Analysis device

Abstract

To solve the problem in which: the relationship between a channel wall and an electrode in a porous substrate makes it difficult to achieve both the adhesion between the electrode and the substrate and prevention of electrode cracks caused by deformation of the substrate in a high humidity environment ot the like, and ion concentration measurement may not be accurately carried out without the achievement.SOLUTION: In an electrode part taking a contact of an external measuring instrument, at least part of an electrode is formed inside a porous substrate, and a channel wall is always present on a straight line on which the electrode is present.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an analytical device in which electrodes are formed using flow channels in a porous substrate. [Background technology]

[0002] In recent years, the development of microanalysis chips that can perform biochemical analysis efficiently (trace amounts, quickly, and simply) within a single chip using micro-sized fine flow channels has attracted attention in a wide range of fields. The wide range of fields includes not only biochemical research but also medicine, drug discovery, healthcare, the environment, and food. Among them, paper-based paper microanalysis chips have many advantages over conventional devices, such as light weight, low cost, no need for a power source, and high disposability. For this reason, they are expected to be used in medical activities in developing countries and remote areas where medical facilities are not well equipped, as well as at disaster sites, and as testing devices at airports where the spread of infectious diseases must be stopped at the border. In addition, because they are inexpensive and easy to use, they are attracting attention as healthcare devices that allow individuals to manage and monitor their own health conditions.

[0003] As an example of a paper microanalysis chip, Patent Document 1 describes a configuration in which an electrode is formed on a porous substrate so as to straddle a hydrophobic flow path wall made of wax. In this configuration, one end of the electrode reacts with a specimen in the flow path to form a predetermined potential, and a measuring device is connected to the other end of the electrode to perform measurement. The chip is composed of two electrodes: a reference electrode that shows a fixed potential due to a reference liquid, and an ion-selective electrode that shows a potential according to the ion concentration of the specimen, and the ion concentration of the specimen can be measured by measuring the potential difference between the two electrodes.

[0004] Non-Patent Document 1 also describes an analytical chip that can measure the ion concentration of a sample by measuring the potential difference between two electrodes, but in this document, the electrodes that serve as the contact points for the measuring device are formed on a hydrophobic flow path wall made of wax. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2016 / 033438 [Non-patent literature]

[0006] [Non-Patent Document 1] Nipapan Ruecha, Orawon Chailapakul, Koji Suzuki and Daniel Citterio “Fully Inkjet-Printed Paper-Based Potentiometric Ion-Sensing Devices” Analytical chemistry August 29, 2017 Published, 89, pp.10608-10616 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the method described in Patent Document 1, for example, if the analysis chip is placed in a high humidity environment, the paper may absorb moisture and deform, causing cracks in the electrodes. If cracks occur in the electrodes, they will naturally affect the measured potential, making it difficult to measure the ion concentration correctly.

[0008] In addition, in the method described in Non-Patent Document 1, the electrodes that serve as the contact points of the measuring device are formed on the flow path walls, which may result in poorer adhesion than when they are formed on a porous surface. If the electrodes have poor adhesion, they may peel off due to pressure or friction to establish the measurement contact points, and if the electrodes peel off, this will naturally affect the measured potential value, making it difficult to measure the ion concentration correctly. [Means for solving the problem]

[0009] porous substrate, A flow path wall formed by filling the pores of the porous substrate with a hydrophobic material; and electrode An analytical device comprising: When viewed from above, the analytical device has a first region and a second region separated by the flow path wall; the electrode is formed across the first region, the flow path wall and the second region; A straight line passing through the electrode necessarily intersects with the flow path wall; moreover, In the second region, the electrode is formed at least in part within the porous substrate. Analytical devices. to provide. Effect of the Invention

[0010] As described above, according to one aspect of the present disclosure, a microanalysis chip can be provided that has high adhesion between the electrode and the porous substrate while suppressing cracks in the electrode due to deformation of the substrate, thereby enabling stable potential measurement. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a top view of the analytical device M1 after the flow path walls 11 are formed (before the electrodes are formed) in Example 1. [Diagram 2] 1A is a top view of the working electrode side of the analytical device M1 in Example 1. FIG. 1B is a cross-sectional view of the analytical device M1 in Example 1 taken along dashed line D1. [Diagram 3] 1A is a top view of an analytical device M1 after forming various electrodes in Example 1. FIG. 1B is a cross-sectional view of the analytical device M1 in Example 1 taken along a dashed line D2. [Figure 4] 1(a) is a top view of an analytical device M2 after formation of various electrodes in Comparative Example 1. FIG. 1(b) is a perspective view of the analytical device M2 after formation of various electrodes in Comparative Example 1. [Diagram 5] FIG. 13 is a diagram showing the results of measuring the electric potential of a chip with and without cracks. [Figure 6]1A is a top view of an analytical device M3 of Comparative Example 2. FIG. 1B is a cross-sectional view of the analytical device M3 of Comparative Example 2 taken along a dashed line D6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments are merely examples, and the present invention is not limited to the contents of the embodiments. In addition, in each of the following drawings, components that are not necessary for the description of the embodiments are omitted from the drawings.

[0013] An embodiment of the present invention provides an analytical device having a porous substrate, a flow path wall formed by filling the pores of the porous substrate with a hydrophobic material, and an electrode, the analytical device having a first region and a second region separated by the flow path wall when viewed from above, the electrode being formed across the first region, the flow path wall, and the second region, and a straight line passing through the electrode necessarily intersects with the flow path wall, and further, in the second region, at least a portion of the electrode is formed inside the porous substrate.

[0014] The first region may be a region into which the sample permeates. The second region may be a region for connecting to an external measuring device, and may be connected to the external measuring device via a portion of the electrode present in the second region. The analytical device may have a first electrode and a second electrode as electrodes, the first electrode being a reference electrode, and the second electrode being a working electrode.

[0015] [Example 1] <Substrate / flow path> The base material of the analytical device M1 will be described with reference to Fig. 1. Fig. 1 is a simplified top view of the analytical device M1 before various electrodes are formed.

[0016] In this embodiment, filter paper was used as the porous substrate S1. The material of the filter paper used was cellulose, with a thickness of 100 μm and a porosity of 50%. Such filter paper has good hydrophilicity due to the capillary phenomenon caused by the fine gaps between the cellulose fibers, and functions as a flow path through which liquids can smoothly penetrate. Naturally, the porous substrate S1 is not limited to filter paper as long as it functions as a flow path, and may be paper such as ordinary paper, fine paper, watercolor paper, Kent paper, and synthetic paper, as well as synthetic resin porous films, fabrics, and textile products. The porosity can be appropriately selected according to the purpose, but is preferably 20% or more and 90% or less. If the porosity exceeds 90%, the strength of the substrate may not be maintained, and if it is less than 20%, the permeability of the sample liquid may be poor. The porosity (%) is calculated by the formula "porosity (%) = (true density - apparent density) / true density x 100".

[0017] A hydrophobic resin was permeated into a portion of the porous substrate S1 as a hydrophobic material to form a flow path wall 11 having a vertical width H1 = 14 mm and a horizontal width L1 = 22 mm. The flow path wall 11 was formed by electrophotographically printing a hydrophobic resin as a toner and melting and permeating the resin by heating according to the method described in JP 2021-37612 A. As a hydrophobic material for forming the flow path wall, a hydrophobic resin is preferable, and as the hydrophobic resin, polyester resin, vinyl resin, acrylic resin, styrene acrylic resin, polyethylene, polypropylene, polyolefin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, etc. are used without any particular limitation. As a method for arranging the hydrophobic resin, in addition to using an electrophotographic device, a method using an inkjet printer, a method of permeating wax with a wax printer, a method of permeating resin with screen printing, etc. may be used, and further a combination of multiple methods may be used.

[0018] The region inside the flow path wall 11 includes a region that is not permeated with the hydrophobic resin that becomes the flow path wall, that is, a region that does not have a flow path wall. The analytical device of this embodiment has at least a first region 101 and a second region 102 as a region that does not have a flow path wall. The first region 101 is a region into which a sample permeates due to the capillary phenomenon caused by the porosity of the porous substrate S1. In this embodiment, the first region 101 includes a working electrode arrangement portion S1b in which a working electrode is arranged, a reference electrode arrangement portion S1c in which a reference electrode is arranged, a dispensing portion S1d located between the working electrode arrangement portion S1b and the reference electrode arrangement portion S1c, and a flow path S1f having a width of 2 mm that connects the dispensing portion S1d to the working electrode arrangement portion S1b and the reference electrode arrangement portion S1c. However, the first region 101 does not necessarily have to include all of these, and may also include other portions and flow paths. In this embodiment, the working electrode arrangement portion S1b and the reference electrode arrangement portion S1c are squares each having a size of 6 mm on each side, and the dispensing portion S1d is a circle having a diameter of 3 mm. The size, shape, etc. of each arrangement portion and the flow path are not limited to this. Next, the second region 102 is a region that does not have a flow path wall and is a place where contact with an external measurement device is made during measurement, and the sample does not necessarily penetrate into the second region 102. In this embodiment, the second region has a working electrode contact portion S1a and a reference electrode contact portion S1e, and each contact portion is a square having a size of 4 mm on each side. In this embodiment, the working electrode contact portion S1a and the reference electrode contact portion S1e are separated by a flow path wall and are not connected to each other, but they may be connected to each other. On the other hand, the first region 101 and the second region 102 are not connected to each other, and are formed separated by a flow path wall 11. Details of the contacts will be described later together with the explanation of the electrodes.

[0019] Hereinafter, the formation of the working electrode of the analytical device M1 will be described with reference to FIG. FIG. 2(a) is a top view of the analytical device M1 after the working electrode 31 is formed, and FIG. 2(b) shows a cross section of the dashed line portion D1.

[0020] <Working electrode> The working electrode 31 is an electrode having a shape consisting of a square shape of 4 mm on each side that fits in the working electrode placement portion S1b and a rectangle of 1 mm width and 6 mm length that extends from the working electrode placement portion S1b to the working electrode contact portion S1a. The material of the working electrode 31 is Cl. - Although Ag is used as the electrode for detecting the ion concentration, the material is not limited to this, and any material and configuration that functions as a working electrode may be used. Furthermore, the working electrode 31 may be formed with an ion selective membrane in addition to the electrode.

[0021] The working electrode 31 was formed using a screen printer DP-320 manufactured by Newlong Co., Ltd. The printing was performed using a #200 plate, and drying was performed at 80°C for 10 minutes. However, the method of forming the working electrode 31 is not limited to this. The electrode may be Ag / AgCl, PEDOT / PSS, or an electrode using carbon, without any particular limitation. For the preparation of an electrode using Ag / AgCl or carbon, refer to, for example, US Patent Application Publication No. 2016033438. For the preparation of an electrode using PEDOT (poly(3,4-ethylenedioxyphene)) / PSS (poly(4-styrenesulfonate)), refer to, for example, Non-Patent Document 1.

[0022] In addition, when the working electrode 31 has an ion selective membrane, the ion selective membrane may be any commonly used one that is sensitive to the target ion and has sufficient selectivity for interfering ions. The ion selective membrane includes a compound having ion selectivity. There is no particular limitation on the compound having ion selectivity, but preferred examples include ionophores and anion removers that show ion selectivity. An example of the ionophore is 12-crown 4-ether having a crown ether structure, and an example of the anion remover is sodium tetraphenylborate (NaTPB). Any known material may be used for the ion selective membrane, and examples of such materials can be found in, for example, pages 138 to 140 of "I want to measure ion concentration with an electrode" by Dojindo Laboratories, Ltd.

[0023] The ion-selective membrane may contain a polymeric compound to maintain its structure. Examples of the polymeric compound include polyvinyl chloride (abbreviation: PVC) and a copolymer of vinyl chloride and vinyl acetate. The ion-selective membrane may contain a plasticizer to make the ionophore operable. Although known plasticizers can be used, lipophilic ion exchange materials that act as lipophilic ion exchange in the ion-selective membrane are more preferable. Examples of known materials include 2-nitrophenyl octyl ether (abbreviation: NPOE), bis(2-ethylhexyl) sebacate (abbreviation: DOS), bis(2-ethylhexyl) adipate (abbreviation: DOA), and di-n-octylphenyl phosphonate (abbreviation: DOPP).

[0024] As shown in FIG. 2(b), the working electrode 31 formed as described above is partially formed inside the porous substrate in the first region 101 and the second region 102. That is, in the working electrode arrangement portion S1b which is the first region 101 and the working electrode contact portion S1a which is the second region 102, a part of the electrode penetrates into the pores of the porous substrate S1, and the electrode is also formed inside the porous substrate S1. As a result, not only is the working electrode arrangement portion S1b which is the first region 101 properly in contact with the sample, but the working electrode contact portion S1a which is the second region 102 can increase the adhesion between the electrode and the porous substrate S1 due to the anchor effect. Therefore, by making the contact portion with the external measuring device the working electrode contact portion S1a which is the second region 102, an electrode that is difficult to peel off even when subjected to pressure or friction by the measurement contact can be formed. In order to obtain this effect, the porous substrate needs to be exposed on at least a part of the surface of the second region 102.

[0025] In this embodiment, the second region 102, that is, the working electrode contact portion S1a and the reference electrode contact portion S1e, are configured to include nothing inside the porous substrate S1, but as long as at least a part of the porous substrate is exposed to the surface, a desired material may be placed inside the porous substrate at these contact portions to adjust the physical properties of the substrate. For example, in order to increase the rigidity of the working electrode contact portion S1a, a predetermined resin may be impregnated into the porous substrate, and it is also possible to improve the ease of contact with an external measuring device. In this case, the type, shape, and amount of the material formed in the porous substrate S1 can be freely selected within the range in which the pores of the porous substrate S1 are exposed to the surface.

[0026] Hereinafter, the formation of the reference electrode of the analytical device M1 will be described with reference to FIG. FIG. 3(a) is a top view of the analytical device M1 after the working electrode 31 is formed, and FIG. 3(b) shows a cross section of the dashed line portion D2.

[0027] <Reference electrode> The reference electrode 32 is formed across the reference electrode placement portion S1c, which is the first region 101, to the reference electrode contact portion S1e, which is the second region 102, and has a rectangular shape of 1 mm x 10 mm. The reference electrode 32 reacts with a sample that has permeated the flow path in the reference electrode placement portion S1c, which is the first region 101, like the working electrode 31, and can make contact with an external measuring device in the reference electrode contact portion S1e, which is the second region 102. By making the width as small as 1 mm, when the electrolyte layer 41 described later is applied, it becomes easier to place the electrolyte layer 41 on the porous base material of the reference electrode placement portion S1c including the back side of the reference electrode 32.

[0028] Ag / AgCl was used as the material for the reference electrode 32. By using Ag / AgCl, an equilibrium reaction according to the following formula (1) occurs in the aqueous solution, so that the Cl around the reference electrode 32 - A stable potential can be obtained when the concentration is stable.

number

[0029] The reference electrode 32 was applied to the reference electrode placement portion S1c using a screen printer DP-320 manufactured by Newlong Co., Ltd. A #200 plate was used for printing, and drying was performed at 80° C. for 10 minutes. However, the method for producing the electrode is not limited to this, and any method can be used as described in the section on the working electrode.

[0030] In addition, in the reference electrode contact portion S1e, which is the second region, a part of the reference electrode 32 is formed inside the porous substrate S1, similarly to the working electrode contact portion S1a. Therefore, the reference electrode 32 is less likely to peel off.

[0031] <Electrolyte layer> When the sample introduced into the dispensing section S1d permeates into the reference electrode placement section S1c, the electrolyte layer 41 dissolves with the water in the sample, and - is the saturated concentration. - When the concentration of KCl reaches a saturated concentration, the potential of the reference electrode 32 becomes stable. For this reason, in this embodiment, KCl is used as the material of the electrolyte layer 41. KCl was selected because it is easily dissolved in water, and the diffusion rates of K ions and Cl ions are almost equal, making it difficult for a liquid junction potential to occur. Naturally, the material of the electrolyte layer 41 is not limited to this, and any material that can stabilize the potential of the reference electrode 32 may be used, for example, NaCl.

[0032] The electrolyte layer 41 was applied using Biospot manufactured by Microjet Co., Ltd. The solution was prepared by dissolving KCl in pure water to a concentration of 16% by mass. The droplet size was 6 nL / droplet, the frequency was 10 Hz, and the pitch was 300 μm in both the vertical and horizontal directions, and the amount of KCl was adjusted by applying three times. The amount of KCl can be stabilized by adjusting the amount of KCl to saturate the KCl with respect to the amount of specimen that permeates the reference electrode placement portion S1c. Therefore, the amount of application is not limited to this as long as there is an amount of KCl that is sufficient to saturate the KCl. Note that the viscosity of the KCl aqueous solution is lower than that of the solution of the ion selective membrane 21, and by increasing the droplet size and increasing the frequency, the KCl aqueous solution attached to the porous substrate S1 diffuses within the porous substrate S1 before volatilizing, and KCl can be arranged on the back side of the reference electrode 32 as shown in FIG. 3(b). As a result, when the specimen permeates, the Cl around the reference electrode 32 is saturated. - The concentration becomes stable, and the potential of the reference electrode 32 becomes stable, i.e., the reference electrode functions more stably.

[0033] In addition, in the analytical device M1, a straight line passing through the electrodes always passes through the flow path wall. For example, in the dashed line portion D3 in FIG. 3(a), the flow path wall 11 is formed in a location other than the working electrode contact portion S1a and the reference electrode contact portion S1e. Similarly, in the dashed line portion D4 taken at a different angle, the straight line passes through the flow path wall together with the electrodes. With this configuration, deformation of the porous substrate S1 is suppressed even when placed in a high humidity environment, and cracks in the electrodes can be suppressed.

[0034] [Comparative Example 1] An analytical device M2 of Comparative Example 1 in comparison with the analytical device M1 will be described with reference to FIG. Fig. 4(a) is a simplified top view of the analytical device M2, and Fig. 4(b) is a simplified perspective view of the analytical device M2. Since the configuration of the analytical device M2 is similar to that of the analytical device M1 except for the shape of the flow path walls, the same members are given the same reference numerals, and the description of similar parts is omitted.

[0035] As shown in Fig. 4(a), the flow path wall 51 of the analytical device M2 has a hydrophobic flow path wall only in the upper part of the paper in a range of vertical width H2 = 7 mm of the analytical device M2. And, in the range indicated by H3 corresponding to the second region etc. of the analytical device M1, that is, the range corresponding to the lower part of the paper, there is no flow path wall. Therefore, at the position of the dashed line portion D5, there is an electrode but no flow path wall. In other words, when the analytical device M2 is viewed from above, there is a straight line that passes through the electrode but not through the flow path wall, and the straight line that passes through the electrode does not necessarily intersect with the flow path wall.

[0036] Here, a case where the analytical device M2 is placed in a high humidity environment will be described. In a high humidity environment, water is adsorbed to the porous substrate S1 made of highly hydrophilic cellulose, causing the paper fibers to swell and the porous substrate S1 to undulate and deform. Figure 4(b) shows how the working electrode 31 and reference electrode 32 formed on the porous substrate S1 are also deformed due to the influence of the deformation of the porous substrate S1. When such deformation occurs, the electrodes cannot withstand the stress and cracks occur, and when potential measurements are performed using an external measuring device, the cracks can cause poor conductivity and increased load resistance, which can prevent proper ion concentration measurements.

[0037] At this time, where the flow path wall 51 is present, water adsorption does not occur due to the hydrophobicity of the flow path wall 51, and deformation due to swelling of the porous substrate S1 does not occur. Furthermore, the presence of the flow path wall 51 increases rigidity compared to the case where only the porous substrate S1 is present, so deformation of the flow path surrounded by the flow path wall 51 is suppressed. In other words, on a straight line where there is no flow path wall, such as the dashed line portion D5, deformation of the porous substrate S1 may be caused by swelling due to water adsorption, and if an electrode is present there, a crack in the electrode may prevent correct measurement.

[0038] In fact, FIG. 5 shows the potential difference between the working electrode and the reference electrode when a sample in which 100 mM NaCl is dissolved is dispensed into the dispensing section S1d of the analytical device M2. The potential measurement was performed using Bio-Logic VSP-300 to measure the potential difference between the working electrode contact section S1a and the reference electrode contact section S1e. The analytical devices used in the measurement were a total of three chips (analytical devices) with no cracks in the electrodes (crack-free chips 1 and 2) and one chip with a crack (cracked chip 1). As shown in FIG. 5, the chip with no cracks shows almost the same potential after 10 seconds, for example, but the chip with a crack has a significantly different potential, and it can be seen that the ion concentration of the sample cannot be measured correctly even if an attempt is made to measure it.

[0039] [Comparative Example 2] Next, an analytical device M3 of Comparative Example 2 in comparison with the analytical device M1 will be described with reference to FIG.

[0040] Fig. 6(a) is a simplified top view of analytical device M3, and Fig. 6(b) shows a cross section of dashed line portion D6. Since analytical device M3 has the same configuration as analytical device M1 except for the shape of the flow path wall, the same members are given the same reference numerals and the description of similar parts is omitted.

[0041] 6(a), the analytical device M3 has a flow path wall 61 with a vertical width H1=14 mm, like the analytical device M1, but also has flow path walls 61 at the working electrode contact portion S1a and the reference electrode contact portion S1e. In other words, it does not have a second region. With this configuration, the analytical device M3 is unlikely to deform in the porous substrate S1 even if it is placed in a high humidity environment like the analytical device M2 described above, and no cracks are generated in the electrodes.

[0042] On the other hand, as shown in FIG. 6(b), the analytical device M3 does not have a second region, and naturally, the working electrode does not have a portion formed inside the porous substrate in the second region. At the working electrode contact portion S1a and the reference electrode contact portion S1e, the working electrode 31 and the reference electrode 32 are formed on the upper layer of the flow path wall 61. That is, the pores of the porous substrate S1 are filled with the flow path wall 61, and the electrodes are formed on the pores. Therefore, the working electrode 31 and the reference electrode 32 do not obtain the anchor effect described above with respect to the substrate, and the adhesion is reduced. Then, when the working electrode 31 and the reference electrode 32 are subjected to pressure or friction due to the measurement contact with the external measurement device during potential measurement, they may peel off from the porous substrate S1, and the potential measurement may not be performed stably.

[0043] The results of the above examples and comparative examples are shown in the table below. [Table 1]

[0044] In this embodiment, the case where the analytical device is placed in a high humidity environment has been described as an example of deformation of the substrate. However, the situation is not limited to this, and for example, in the process of producing an analytical device, a similar phenomenon occurs when a solvent or the like penetrates into the porous substrate S1 in a cleaning or pretreatment process after forming an electrode, so that the configuration of this embodiment can perform stable potential measurement even in such a case.

[0045] As described above, by having an electrode spanning a second region in which the porosity is exposed on the surface and a first region separated by a flow path wall, and by having a configuration in which a flow path wall is always present on the straight line in which the electrode is present, it is possible to increase the adhesion between the electrode and the substrate while suppressing electrode cracks due to substrate deformation.

[0046] In other words, this configuration makes it possible to provide an analytical device that can stably measure potential.

[0047] The embodiments of the present invention include the following configurations. (Configuration 1) porous substrate, A flow path wall formed by filling the pores of the porous substrate with a hydrophobic material; and electrode An analytical device comprising: When viewed from above, the analytical device has a first region and a second region separated by the flow path wall; the electrode is formed across the first region, the flow path wall and the second region; A straight line passing through the electrode necessarily intersects with the flow path wall; moreover, In the second region, the electrode is at least partially formed within the porous substrate. Analytical devices. (Configuration 2) The first region is a region permeated with an analyte. 2. The analytical device according to configuration 1. (Configuration 3) The second region is a connection region, and is connected to an external measurement device via a portion of the electrode that is present in the second region. An analytical device according to configuration 1 or 2. (Configuration 4) The electrodes include a first electrode and a second electrode, the first electrode is a reference electrode; The second electrode is a working electrode. An analytical device according to any one of configurations 1 to 3. [Explanation of symbols]

[0048] M1 Analysis Device M2 Analysis Device M3 Analytical Device S1 Porous base material S1a Working electrode contact part S1b Working electrode arrangement part S1c Reference electrode placement area S1d Dispensing unit S1e Reference electrode contact section 11 Channel Wall 51 Channel Wall 61 Channel Wall 31 Working electrode 32 Reference electrode 41 Electrolyte layer 101 First region 102 Second region

Claims

1. porous substrate, A flow path wall formed by filling the pores of the porous substrate with a hydrophobic material; and electrode An analytical device comprising: When viewed from above, the analytical device has a first region and a second region separated by the flow path wall; the electrode is formed across the first region, the flow path wall and the second region; A straight line passing through the electrode necessarily intersects with the flow path wall; moreover, In the second region, the electrode is at least partially formed within the porous substrate. Analytical devices.

2. The first region is a region permeated with an analyte. The analytical device according to claim 1 .

3. The second region is a connection region, and is connected to an external measurement device via a portion of the electrode that is present in the second region. The analytical device according to claim 1 or 2.

4. The electrodes include a first electrode and a second electrode, the first electrode is a reference electrode; The second electrode is a working electrode. The analytical device according to claim 1 or 2.

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