 manages the current value measurement result (hereinafter also simply referred to as “measured value”) obtained through the measurement circuit 51 of the measuring device 2 . More specifically, the measured value management unit 62 acquires a plurality of measured values obtained when the connection is established by the first circuit 52 and when the connection is established by the second circuit 53, and based on these measured values Then, one measured value is derived, and the derived one measured value is used as the measured value for measuring the _O3 concentration in the ozone water, which is the test liquid. Specific examples of acquisition of multiple measured values and derivation of one measured value by the measured value management unit 62 will be described later in detail.

The energization control section 63 controls the state of energization of the electrodes 21 , 22 , 23 of the electrochemical sensor 1 by the measuring circuit 51 of the measuring device 2 . More specifically, the energization control unit 63 supplies the electrodes 21, 22, and 23 of the electrochemical sensor 1 with signals necessary for measuring the concentration of O ₃ in the ozone water, which is the sample liquid, from the measurement circuit 51 of the measurement device 2. Separately (that is, at a timing different from the energization), energization is performed in a manner different from that for measuring the O ₃ concentration, whereby each electrode 21, 22, 23 state recovery processing. Concrete examples of energization control by the energization control unit 63 and state recovery processing by this will be described later in detail.

(3) System Processing Operation Next, the processing operation of the above-described system will be described by exemplifying the case of measuring the O ₃ concentration in ozone water, which is a sample liquid.

(Concentration measurement processing)
When measuring the concentration of O ₃ in the ozonized water, which is the sample liquid, using the system described above, the electrodes 21, 22, 23 of the electrochemical sensor 1 are brought into contact with the ozonated water. At this time, it is desirable to secure a sufficient amount of ozone water, which is the test liquid, for the electrochemical sensor 1 . This is because if the amount of ozonized water is small, there is a possibility that accurate concentration measurement will not be possible due to the effect of consuming ozone during concentration measurement. Moreover, it is desirable that the ozone water with which the electrodes 21, 22, and 23 are brought into contact is kept in a stationary state without stirring, that is, in a state in which no liquid flow occurs. This is for the purpose of matching the respective measurement conditions when performing selection switching, which will be described later. Then, with the electrodes 21, 22, and 23 in contact with the ozone water, the measurement circuit 51 of the measurement device 2 controls the voltage applied to the electrodes 21, 22, and 23 to control the voltage between the working electrode and the counter electrode. is applied, the potential of the working electrode is swept relative to the potential of the reference electrode, and the value of the current flowing between the working electrode and the counter electrode is measured.

(selection switching)
At this time, the selection circuit 54 of the measuring device 2 selects either the first circuit 52 or the second circuit 53 while following an instruction from the selection control section 61 of the computer device 3 to select the electrodes 21, 22, 23 and the measuring circuit 51 are established. As a result, for example, when the first circuit 52 is selected, the _O3 concentration in the ozone water is measured while the first BDD electrode 21 functions as a working electrode and the second BDD electrode 22 functions as a counter electrode. Become. Further, for example, when the second circuit 53 is selected, the O ₃ concentration in the ozone water is measured while the first BDD electrode 21 functions as a counter electrode and the second BDD electrode 22 functions as a working electrode. . In other words, the presence of the first circuit 52, the second circuit 53 and the selection circuit 54 allows the selection of which of the first BDD electrode 21 and the second BDD electrode 22 functions as the working electrode or the counter electrode. It has become.

The first BDD electrode 21 and the second BDD electrode 22 corresponding to such selective switching each have the same laminated structure, each have a detection surface with the same planar shape and area, and further It is arranged at a line-symmetrical position with respect to a virtual line 27 passing through the electrode reference point 26 of the third BDD electrode 23 . That is, the first BDD electrode 21 and the second BDD electrode 22 have the same structure and the same shape, and are arranged at positions equidistant from the third BDD electrode 23 functioning as a reference electrode. The conditions are exactly the same, except that the arrangement of each configuration viewed from the BDD electrode 23 is left-right symmetrical.

Therefore, regardless of which of the first BDD electrode 21 and the second BDD electrode 22 is caused to function as the working electrode by selective switching, it is possible to suppress the occurrence of functional differences. Thus, the first BDD electrode 21 and the second BDD electrode 22 can both function as a working electrode or a counter electrode depending on their arrangement configuration, and selection of the function (if only fixed selection (including the switching of the selection).

Further, in the electrochemical sensor 1, if not only the first BDD electrode 21 and the second BDD electrode 22 but also the substrate 10 supporting them are formed in a symmetrical planar shape, a functional difference occurs. is more effective in suppressing When measuring the _O3 concentration in the ozonated water, which is the sample liquid, the _O3 in the ozonated water is consumed on the electrode surface of either the first BDD electrode 21 or the second BDD electrode 22 functioning as a working electrode. On the other hand, O ₃ diffuses from a position away from the working electrode and is supplied to the electrode surface. This is because no matter which one of the electrodes 22 and 22 is selected as the working electrode, no difference can be caused in the diffusion supply route of O ₃ to the electrode surface.

(switching timing)
The selection control unit 61 instructing the selection circuit 54 performs the selection switching as described above at preset regular timings. This enables the selection control unit 61 to automatically (forcibly) switch the selection between the first circuit 52 and the second circuit 53 . A specific example will be given below of the periodic timing of selection switching.

FIG. 9 is a time chart diagram showing one specific example of processing operations in the electrochemical sensor system according to the first embodiment of the present disclosure.
In the specific example shown in FIG. 9, when starting to measure the O ₃ concentration in the ozone water, the selection circuit 54 first selects the first circuit 52 to establish a physical connection (step 101, hereinafter step is abbreviated as "S"). Then, a state in which the first BDD electrode 21 functions as a working electrode and the second BDD electrode 22 functions as a counter electrode is detected by one circuit from the start of sweeping to the end of sweeping with respect to the potential of the working electrode potential with respect to the reference electrode. As a unit, continue until the detection execution unit ends.

After that, when the detection execution unit by the first circuit 52 ends, the selection circuit 54 switches the selection at that timing (S102). By this selection switching, the selection circuit 54 selects the second circuit 53 to establish electrical connection between the electrodes 21, 22, 23 and the measurement circuit 51 (S103). Then, the state in which the first BDD electrode 21 functions as a counter electrode and the second BDD electrode 22 functions as a working electrode is continued until the detection execution unit ends.

For all the circuits that can be selected by the selection circuit 54, that is, for each of the first circuit 52 and the second circuit 53, when the detection execution unit using these ends, the _O3 concentration in the ozone water is measured once. is assumed to have ended. In this manner, the selection circuit 54 selects the timing (that is, each detection execution timing) each time detection is performed by the first circuit 52 and the second circuit 53 from the start to the end of one concentration measurement. The selection switching between the first circuit 52 and the second circuit 53 is performed at the timing each time the unit ends.

That is, in the specific example shown in FIG. 9, selection switching between the first circuit 52 and the second circuit 53 is performed at preset periodic timing, and the timing is from the start to the end of one concentration measurement. The timing is set every time the detection by one circuit (the first circuit 52 or the second circuit 53) is executed in between. By performing selective switching at such timing, the measurement of the _O3 concentration in the ozone water under the same conditions is duplicated by the circuits 52 and 53 while selectively switching between the first circuit 52 and the second circuit 53. It is possible to do It should be noted that the timing described here may be the timing at which a predetermined interval period has been ensured from the end of the detection execution unit, in addition to the timing coincident with the end of the detection execution unit. The predetermined interval period is, for example, a period considered necessary for arranging the measurement environment for repeated measurements.

By performing selection switching at such timing, the following processing can be performed on current values (hereinafter also simply referred to as "measured values") which are measurement results obtained through the circuits 52 and 53. .

For example, the measured value management unit 62 of the computer device 3 acquires a plurality of measured values respectively obtained by the first circuit 52 and the second circuit 53 from the start to the end of one concentration measurement. Specifically, the measurement value management unit 62 acquires the measurement value obtained through the first circuit 52 at the end of the detection execution unit (S101) by the first circuit 52 (S104). Also, the measured value management unit 62 acquires the measured value obtained through the second circuit 53 at the end of the detection execution unit (S103) by the second circuit 53 (S105).

After acquiring these multiple measured values, the measured value management unit 62 derives one measured value based on the acquired multiple measured values (S106). As one measured value, for example, the maximum value corresponding to the best measurement result among a plurality of measured values, the average value obtained by removing noise components included in the plurality of measured values, a predetermined calculated value based on these, etc. can be used. When deriving one measurement value, for example, one measurement value may be derived using a plurality of measurement values after the second measurement, excluding the first measurement. This is because there is concern that the first measurement is likely to be affected by measurement errors.

Then, when the measured value management unit 62 derives one measured value, the control unit 60 of the computer device 3 performs processing necessary to specify the O ₃ concentration in the ozone water based on the one measured value. I do. Therefore, by deriving one measured value from a plurality of measured values obtained by overlapping concentration measurements performed by the circuits 52 and 53, for example, individual differences between the first BDD electrode 21 and the second BDD electrode 22, Even if one of the electrodes 21 and 22 is unable to obtain the desired measurement accuracy due to deterioration in the state of the electrodes 21 and 22 due to the use of the electrodes 21 and 22, its influence on the measured value as the concentration measurement result. It becomes possible to suppress the spread. In other words, it is possible to minimize the influence of the state (for example, surface state) of the electrodes 21 and 22 on the measured value of O ₃ concentration, and as a result, it is possible to improve the measurement accuracy. becomes.

In addition, when a plurality of measured values are obtained through each of the circuits 52 and 53, in addition to deriving one measured value from these, or without deriving one measured value, the obtained plurality of measured values are It is also possible to compare them with each other and detect the state (for example, the surface state) of each of the electrodes 21 and 22 from the comparison result. Specifically, by comparing the measured value obtained by the first circuit 52 and the measured value obtained by the second circuit 53, for example, when a difference greater than normal measurement variation occurs between them In addition, it is possible to detect the states of the electrodes 21 and 22, such as determining that either the first BDD electrode 21 or the second BDD electrode 22 has deteriorated due to surface contamination or the like. Therefore, by comparing a plurality of measured values obtained by overlapping concentration measurements performed by the respective circuits 52 and 53, when deterioration of the state of the electrodes 21 and 22 is detected, for example, an error message can be displayed. , it becomes possible to output information about the necessity of state recovery processing, the necessity of sensor replacement, etc., which will be described later, and as a result, it is possible to always maintain the optimum state of the system.

A specific example of the periodic timing for switching the selection of the circuits 52 and 53 has been described above, but the periodic timing for switching the selection is not limited to the above specific example.

FIG. 10 is a time chart diagram showing another specific example of processing operations in the electrochemical sensor system according to the first embodiment of the present disclosure.
In the specific example shown in FIG. 10 , when starting to measure the O ₃ concentration in the ozone water, the selection circuit 54 first selects the first circuit 52 to A physical connection is established (S201). Then, the state in which the first BDD electrode 21 functions as a working electrode and the second BDD electrode 22 functions as a counter electrode is continued from the start of the sweep of the potentials of the working electrode and the counter electrode to the end of the sweep. It is assumed that one concentration measurement has been completed for the O ₃ concentration. In other words, in one concentration measurement, duplicate detection is not performed by each circuit, which is different from the specific example described above (see FIG. 9).

After that, the O ₃ concentration of ozone water, which is a new sample liquid, is measured. The state in which the BDD electrode 21 functions as a working electrode and the second BDD electrode 22 functions as a counter electrode is continued. Although the figure shows a case where the density measurement is repeated three times, the number of times the density measurement is performed under the same conditions is not limited to this. may be repeated, or multiple times.

When the density measurement is completed n times, the selection circuit 54 switches the selection at that timing (S202). By this selection switching, the selection circuit 54 selects the second circuit 53 to establish electrical connection between the electrodes 21, 22, 23 and the measurement circuit 51 (S204). Then, the state in which the first BDD electrode 21 functions as a counter electrode and the second BDD electrode 22 functions as a working electrode is continued until n times of concentration measurements are finished.

In this manner, the selection circuit 54 switches between the first circuit 52 and the second circuit 53 each time the density measurement is performed once or multiple times. By performing selective switching at such timing, concentration measurement in an electrode configuration in which the same electrode serves as the working electrode is not repeated more than necessary. Therefore, it is possible to suppress deterioration of the electrode state (for example, the surface state) over time due to repeated concentration measurements.

In conjunction with this selection switching timing, the energization control unit 63 controls the state of energization to each of the electrodes 21, 22, and 23 so that each electrode 21, 22, and 23 is measured for the O ₃ concentration. The energization may be performed in a different mode (S203). As a result, the energization control unit 63 performs state recovery processing for the electrodes 21, 22, and 23 whose energization state is controlled.

Here, "energization in a manner different from the measurement of the _O3 concentration" means timing different from the measurement of the _O3 concentration in the ozone water that is the test liquid (for example, before or after the concentration measurement). This means, for example, performing an energization process with a current density higher than that in the concentration measurement, or performing an energization process with a current flowing in the opposite direction to that in the concentration measurement. If the energization treatment is performed in such a manner, the energization can oxidize the surface of the working electrode or generate bubbles on the surface of the working electrode. It is possible to restore contamination, deterioration, and the like. In other words, it is possible to perform a process of recovering contamination, deterioration, etc. of the surface of the working electrode over time through oxidation of the electrode surface, etc., as a "state recovery process" of the working electrode.

When performing the energization control for such state recovery processing, the energization control unit 63 performs the energization control in accordance with the timing of selection switching between the first circuit 52 and the second circuit 53. Either the first BDD electrode 21 functioning as a working electrode through the second circuit 53 or the second BDD electrode 22 functioning as a working electrode through the second circuit 53, or both.

For example, in the case of the first BDD electrode 21, the energization control unit 63 causes the first BDD electrode 21 to function as a working electrode and performs concentration measurement n times (that is, after the concentration measurement is completed). Then, the first BDD electrode 21 is energized for the state recovery process. That is, after n times of concentration measurement by the first BDD electrode 21 are completed, the state recovery processing of the first BDD electrode 21 is performed.

Further, for example, when performing the second BDD electrode 22, the energization control unit 63 causes the second BDD electrode 22 to function as a working electrode to perform n concentration measurements (i.e., prior to the concentration measurement ), the second BDD electrode 22 is energized for the state recovery process. That is, prior to the start of concentration measurement by the second BDD electrode 22, the state recovery processing of the second BDD electrode 22 is performed.

In the specific example shown in FIG. 10, the state recovery process is performed at the timing of switching from the first circuit 52 to the second circuit 53. Conversely, the second circuit 53 At the timing of switching to the first circuit 52 as well, the same state recovery processing may be performed. However, the timing of performing the state recovery process does not have to be every time the selection and switching between the first circuit 52 and the second circuit 53 are performed. The degree of deterioration may be detected, and the detection may be performed according to the detection result (that is, at the timing after electrode deterioration is detected).

If the first BDD electrode 21 or the second BDD electrode 22 is subjected to state recovery processing by the above-described energization control, for example, repeated measurements of the O ₃ concentration in the ozone water will prevent contamination and alteration of the electrode surface over time. Even if it occurs, it is possible to remove the contamination, deterioration, etc., and recover the state of the electrode surface. Therefore, by subjecting the first BDD electrode 21 or the second BDD electrode 22, which functions as a working electrode, to recovery treatment, it is possible to suppress a decrease in detection sensitivity induced by contamination or alteration of the electrode surface.

(4) Effect of this embodiment According to this embodiment, one or more of the following effects can be obtained.

(a) In the electrochemical sensor 1, the first BDD electrode 21 and the second BDD electrode 22 have the same structure and the same shape, and the first BDD electrode 21 and the second BDD electrode 22 are They are arranged symmetrically with respect to the third BDD electrode 23 . Therefore, the configuration conditions of the first BDD electrode 21 and the second BDD electrode 22 as viewed from the third BDD electrode 23 are exactly the same except for the symmetrical arrangement. Either can function as a working or counter electrode. Furthermore, it becomes possible to switch the function as a working electrode or a counter electrode.
Therefore, according to the electrode arrangement in the electrochemical sensor 1 of this embodiment, it is possible to select the electrode function according to the states of the first BDD electrode 21 and the second BDD electrode 22 . By selecting the electrode functions in this way, it is possible to improve the measurement accuracy of the concentration measurement results by selecting the electrodes, and to suppress the deterioration of the measurement sensitivity by switching the selection.
In other words, according to the electrochemical sensor 1 of the present embodiment, by devising the arrangement of the triode electrodes, it is possible to measure the _O3 concentration in the ozone water while selectively switching the electrode functions. It becomes possible to realize a sensor configuration that can ensure flexibility (versatility), and as a result, it becomes possible to improve measurement accuracy and suppress deterioration in measurement sensitivity.

(b) In the present embodiment, in the electrochemical sensor 1, in addition to the electrode arrangement, the substrate 10 supporting the electrodes 21, 22, and 23 is also formed in a symmetrical planar shape. If the substrate 10 has a symmetrical planar shape, regardless of which of the first BDD electrode 21 and the second BDD electrode 22 is selected as the working electrode, a difference occurs in the diffusion supply route of O ₃ to the electrode surface. can be avoided. Therefore, it is more effective in suppressing the occurrence of functional differences between the first BDD electrode 21 and the second BDD electrode 22, and the improvement of the measurement accuracy of the electrochemical sensor 1, suppression of deterioration in measurement sensitivity, etc. is very suitable for the realization of

(c) In the present embodiment, the specific component whose concentration is to be measured by the electrochemical sensor 1 is dissolved ozone in ozone water, which is the sample liquid. Therefore, the electrochemical sensor 1 of the present embodiment is suitable for use in measuring the _O3 concentration in ozone water, and it is possible to improve the measurement accuracy and suppress the decrease in measurement sensitivity for the _O3 concentration measurement.

(d) In the present embodiment, the electrochemical sensor system including the electrochemical sensor 1 includes a first circuit 52 and a second circuit 53 in addition to the electrochemical sensor 1, so that the electrochemical sensor 1 , which corresponds to selection switching of which of the first BDD electrode 21 and the second BDD electrode 22 is to function as the working electrode or the counter electrode.
Therefore, through such selection switching, in the electrochemical sensor system of the present embodiment, for example, the concentration measurement by the first circuit 52 and the concentration measurement by the second circuit 53 are respectively performed, and based on the measurement results of each This makes it possible to extract the final measurement results (select the better measurement results, average the measurement results to remove noise components, etc.), and as a result, improve the measurement accuracy of the concentration measurement results. become. Further, for example, by appropriately switching the concentration measurement by the first circuit 52 and the concentration measurement by the second circuit 53 as necessary, the concentration measurement of the electrode configuration in which the same electrode is the working electrode can be continuously repeated. As a result, deterioration of the measurement sensitivity due to deterioration of the surface condition (accumulation of dirt etc.) of the electrodes 21 and 22 can be suppressed.
That is, according to the electrochemical sensor system of the present embodiment, concentration measurement by the first circuit 52 and concentration measurement by the second circuit 53 are performed according to the respective states of the first BDD electrode 21 and the second BDD electrode 22. By appropriately switching the selection of , it is possible to improve the measurement accuracy of the electrochemical sensor 1 and suppress the decrease in measurement sensitivity.

(e) As described in the present embodiment, if selection switching between the first circuit 52 and the second circuit 53 is performed at preset regular timing, the selection switching is automatically (forcedly) performed. This is very effective in improving the measurement accuracy of the electrochemical sensor 1 and suppressing a decrease in measurement sensitivity.

(f) As described in the present embodiment, regarding the timing of selection switching between the first circuit 52 and the second circuit 53, every time detection by one circuit is executed from the start to the end of one concentration measurement. If the timing is set to , the O ₃ concentration measurement for ozone water under the same conditions can be performed redundantly while selectively switching between the first circuit 52 and the second circuit 53 . Therefore, it becomes possible to derive one measurement result from overlapping measurement results, which is very effective in improving the measurement accuracy of O ₃ concentration measurement.

(g) As described in the present embodiment, when measuring _O3 concentration in ozone water, one measurement result is derived from overlapping measurement results, and one derived measurement value is used as the measurement value for _O3 concentration measurement. Then, for example, due to individual differences between the first BDD electrode 21 and the second BDD electrode 22, state deterioration due to use, etc., there may be one in which the desired measurement accuracy cannot be obtained in either of the electrodes 21 and 22. Even if it is, it can be suppressed that its influence reaches the result of the concentration measurement. In other words, it is possible to eliminate the influence of the state (for example, surface state) of the electrodes 21 and 22 as much as possible, thereby improving the measurement accuracy of the O ₃ concentration measurement in the ozone water, which is the sample liquid. .

(h) As described in the present embodiment, regarding the timing of selection switching between the first circuit 52 and the second circuit 53, every time the O ₃ concentration measurement is performed n times (one or more times) If set, the O ₃ concentration measurement in the electrode configuration in which the same electrode serves as the working electrode will not be repeated more than necessary. Therefore, it becomes possible to suppress the deterioration of the electrode state (for example, the surface state) over time due to repeated O ₃ concentration measurement, and it is very effective in suppressing the deterioration of the measurement sensitivity of O ₃ concentration measurement. become something.

(i) As described in the present embodiment, the first BDD electrode 21 or the second BDD electrode 22 at a timing different from the measurement of the _O3 concentration in the ozone water (for example, before or after performing the _O3 concentration measurement) , is energized in a manner different from that for O ₃ concentration measurement, thereby performing state recovery processing of the first BDD electrode 21 or the second BDD electrode 22, for example, O ₃ concentration measurement Even if the electrode surface is contaminated or degraded over time due to the repetition of the above steps, the contamination or degradation can be removed and the state of the electrode surface can be recovered. Therefore, by performing a state recovery process on the first BDD electrode 21 or the second BDD electrode 22 that functions as a working electrode, it is possible to suppress the decrease in detection sensitivity induced by contamination or deterioration of the electrode surface, and as a result As a result, it is very effective in suppressing a decrease in the measurement sensitivity of O ₃ concentration measurement.

(j) As described in the present embodiment, by selectively switching between the first circuit 52 and the second circuit 53, _O3 concentration measurement for ozone water under the same conditions can be performed by the first circuit 52 and the second circuit. 53 can be performed redundantly while switching the selection for each. Thereby, it becomes possible to compare the measured value obtained by the first circuit 52 and the measured value obtained by the second circuit 53, and the surface contamination of either the first BDD electrode 21 or the second BDD electrode 22 is possible. , etc., it can be detected. Therefore, when the state deterioration of the electrodes 21 and 22 is detected, for example, an error message can be displayed, or information can be output about the necessity of state recovery processing, the necessity of sensor replacement, and the like. , and as a result, it becomes possible to always keep the system state optimal.

<Second embodiment>
Next, a second embodiment of the present disclosure will be described. Note that differences from the case of the first embodiment will be mainly described here.

(5) Configuration of electrochemical sensor In the electrochemical sensor 1 described in this embodiment, the arrangement of the electrodes 21, 22, and 23 on the support substrate 10 is different from that in the first embodiment described above. .

(Electrode arrangement)
FIG. 11 is an explanatory diagram schematically showing one specific example of electrode arrangement in the electrochemical sensor according to the second embodiment of the present disclosure. In addition, in the figure, the same reference numerals are given to the same components as in the case of the first embodiment.

In this embodiment, the three electrodes 21, 22, 23, the first BDD electrode 21, the second BDD electrode 22 and the third BDD electrode 23, each have the same structure and shape. The terms "same structure" and "same shape" used here have the same meanings as in the first embodiment. In addition, in this embodiment, the three electrodes 21, 22, 23 have the same structure and the same shape. 21, 22, 23 and the wirings 31, 32, 33, and the insulating resin 35, which seals the surroundings of the joints 34, have the same structure (material), It is desirable to have the same shape. This is because each of the first to sixth circuits, which will be described later, can be equivalent.

Since each of the three electrodes 21, 22, and 23 has the same structure and the same shape, in the present embodiment, in addition to the first BDD electrode 21 and the second BDD electrode 22, the third BDD electrode 23 also includes the function can correspond to the selection switching of That is, in this embodiment, the first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23 function as either a working electrode, a counter electrode, or a reference electrode, respectively.

In order to correspond to such selection switching, in the present embodiment, the first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23 are arranged around a predetermined base material reference point 28 on the substrate 10. They are arranged in positions of three-fold symmetry. Here, the “predetermined base material reference point 28 on the substrate 10 ” is a point on the substrate 10 that serves as a preset positional reference. Specifically, for example, when imaginary lines 27a, 27b, and 27c passing through the electrode reference points 26a, 26b, and 26c described in the first embodiment are assumed for each of the electrodes 21, 22, and 23, the substrate reference A point 28 is located at the intersection of the virtual lines 27a, 27b, 27c. In addition, "three-fold symmetry" means that at least a reference point (for example, each electrode It is the symmetry in which the electrode reference points 26a, 26b, 26c) of 21, 22, 23 overlap. With three-fold symmetry, lines connecting the electrode reference points 26a, 26b, 26c of the electrodes 21, 22, 23 form an equilateral triangle.

Thus, on the substrate 10 , the first BDD electrode 21 , the second BDD electrode 22 , and the third BDD electrode 23 are arranged at three-fold symmetrical positions with respect to the substrate reference point 28 . Therefore, for example, considering the first BDD electrode 21 as a reference, the second BDD electrode 22 and the third BDD electrode 23 have the same planar shape, and the electrode reference point of the first BDD electrode 21 They are in a symmetrical relationship with an imaginary line 27a passing through 26a as an axis of symmetry, and are arranged at positions equidistant from the imaginary line 27a. Further, for example, considering the second BDD electrode 22 as a reference, the first BDD electrode 21 and the third BDD electrode 23 have the same planar shape, and in addition, the electrode reference point of the second BDD electrode 22 They are in a symmetrical relationship with an imaginary line 27b passing through 26b as an axis of symmetry, and are arranged at positions equidistant from the imaginary line 27b. Further, for example, considering the third BDD electrode 23 as a reference, the first BDD electrode 21 and the second BDD electrode 22 have the same planar shape, and the electrode reference point of the third BDD electrode 23 They are in a symmetrical relationship with an imaginary line 27c passing through 26c as an axis of symmetry, and are arranged at positions equidistant from the imaginary line 27c.

In the specific example described above, the planar shape of the first BDD electrode 21 to the third BDD electrode 23 is a rectangular shape, and the long side directions thereof are arranged radially around the substrate reference point 28. However, the arrangement of the electrodes 21, 22, 23 is not limited to this. In other words, the electrodes 21, 22, and 23 may be arranged in other manners as long as they are arranged at three-fold symmetrical positions with respect to the substrate reference point .

FIG. 12 is an explanatory diagram (part 1) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the second embodiment of the present disclosure.
In the arrangement mode shown in FIG. 12, the plane shape of the first BDD electrode 21 to the third BDD electrode 23 is square. Each of the first BDD electrode 21 to the third BDD electrode 23 is arranged so that the constituent sides of the planar shape are aligned in the same direction. However, the electrode reference points 26a, 26b, and 26c of the electrodes 21, 22, and 23 are arranged at three-fold symmetrical positions with the substrate reference point 28 on the substrate 10 as the center. That is, the first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23, if at least the electrode reference points 26a, 26b, and 26c correspond to the three-fold symmetric arrangement, the electrode reference points 26a , 26b, and 26c.

Even in such an arrangement mode, the first BDD electrode 21 and the second BDD electrode 22 can be considered to be arranged symmetrically when viewed from the third BDD electrode 23 . Also, it can be assumed that the first BDD electrode 21 and the third BDD electrode 23 are arranged symmetrically when viewed from the second BDD electrode 22 . Further, it can be assumed that the second BDD electrode 22 and the third BDD electrode 23 are arranged symmetrically when viewed from the first BDD electrode 21 . In other words, the arrangement mode shown in FIG. 12 can be handled in the same way as the arrangement mode shown in FIG.

Further, in each of the above-described specific examples, the configuration in which the third BDD electrode 23 among the electrodes 21, 22, and 23 is positioned closest to the tip side of the substrate 10 has been described. , 23 is not limited to this.
FIG. 13 is an explanatory diagram (Part 2) schematically showing another specific example of electrode arrangement in the electrochemical sensor according to the second embodiment of the present disclosure.
In the arrangement shown in FIG. 13, the third BDD electrode 23 is positioned farthest from the tip of the substrate 10, contrary to the arrangement shown in FIG. 11 or FIG. In such an arrangement mode as well, the electrodes 21, 22, and 23 are arranged at three-fold symmetrical positions with the substrate reference point 28 on the substrate 10 as the center.
That is, in the second embodiment of the present disclosure, the relative positional relationship between each of the electrodes 21, 22, and 23 is set to have three-fold symmetry about the substrate reference point 28. For example, the relative positional relationship between the electrodes 21, 22, 23 and the substrate 10 is not particularly limited.

(6) System Configuration Next, a functional configuration example of the electrochemical sensor system according to the second embodiment of the present disclosure will be described. Although illustration of the system configuration is omitted here, the same components as in the case of the first embodiment are described using the same reference numerals.

The system exemplified in the second embodiment comprises the electrochemical sensor 1 in which the electrodes 21, 22, 23 are arranged with three-fold symmetry as described above. And the measuring device 2 is configured as follows so as to correspond to the electrochemical sensor 1 .

The measuring device 2 includes first to sixth circuits in addition to the measuring circuit 51 and the selecting circuit 54 .
In the first circuit, each wiring 31, 32, 33 and a measurement circuit 51 are arranged so that the first BDD electrode 21 functions as a working electrode, the second BDD electrode 22 functions as a counter electrode, and the third BDD electrode 23 functions as a reference electrode. It consists of a circuit pattern that electrically connects between
In the second circuit, each wiring 31, 32, 33 and the measurement circuit 51 are arranged so that the first BDD electrode 21 functions as a counter electrode, the second BDD electrode 22 functions as a working electrode, and the third BDD electrode 23 functions as a reference electrode. It consists of a circuit pattern that electrically connects between
In the third circuit, each wiring 31, 32, 33 and the measurement circuit 51 are arranged so that the first BDD electrode 21 functions as a working electrode, the second BDD electrode 22 functions as a reference electrode, and the third BDD electrode 23 functions as a counter electrode. It consists of a circuit pattern that electrically connects between
In the fourth circuit, each wiring 31, 32, 33 and the measurement circuit 51 are arranged so that the first BDD electrode 21 functions as a counter electrode, the second BDD electrode 22 functions as a reference electrode, and the third BDD electrode 23 functions as a working electrode. It consists of a circuit pattern that electrically connects between
The fifth circuit uses the first BDD electrode 21 as a reference electrode, the second BDD electrode 22 as a working electrode, and the third BDD electrode 23 as a counter electrode. It consists of a circuit pattern that electrically connects between
The sixth circuit uses the first BDD electrode 21 as a reference electrode, the second BDD electrode 22 as a counter electrode, and the third BDD electrode 23 as a working electrode. It consists of a circuit pattern that electrically connects between

Corresponding to these first to sixth circuits, the selection circuit 54 selects any one of the first to sixth circuits for voltage application and current value measurement by the measurement circuit 51, and selects one of the electrochemical sensors. 1 and the measuring circuit 51 to establish an electrical connection.

(7) System Processing Operation Next, the processing operation in the system described above will be described.

Also in the system of this embodiment, as in the case of the first embodiment, when measuring the _O3 concentration in the ozone water that is the sample liquid, the electrodes 21, 22, and 23 of the electrochemical sensor 1 are connected to ozone By controlling the voltage applied to each electrode 21, 22, 23 in contact with water, a voltage is applied between the working electrode and the counter electrode, and the potential of the working electrode is swept based on the potential of the reference electrode. , the value of the current flowing between the working electrode and the counter electrode at that time is measured.

At this time, the selection circuit 54 of the measuring device 2 selects any one of the first circuit to the sixth circuit while following the instruction from the selection control unit 61 of the computer device 3, and selects each electrode 21, 22, 23 and the measurement circuit 51 . In other words, it is adapted to select and switch whether each of the three electrodes 21, 22, and 23 functions as a working electrode, a counter electrode, or a reference electrode.

The first BDD electrode 21, the second BDD electrode 22, and the third BDD electrode 23 corresponding to such selective switching are arranged at three-fold symmetrical positions with the substrate reference point 28 as the center. Therefore, regardless of which of the first to sixth circuits is selected, the configuration of the working electrode and the counter electrode with respect to the reference electrode will be the same, and there will be no functional difference between the working electrode and the counter electrode. can be suppressed.

That is, in the present embodiment, not only the working electrode and the counter electrode but also the reference electrode can be used to select and switch these functions. As a result, it becomes possible to secure a greater degree of flexibility (versatility) in concentration measurement, and as a result, it becomes possible to further improve the measurement accuracy and suppress the decrease in measurement sensitivity. That is, in the above-described first embodiment, one measurement value is derived from two types of measurement results, but in this embodiment, one measurement value can be derived from three types of measurement results, so the measurement accuracy is higher. can be increased. In addition, it becomes easier to manage variations in the measurement results, and it is possible to increase the detection sensitivity of electrode deterioration and the like.

Also in this embodiment, selection switching of the functions of the electrodes 21, 22, and 23 is automatically (forcedly) performed at preset periodic timings.

For example, as an example of periodic timing, selection switching is performed for each circuit each time detection is performed by one circuit (one of the first to sixth circuits). Then, while the _O3 concentration in the ozonated water is measured under the same conditions in duplicate by each circuit, when all the detection execution units by each circuit are completed, one concentration measurement of the _O3 concentration in the ozonated water is completed. shall be
By switching the selection at such timing, it becomes possible to derive a single measured value from multiple measured values obtained by overlapping concentration measurements, and as a result, it is possible to improve the measurement accuracy. It becomes possible. Moreover, in this case, by supporting selection and switching of functions including not only the working electrode and the counter electrode but also the reference electrode, the number of base measurement values increases, contributing to further improvement in measurement accuracy. You will get

Further, for example, as another example of periodic timing, selection switching is performed for each circuit at timing each time concentration measurement is performed once or multiple times.
By performing selective switching at such timing, deterioration of the electrode state over time due to repeated concentration measurements can be suppressed. , it becomes possible to further suppress the degree of deterioration of the electrode state.

(8) Effects of this embodiment According to this embodiment, in addition to the effects described in the first embodiment, one or more of the following effects can be obtained.

(k) In the electrochemical sensor 1 of the present embodiment, the first BDD electrode 21, the second BDD electrode 22 and the third BDD electrode 23 have the same structure and shape, and each of the electrodes 21, 22, 23 are arranged at three-fold symmetrical positions with respect to the substrate reference point 28 . Therefore, each of these three electrodes 21, 22, 23 can function as a working electrode, a counter electrode or a reference electrode. Furthermore, it becomes possible to respond to switching of the function as a working electrode, a counter electrode, or a reference electrode.
Therefore, according to the electrode arrangement in the electrochemical sensor 1 of the present embodiment, by devising the arrangement of the triode electrodes, it is possible to measure the _O3 concentration in the ozone water while selectively switching the electrode functions, for example. It becomes possible to realize a sensor configuration that can ensure flexibility (versatility) in concentration measurement, and as a result, it becomes possible to further improve the measurement accuracy and suppress the decrease in measurement sensitivity.

(l) In the present embodiment, the electrochemical sensor system including the electrochemical sensor 1 includes first to sixth circuits in addition to the electrochemical sensor 1, so that each of the electrochemical sensors 1 Each of the electrodes 21, 22, 23 is adapted to be selectively switched to function as a working electrode, a counter electrode or a reference electrode.
Therefore, according to the electrochemical sensor system of the present embodiment, not only the working electrode and the counter electrode, but also the reference electrode can respond to selection switching of each function, and as a result, further measurement can be performed. It becomes possible to improve the accuracy and suppress the decrease in measurement sensitivity.

<Modifications, etc.>
Although the first embodiment and the second embodiment have been described above, the technical scope of the present disclosure is not limited to the contents of each of the above-described embodiments, and can be variously changed without departing from the gist thereof. be.

(circuit configuration)
For example, in each of the above-described embodiments, in the electrochemical sensor system, the case where the measurement device 2 includes the selection circuit 54 was taken as an example, but a plurality of circuits (for example, the first circuit 52 and the second circuit 53, or the 1 circuit to 6th circuit), the selection circuit 54, such as a switch circuit, must be used if the O ₃ concentration in the ozone water, which is the test liquid, is measured. You don't have to. That is, alternative selection of a plurality of circuits may not depend on the selection circuit 54 .

(concentration measurement)
Further, for example, in each of the above-described embodiments, the case where LSV measurement is performed when measuring the O ₃ concentration in ozone water has been exemplified, but the present invention is not necessarily limited to this, and cyclic voltammetry (CV ) measurement, chronoamperometric measurement, or a method of applying a constant potential and measuring a current value at a predetermined timing.

Further, for example, in each of the above-described embodiments, the sample liquid is ozonated water, and the specific component whose concentration is to be measured is dissolved ozone in the ozonated water. However, the present invention can be applied to other types of test liquids and specific components as long as the concentration can be measured using an electrochemical reaction.

(selection switching)
Further, among the above-described embodiments, particularly in the first embodiment, which of the first BDD electrode 21 and the second BDD electrode 22 arranged in line symmetry functions as a working electrode or a counter electrode A case of performing selection switching is taken as an example. Regarding this point, it is conceivable to configure the following modified example.
In this modified example, the first BDD electrode 21 and the second BDD electrode 22 arranged in line symmetry are selectively switched to function as the working electrode or the reference electrode. Even with such a configuration, the configuration conditions of the working electrode and the counter electrode as viewed from the reference electrode are the same before and after the selection switching, so it is possible to obtain the effects described in the first embodiment.

In other words, the present disclosure also includes the technical ideas described below.
In one aspect of the present disclosure,
An electrochemical sensor used to measure the concentration of a specific component in a test solution,
comprising at least three electrodes disposed on the same substrate;
At least two of the three electrodes are diamond electrodes having the same structure and shape,
each of the two electrodes functions as either a working electrode or a reference electrode, and one of the three electrodes other than the two electrodes functions as a counter electrode;
An electrochemical sensor is included in which the two electrodes are arranged at positions symmetrical about a virtual line passing through a predetermined electrode reference point of the one electrode as an axis of symmetry.
Also, in another aspect of the present disclosure,
an electrochemical sensor according to one aspect of the above;
a first circuit for causing one of the two electrodes in the electrochemical sensor to function as a working electrode and the other as a reference electrode;
a second circuit that causes the one electrode to function as a reference electrode and the other electrode to function as a working electrode;
An electrochemical sensor system configured to select either the first circuit or the second circuit to measure the concentration of the specific component in the test liquid is included.

In addition, as in the above modification, it is conceivable to select and switch which of the first BDD electrode 21 and the second BDD electrode 22 to function as a counter electrode or a reference electrode. , the third BDD electrode 23 fixedly functions as a working electrode. If the working electrode is fixed, the effect of selective switching described in the first embodiment is not necessarily obtained. Therefore, regarding the selective switching of the electrode functions, at least the functions of the working electrode and the counter electrode can be exchanged as described in the first embodiment, or the functions of the working electrode and the reference electrode can be exchanged as in the above modified example. Preferably, they are interchangeable or the respective functions of the working, counter and reference electrodes are interchangeable as described in the second embodiment.

(Number of electrodes)
Further, for example, in each of the above-described embodiments, the case in which the three electrodes 21, 22, and 23 are arranged on the substrate 10 was taken as an example, but the present invention is not necessarily limited to this. Four or more electrodes may be arranged.
FIG. 14 is an explanatory diagram (Part 1) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure. FIG. 15 is an explanatory diagram (Part 2) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure.
14 or 15, the electrode group 20 arranged on the substrate 10 is composed of four BDD electrodes. In the case of such an arrangement mode, for example, a combination of three electrodes is extracted from the electrode group 20, and each electrode constituting the combination is selectively switched as described in the first embodiment or the second embodiment. It is possible to implement an operation in which the combination is appropriately changed as necessary. In that case, for the combination of the three electrodes, extract so that the conditions (circuits) at the time of measurement are equivalent (the positional relationship of each electrode is the same or symmetrical arrangement), that is, so that the combination is equivalent Extraction is desirable. Further, for example, for at least one of the working electrode, the counter electrode, or the reference electrode, the function is realized by a plurality of electrodes, and then selection switching as described in the first embodiment or the second embodiment is performed. It becomes possible to implement an operation such as
That is, as long as the electrode group 20 arranged on the substrate 10 is composed of at least three electrodes, the technical idea according to the present disclosure can be applied.

(Electrode arrangement)
Further, for example, in each of the above-described embodiments, the case in which the three electrodes 21, 22, and 23 are arranged on the same surface of the substrate 10 was taken as an example, but the invention is not necessarily limited to this, and each Electrodes 21 , 22 , 23 may be arranged on different sides of substrate 10 .

FIG. 16 is an explanatory diagram (Part 3) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure.
In the arrangement shown in FIG. 16, one electrode 23 is arranged on one surface (for example, the upper surface) of a flat substrate 10, and two electrodes 21 and 22 are arranged on the other surface (for example, the lower surface). Even with such an electrode arrangement, the two electrodes 21 and 22 can be symmetrically arranged as viewed from the electrode 23 . Further, depending on the thickness of the substrate 10, etc., it is also possible to set the electrodes 21, 22, 23 in a three-fold symmetrical positional relationship.

FIG. 17 is an explanatory diagram (part 4) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure.
In the arrangement mode shown in FIG. 17, three electrodes 21, 22, and 23 are dispersedly arranged on each of the three side surfaces of the substrate 10 in the shape of a quadrangular prism. Even with such an electrode arrangement, the two electrodes 21 and 22 can be symmetrically arranged as viewed from the electrode 23 . Further, depending on the cross-sectional size of the substrate 10, etc., it is possible to set the positions of the electrodes 21, 22, and 23 in three-fold symmetry.

FIG. 18 is an explanatory diagram (No. 5) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure.
In the arrangement shown in FIG. 18, three electrodes 21, 22, and 23 are dispersedly arranged on each of the three wall surfaces forming the inner surface of the substrate 10 in the shape of a quadrangular prism with one side open. Even with such an electrode arrangement, the two electrodes 21 and 22 can be symmetrically arranged as viewed from the electrode 23 . Further, depending on the cross-sectional size of the substrate 10, etc., it is possible to set the positions of the electrodes 21, 22, and 23 in three-fold symmetry.

FIG. 19 is an explanatory diagram (No. 6) schematically showing a modification of the electrode arrangement in the electrochemical sensor according to the present disclosure.
In the arrangement mode shown in FIG. 19, after arranging three electrodes 21, 22, 23 on the same surface of a flat substrate 10, the substrate 10 is formed into a desired cross-sectional shape (for example, a U-shaped cross section). so that the electrodes 21, 22, 23 are arranged on different planes. Even with such an electrode arrangement, the two electrodes 21 and 22 can be symmetrically arranged as viewed from the electrode 23 . Further, depending on the cross-sectional shape of the substrate 10 after bending, the electrodes 21, 22, and 23 can be arranged in a three-fold symmetrical positional relationship.

(Specific configuration example)
Here, one specific configuration example of the electrochemical sensor according to the present disclosure is illustrated in FIGS. 20 and 21. FIG.

FIG. 20 is a perspective view showing a specific configuration example of an electrochemical sensor according to the present disclosure.
The electrochemical sensor 1 of the illustrated example has three electrodes 21, 22, and 23 on the same surface of the substrate 10 arranged at three-fold symmetrical positions, and two of them are in a line-symmetrical relationship. Each electrode 21, 22, 23 is arranged in the . In addition, on the substrate 10, terminal portions 36 electrically connected to the electrodes 21, 22, 23 via the wirings 31, 32, 33 are provided on the edge side opposite to the side on which the electrodes 21, 22, 23 are arranged. , 37 and 38 are provided, and the wirings 31, 32 and 33 establishing electrical continuity are covered with a waterproof member 40. As shown in FIG.

21 is a six-sided view of the electrochemical sensor of FIG. 20. FIG. 21, (a) is a plan view, (b) is a front view, (c) is a bottom view, (d) is a rear view, (e) is a right side view, and (f) is a left side view, respectively. showing.

<Preferred Embodiment of the Present Disclosure>
Preferred aspects of the present disclosure will be added below.

(Appendix 1)
According to one aspect of the present disclosure,
An electrochemical sensor used to measure the concentration of a specific component in a test solution,
comprising at least three electrodes disposed on the same substrate;
At least two of the three electrodes are diamond electrodes having the same structure and shape,
The two electrodes are connected to the wiring provided on the substrate with the same structure using the same conductive bonding material,
The periphery of the junction between the two electrodes and the wiring is sealed with the same structure using the same insulating resin,
An electrochemical sensor is provided in which the two electrodes are arranged in line-symmetrical positions with respect to an imaginary line passing through a predetermined electrode reference point in the one electrode as an axis of symmetry.
Here, the diamond electrode has a structure in which a polycrystalline diamond film is laminated on a conductive base material,
The conductive base material of the diamond electrode is electrically connected to the wiring via the bonding material,
The wiring, the bonding material, and the conductive resin are not in contact with the diamond film surface.

(Appendix 2)
According to one aspect of the present disclosure,
An electrochemical sensor used to measure the concentration of a specific component in a test solution,
At least three or more electrodes arranged on the same substrate,
Three electrodes are selected from the three or more electrodes, and the electrodes to which the working electrode is assigned are different in the combination in which each electrode is assigned the function of either a working electrode, a counter electrode, or a reference electrode, and the subject Provided is an electrochemical sensor in which two or more combinations of equivalent electrochemical measurement circuits exist when measuring the concentration of a specific component in a liquid.

(Appendix 3)
According to one aspect of the present disclosure,
An electrochemical sensor used to measure the concentration of a specific component in a test solution,
comprising at least three electrodes disposed on the same substrate;
At least two of the three electrodes are diamond electrodes having the same structure and shape,
each of the two electrodes functions as either a working electrode or a counter electrode, and one of the three electrodes other than the two electrodes functions as a reference electrode;
An electrochemical sensor is provided in which the two electrodes are arranged in line-symmetrical positions with respect to an imaginary line passing through a predetermined electrode reference point in the one electrode as an axis of symmetry.

(Appendix 4)
According to another aspect of the present disclosure,
An electrochemical sensor used to measure the concentration of a specific component in a test solution,
comprising at least three electrodes disposed on the same substrate;
At least two of the three electrodes are diamond electrodes having the same structure and shape,
each of the two electrodes functions as either a working electrode or a reference electrode, and one of the three electrodes other than the two electrodes functions as a counter electrode;
An electrochemical sensor is provided in which the two electrodes are arranged in line-symmetrical positions with respect to an imaginary line passing through a predetermined electrode reference point in the one electrode as an axis of symmetry.

(Appendix 5)
According to yet another aspect of the present disclosure,
An electrochemical sensor used to measure the concentration of a specific component in a test solution,
comprising at least three electrodes disposed on the same substrate;
The three electrodes are composed of diamond electrodes having the same structure and shape,
each of said three electrodes functioning as either a working electrode, a counter electrode or a reference electrode;
An electrochemical sensor is provided in which the three electrodes are arranged at three-fold symmetrical positions with respect to a predetermined substrate reference point on the substrate.

(Appendix 6)
Preferably,
The electrochemical sensor according to any one aspect of Appendices 3 to 5 is provided, wherein the substrate is formed in a symmetrical planar shape.

(Appendix 7)
Preferably,
The electrochemical sensor according to any one of Appendices 3 to 5, wherein the specific component is dissolved ozone in the test liquid.

(Appendix 8)
According to one aspect of the present disclosure,
The electrochemical sensor according to Appendix 3;
a first circuit for causing one of the two electrodes in the electrochemical sensor to function as a working electrode and the other as a counter electrode;
a second circuit in which the one electrode functions as a counter electrode and the other electrode functions as a working electrode;
An electrochemical sensor system configured to select either the first circuit or the second circuit to measure the concentration of the specific component in the test liquid is provided.

(Appendix 9)
According to another aspect of the present disclosure,
The electrochemical sensor according to Appendix 4;
a first circuit for causing one of the two electrodes in the electrochemical sensor to function as a working electrode and the other as a reference electrode;
a second circuit that causes the one electrode to function as a reference electrode and the other electrode to function as a working electrode;
An electrochemical sensor system configured to select either the first circuit or the second circuit to measure the concentration of the specific component in the test liquid is provided.

(Appendix 10)
According to yet another aspect of the present disclosure,
The electrochemical sensor according to Appendix 5;
When the three electrodes in the electrochemical sensor are respectively a first electrode, a second electrode and a third electrode, the first electrode is the working electrode, the second electrode is the counter electrode, and the third electrode is referred to a first circuit functioning as an electrode;
a second circuit in which the first electrode functions as a counter electrode, the second electrode functions as a working electrode, and the third electrode functions as a reference electrode;
a third circuit in which the first electrode functions as a working electrode, the second electrode functions as a reference electrode, and the third electrode functions as a counter electrode;
a fourth circuit in which the first electrode functions as a counter electrode, the second electrode functions as a reference electrode, and the third electrode functions as a working electrode;
a fifth circuit in which the first electrode serves as a reference electrode, the second electrode serves as a working electrode, and the third electrode serves as a counter electrode;
a sixth circuit in which the first electrode serves as a reference electrode, the second electrode serves as a counter electrode, and the third electrode serves as a working electrode;
An electrochemical sensor system configured to select any one of the first circuit to the sixth circuit to measure the concentration of the specific component in the test solution is provided.

(Appendix 11)
Preferably,
The electrochemical sensor system according to any one aspect of Appendices 8 to 10 is provided, comprising: a selection control unit that performs selective switching of the plurality of circuits at preset periodic timings.

(Appendix 12)
Preferably,
12. The electrochemical sensor system according to appendix 11, wherein the timing is set every time detection is performed by one circuit from the start to the end of one concentration measurement.

(Appendix 13)
Preferably,
Acquiring a plurality of measured values obtained by each of the plurality of circuits, deriving one measured value based on the plurality of measured values, and using the one measured value to measure the concentration of the specific component in the test solution 13. There is provided an electrochemical sensor system according to clause 12, comprising a measurement manager for taking measurements for.

(Appendix 14)
Preferably,
There is provided the electrochemical sensor system according to appendix 11, wherein the timing is set to timing each time concentration measurement is performed once or multiple times.

(Appendix 15)
Preferably,
an energization control unit that energizes each electrode in the electrochemical sensor in a manner different from that used when measuring the concentration of the specific component in the test solution, and performs state recovery processing for each electrode. There is provided an electrochemical sensor system according to any one of clauses 8-10.

DESCRIPTION OF SYMBOLS 1... Electrochemical sensor 2... Electrochemical measuring apparatus 3... Computer apparatus 10... Support substrate (base material) 21... First BDD electrode 22... Second BDD electrode 23... Third BDD electrode 24... Electrode film 25 Conductive substrate 26, 26a, 26b, 26c Electrode reference point 27, 27a, 27b, 27c Virtual line 28 Substrate reference point 31, 32, 33 Wiring 51 Electricity Chemical measurement circuit 52 First circuit 53 Second circuit 54 Selection circuit 60 Control section 61 Selection control section 62 Measured value management section 63 Energization control section

Claims (11)

An electrochemical sensor used to measure the concentration of a specific component in a test solution,
comprising at least three electrodes disposed on the same substrate;
The three electrodes are composed of diamond electrodes having the same structure and shape,
each of said three electrodes functioning as either a working electrode, a counter electrode or a reference electrode;
The electrochemical sensor, wherein the three electrodes are arranged at three-fold symmetrical positions with respect to a predetermined substrate reference point on the substrate. The electrochemical sensor according to claim 1 , wherein the substrate is formed in a symmetrical planar shape. The electrochemical sensor according to claim 1 , wherein the specific component is dissolved ozone in the test liquid. An electrochemical sensor used for measuring the concentration of a specific component in a test solution, comprising at least three electrodes arranged on the same substrate, wherein at least two of the three electrodes are the same composed of diamond electrodes having the same structure and shape, each of said two electrodes functioning as either a working electrode or a counter electrode, and one of said three electrodes other than said two electrodes acting as a reference an electrochemical sensor functioning as an electrode, wherein the two electrodes are arranged at symmetrical positions with respect to an imaginary line passing through a predetermined electrode reference point in the one electrode as an axis of symmetry;
a first circuit for causing one of the two electrodes in the electrochemical sensor to function as a working electrode and the other as a counter electrode;
a second circuit in which the one electrode functions as a counter electrode and the other electrode functions as a working electrode;
with
An electrochemical sensor system configured to select either the first circuit or the second circuit to measure the concentration of the specific component in the test liquid. An electrochemical sensor used for measuring the concentration of a specific component in a test solution, comprising at least three electrodes arranged on the same substrate, wherein at least two of the three electrodes are the same composed of diamond electrodes having the same structure and shape, each of the two electrodes functions as either a working electrode or a reference electrode, and one of the three electrodes other than the two electrodes serves as a counter electrode; an electrochemical sensor functioning as an electrode, wherein the two electrodes are arranged at symmetrical positions with respect to an imaginary line passing through a predetermined electrode reference point in the one electrode as an axis of symmetry;
a first circuit for causing one of the two electrodes in the electrochemical sensor to function as a working electrode and the other as a reference electrode;
a second circuit that causes the one electrode to function as a reference electrode and the other electrode to function as a working electrode;
An electrochemical sensor system configured to select either the first circuit or the second circuit to measure the concentration of the specific component in the test liquid. an electrochemical sensor according to claim 1 ;
When the three electrodes in the electrochemical sensor are respectively a first electrode, a second electrode and a third electrode, the first electrode is the working electrode, the second electrode is the counter electrode, and the third electrode is referred to a first circuit functioning as an electrode;
a second circuit in which the first electrode functions as a counter electrode, the second electrode functions as a working electrode, and the third electrode functions as a reference electrode;
a third circuit in which the first electrode functions as a working electrode, the second electrode functions as a reference electrode, and the third electrode functions as a counter electrode;
a fourth circuit in which the first electrode functions as a counter electrode, the second electrode functions as a reference electrode, and the third electrode functions as a working electrode;
a fifth circuit in which the first electrode serves as a reference electrode, the second electrode serves as a working electrode, and the third electrode serves as a counter electrode;
a sixth circuit in which the first electrode serves as a reference electrode, the second electrode serves as a counter electrode, and the third electrode serves as a working electrode;
An electrochemical sensor system configured to select any one of the first circuit to the sixth circuit to measure the concentration of the specific component in the test liquid. 7. The electrochemical sensor system according to any one of claims 4 to 6, further comprising a selection control section that performs selective switching of a plurality of circuits at preset periodic timings. 8. The electrochemical sensor system according to claim 7 , wherein the timing is set every time detection by one circuit is performed from the start to the end of one concentration measurement. Acquiring a plurality of measured values obtained by each of the plurality of circuits, deriving one measured value based on the plurality of measured values, and using the one measured value to measure the concentration of the specific component in the test solution 9. The electrochemical sensor system according to claim 8 , further comprising a measured value management section for determining a measured value for. 8. The electrochemical sensor system according to claim 7, wherein the timing is set to timing each time concentration measurement is performed once or multiple times. an energization control unit that energizes each electrode in the electrochemical sensor in a manner different from that used when measuring the concentration of the specific component in the test solution, and performs state recovery processing for each electrode. An electrochemical sensor system according to any one of claims 4 to 6 .

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