Analysis device and inspection method using analysis device

Abstract

According to the present invention, it is possible to provide an analysis device that is capable of maintaining the stability of a dispensation specimen in a dispensing part while protecting the surface, and is capable of performing stable measurement. The analysis device has a hydrophilic or porous flow path region surrounded by a hydrophobic flow path wall provided inside of or on a substrate, said analysis device being characterized in that: the surface of the analysis device is provided with a dispensing part from which a specimen is dispensed, a region B which is provided so as to surround the dispensing part and is covered by a regulating member that is not penetrated by the specimen, and a region A which is formed to be adjacent to the side of the region B that does not face the dispensing part of the region B; a step is provided in the thickness direction of the analysis device at the boundary between the region A and the region B; and the step satisfies the requirement of either (i) or (ii). (i) The region A is lower than the region B. (ii) The region A is higher than the region B, and the region A is covered by a regulating member that is not penetrated by the specimen.

Description

Analytical device and testing method using the analytical device

[0001] The present invention relates to an analytical device having a hydrophilic or porous flow channel region surrounded by hydrophobic flow channel walls provided in or on a substrate.

[0002] In recent years, analytical devices that utilize small-sized microchannels to efficiently perform biochemical analyses on a single chip have attracted attention in a wide range of fields, including biochemical research, medicine, drug discovery, healthcare, the environment, and food.

[0003] In the early 1990s, photolithography and molds were used to form micrometer-sized fine channels on glass or silicon, and analytical devices were developed that could perform sample pretreatment, stirring, mixing, reaction, and detection on a single chip. As a result, miniaturization of testing systems, rapid analysis, and reduction of specimens and waste liquids were realized.

[0004] Electrochemical analysis, which measures the potential between electrodes immersed in the sample to be analyzed, is widely used in fields such as medicine and the environment. Conventional electrochemical analysis is performed by technicians using sophisticated equipment, which limits the fields and resources available for measurement. Therefore, there is a need for inexpensive, easy-to-use, disposable electrochemical analysis devices for use in developing countries and depopulated areas with insufficient medical facilities, medical care at disaster sites, and airports where the spread of infectious diseases must be prevented at the border.

[0005] Non-Patent Document 1 proposes a filter paper-based measurement device for measuring Na and K ion concentrations. This device has a dispensing section for dispensing the sample. The dispensed sample permeates from the dispensing section into the working and reference electrode regions, electrically connecting the two electrodes and enabling potential difference measurement. To achieve a stable potential at the reference electrode, the device also deposits KCl ion crystals on the reference electrode. During measurement, KCl dissolves into the sample, maintaining a high concentration of Cl ions in the reference electrode region and achieving a stable reference electrode potential. Furthermore, an ion-selective membrane formed to cover the working electrode selects only the ions to be measured, allowing measurement to be performed without being affected by other ions.

[0006] Patent Literature 1 also discloses a method for measuring the concentration of a specific protein contained in a biological sample. A fluorescent substance is placed in a sensing area defined by a hydrophobic barrier formed on a paper substrate, and the concentration of the specific protein is measured by analyzing a fluorescent signal generated by reaction with the sample. It is stated that the sensing area defined by the hydrophobic barrier and the biological sample dispensing section may be the same area.

[0007] Furthermore, Patent Document 2 proposes a configuration in which the sensing area and the sample dispensing section are the same area in order to improve measurement sensitivity, and the sample dispensing section is covered with a restricting member that prevents the sample from penetrating around it so that the sample is dispensed only to the necessary areas.

[0008] Japanese Patent No. 6415827 Japanese Patent Application Laid-Open No. 2023-48923

[0009] Nipapan Ruecha, Orawon Chailapakul, Koji Suzuki and Daniel Chitterio “Fully Inkjet-Printed Paper-Based Potentiometric Ion-Sensing Devices” Analytical Chemistry August 29, 2017 Published, 89, pp. 10608-10616

[0010] However, with the above-described configuration, when a sufficiently large amount of sample is dispensed into the dispenser, the sample may spread over the restricting member, making it impossible to retain a sufficient amount of sample in the dispenser. Furthermore, when transporting the device after dispensing, the sample may flow out of the dispenser due to the impact of transportation. Therefore, it is necessary to retain a sufficient amount of sample in the dispenser so that measurement is not affected even when there is an impact from transportation.

[0011] An object of the present invention is to stably maintain the sample dispensed into the dispenser portion in the vicinity of the dispenser portion in the above analytical device.

[0012] The present invention provides an analytical device having a hydrophilic or porous flow path region surrounded by hydrophobic flow path walls provided inside or on a substrate, wherein the surface of the analytical device is provided with: a dispensing section into which the sample is dispensed; a region B adjacent to the periphery of the dispensing section, provided so as to surround the dispensing section and covered with a restricting member that is impermeable to the sample; and a region A formed adjacent to the side of region B that does not face the dispensing section, wherein a step is provided in the thickness direction of the analytical device at the boundary between region A and region B on the surface of the analytical device, and the step satisfies either of the following requirements (i) or (ii): (i) region A is lower than region B; (ii) region A is higher than region B, and region A is covered with a restricting member that is impermeable to the sample. The present invention also provides a testing method using the above analytical device, wherein the boundary between the region B and the region A is included in the range in which the sample spreads when the sample is dispensed.

[0013] As described above, according to the present invention, it is possible to provide a microchannel device that can protect the surface of the device while maintaining the stability of the dispensed sample in the dispenser, thereby enabling stable measurements.

[0014] FIG. 1 is a top view showing the configuration of an analytical device P1 according to Example 1. FIG. 2 is a simplified view showing the CC' cross section of the analytical device P1 shown in FIG. 1. FIG. 3 is a schematic view of a case where a sample is dispensed into the analytical device P1 according to Example 1. FIG. 4 is a schematic view of a case where a sample is dispensed into the analytical device P1 according to Example 1. FIG. 5 is a schematic view of a case where a sample is dispensed into the analytical device P1 according to Example 1. FIG. 6 is a top view showing the configuration of an analytical device P2 according to Example 2. FIG. 7 is a view showing the shapes of a restricting member 11, a restricting member cutout portion 12, and a restricting member cutout portion 13 in the vicinity of a dispensing section according to Examples 1 and 2. FIG. 8 is a view showing the shapes of a restricting member 11, a restricting member cutout portion 12, and a restricting member cutout portion 13 in the vicinity of a dispensing section according to Examples 1 and 2. FIG. 9 is a top view showing the configuration of an analytical device P3 according to Example 3. FIG. 10 is a schematic view of an analytical device P3 according to Example 3 from a cross-sectional direction. FIG. 11 is a schematic view of an analytical device P3 according to Example 3 from a cross-sectional direction. FIG. 1 is a schematic cross-sectional view of an analytical device P3 according to Example 3. FIG. 2 is a top view showing the configuration of another form of the analytical device P3 according to Example 3. FIG. 3 is a schematic cross-sectional view of another form of the configuration of the analytical device P3 according to Example 3. FIG. 4 is a schematic cross-sectional view of another form of the configuration of the analytical device P3 according to Example 3. FIG. 5 is a schematic cross-sectional view of another form of the configuration of the analytical device P3 according to Example 3.

[0015] The analytical device of the present invention is an analytical device having a hydrophilic or porous flow path region surrounded by hydrophobic flow path walls provided inside or on a substrate, and the surface of the analytical device is provided with: a dispensing section into which the sample is dispensed; a region B adjacent to the periphery of the dispensing section and provided so as to surround the dispensing section and covered with a restricting member that is impermeable to the sample; and a region A formed adjacent to the side of region B that is not facing the dispensing section, and the surface of the analytical device is characterized in that a step is provided in the thickness direction of the analytical device at the boundary between region A and region B, and the step satisfies either of the following requirements (i) or (ii): (i) region A is lower than region B; or (ii) region A is higher than region B, and region A is covered with a restricting member that is impermeable to the sample.

[0016] The testing method of the present invention is a testing method using the above-mentioned analytical device, characterized in that when the sample is dispensed, the boundary between the area A and the area B is included in the range in which the sample spreads.

[0017] In the present invention, the terms "dispensing section," "area B," and "boundary between area A and area B" refer to the area on the surface of the analytical device where the sample spreads.

[0018] The dispensing section, area B, and the boundary between area A and area B according to the present invention will be described in detail in Examples 1 to 3 below, but in cases where the amount of sample is large, the sample may wet and spread into area A (see Figure 9C).

[0019] 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. Furthermore, in the following drawings, components that are not necessary for explaining the embodiments are omitted. The analytical device according to the present invention has a hydrophilic or porous channel surrounded by hydrophobic channel walls provided inside or on a substrate.

[0020] Example 1 <Configuration of flow path> A schematic diagram of an analytical device P1 according to Example 1 will be described with reference to Figures 1 and 2. Figure 1 is a simplified top view of the analytical device P1. Figure 2 is a simplified view of the CC' cross section of the analytical device P1 shown in Figure 1.

[0021] The analytical device has a hydrophilic or porous flow channel region surrounded by hydrophobic flow channel walls provided inside or on a substrate. A flow channel pattern is formed in the porous substrate and has flow channel chamber 1, flow channel chamber 2, and flow channel 3. Flow channel 3 connects flow channel chamber 1 and flow channel chamber 2.

[0022] A reference electrode 7 is placed in the flow channel chamber 1. The top and side surfaces of the reference electrode 7 are covered with ionic crystals 10. The reference electrode 7 has a lead wire that extends continuously from inside the flow channel chamber 1 onto the flow channel wall 5 as a contact point during measurement.

[0023] A working electrode 8 is disposed in the flow channel chamber 2. An ion selective membrane 9 containing a component with ion selectivity covers the top and side surfaces of the working electrode 8. The working electrode 8 has a lead wire that continuously extends from the inside of the flow channel chamber 2 onto the flow channel wall 5. A dispensing unit 6 that dispenses the sample will be described later.

[0024] In Example 1, a hydrophobic resin was placed on a porous paper substrate having a thickness L1 of 0.1 mm and a porosity of 50%, and then thermally fixed to form a flow path pattern as a flow path wall 5 that was impermeable to samples.

[0025] In this example, a paper substrate was used as the porous substrate, but the porous substrate is not limited to paper. The porous substrate may be any material that generates capillary action in a liquid, and may have a porous structure such as open cells or nanofibers inside, or a mesh-like structure. Alternatively, resin, glass, an inorganic substrate, fabric, metal paper, etc. may be used.

[0026] In this embodiment, the flow path pattern is formed by applying a hydrophobic resin and then thermally fixing it, but the present invention is not limited to this. Any method may be used as long as the flow path pattern can be formed, such as by cutting a porous paper substrate to leave only the flow path shape, or by forming the flow path walls with a wax printer.

[0027] <Electrode formulation> The electrode formulation for Example 1 will be described with reference to Fig. 2. A reference electrode 7 made of Ag / AgCl was provided in the flow channel chamber 1. 1.8 mg of KCl ion crystals 10 were placed on the reference electrode 7.

[0028] On the other hand, a working electrode 8 made primarily of carbon is provided in the flow channel chamber 2. Note that instead of the carbon electrode, an electrode 8 made of a conductive polymer such as PEDOT:PSS (a dispersion of polyethylenedioxythiophene and polystyrene sulfonic acid) may be used. Also, a material such as Ag / AgCl, which has traditionally been used as the base of a reference electrode, may be used.

[0029] A Na ion-selective membrane 9 was formed to cover the working electrode 8. The ion-selective membrane 9 was made of the following materials: 3.0 wt % bis(12-crown-4) [Bis(12-crown-4)] as an ion-selective material, 0.5 wt % potassium tetrakis(4-chlorophenyl) borate [potassium tetrakis(4-chlorophenyl) borate] as an anion-removing agent, 64.0 wt % o-nitrophenyl octyl ether [o-nitrophenyl octyl ether], and 32.5 wt % polyvinyl chloride. In this example, the reference electrode 7, working electrode 8, and ion-selective membrane 9 were formed in the shapes, sizes, and materials described above, but the present invention is not limited to these.

[0030] The material of the ionic crystal 10 is not limited to KCl ionic crystals as long as it contains Cl ions. The mass of the ionic crystal 10 to be placed is not limited to this, but is within the range of mass that results in a saturated solution when the KCl ionic crystal is dissolved in pure water having a volume equivalent to the volume of the flow channel chamber 1.

[0031] Furthermore, when measuring the total amount of ions in a sample, the ion selective membrane 9 is not necessarily required.

[0032] <Shape of dispensing part and dispensing method> This will be explained using Figures 1 and 2. In this example, the dispensing part 6 shown in Figure 1 is the area on the exposed surface X of the ion selective membrane 9 shown in Figure 2. The exposed surface X is formed from a circle with a diameter of 4 mm centered at the center of the working electrode 8, and its area is approximately 12.6 mm ２ In addition, a restricting member 11 is provided to prevent the sample from coming into contact with areas other than the dispensing section, and a restricting member cutout portion 12, which is a cutout portion of the restricting member 11, is provided near the dispensing section 6.

[0033] Here, region A refers to the region on the surface of the analytical device cut out as the restriction member cutout portion 12 of the restriction member 11, and region B refers to the region on the restriction member 11 adjacent to the dispensing unit 6 and sandwiched between region A. In this case, region A is positioned opposite the dispensing unit 6 with region B sandwiched between them.

[0034] For example, a laminate film made of PET (polyethylene terephthalate) can be used as the regulating member 11. In this embodiment, a laminate film made of PET having a thickness of 50 μm is used.

[0035] The dispensing portion 6 has a width of φ5 mm from the center of the working electrode 8, and this portion is not covered by the restricting member 11. The restricting member cutout portion 12 is formed in a doughnut shape by cutting out the restricting member 11 with an inner diameter of φ7.5 mm and an outer diameter of φ9.5 mm.

[0036] Therefore, by dispensing the specimen onto the exposed surface X, it can be brought into sufficient contact with the ion selective membrane 9 over a wide contact area, and the specimen does not come into contact with the substrate in areas other than the dispensing area.

[0037] In order to dispense a sufficient amount of specimen onto the ion selective membrane 9, the specimen is dispensed with a contact area larger than the area of ​​the dispensing section 6. The specimen dispensed here is in an amount that touches the boundary between region A and region B, as shown in FIG.

[0038] <Analyte Penetration> The following describes analyte penetration. After the sample is dispensed onto the exposed surface X shown in Figure 2, ions contained in the sample and selected by the ion selective membrane 9 permeate toward the working electrode 8. In parallel with this permeation, the sample spreads over the exposed surface X, comes into contact with the porous substrate present around the ion selective membrane 9, permeates into the porous substrate, and, by capillary action, permeates through the flow channel 3 and the flow channel chamber 1 in that order. While the sample is permeating into the flow channel chamber 1, ions contained in the sample that come into contact with the exposed surface X are selected by the ion selective membrane 9, and the measurement potential of the working electrode 8, which is necessary for measuring the electrolyte concentration, becomes stable.

[0039] <Measurement of Analyte Concentration> Measurement of analyte concentration will now be described. When the analyte permeates the flow path 3 shown in Figure 2 by capillary action and reaches the KCl ion crystals 10 covering the reference electrode 7, the KCl ion crystals 10 dissolve in the analyte, and the Cl ion concentration in the solution in the flow path chamber 1 becomes saturated. If the measurement potential of the working electrode 8 is stable at this time, it becomes possible to measure the analyte concentration, and measurement of the analyte concentration ends after a predetermined measurement time has elapsed.

[0040] In this embodiment, since "ion selection by the ion selective membrane" and "permeation of the sample into the reference electrode" proceed in parallel, it is easy to achieve a stable state of the working electrode potential when the sample reaches the reference electrode 7.

[0041] In this example, the case where exposed surface X is the dispensing section 6 has been described. If the dispensed volume of the sample is equal to or greater than the volume that can reach flow channel chamber 1 via the upper part of exposed surface X, flow channel chamber 2, and flow channel 3, a sufficient amount of the sample can be brought into contact with ion selective membrane 9, and the sample concentration can be measured with good accuracy between the working electrode and the reference electrode.

[0042] Comparative Example 1 Comparative Example 1 will be presented to explain the effects of Example 1 in more detail. <Configuration of flow path, shape of dispensing portion> The shape of the flow path wall of the analytical device was the same as in Example 1. The configurations of the reference electrode, working electrode, ion selective membrane, etc. were also the same as in Example 1. However, the restricting member 11 was configured so that only the dispensing portion was exposed.

[0043] [Effects of Example 1] [Advantages of Example 1 over Comparative Example 1] The advantages of Example 1 over Comparative Example 1 will be described below. Figures 3A to 3D are schematic diagrams showing dispensing into the analytical device P1.

[0044] 3A shows the state immediately after dispensing onto the ion selective membrane 9 in Comparative Example 1. Here, the specimen S tends to remain in the dispensing portion due to surface tension, but when the specimen amount is large, the specimen S spreads onto the restricting member 11 due to the wettability relationship between the specimen and the restricting member 11, as shown in FIG.

[0045] 3C shows the case where the specimen is dispensed off-center from the ion selective membrane 9. In this case, if the restricting member 11 has better wettability than the ion selective membrane 9 in terms of the wettability relationship between the specimen, the ion selective membrane 9, and the restricting member 11, the specimen S will flow from the ion selective membrane 9 toward the restricting member 11.

[0046] Furthermore, even if the dispenser is in the state shown in Figure 3B, if the tip is transported after dispensing, the sample may move due to inertia caused by acceleration, or the sample may move due to inertia during deceleration or the impact of stopping, resulting in the state shown in Figure 3C.

[0047] 3D shows the configuration of Example 1. In the configuration of Example 1, by providing restricting member cutout portion 12 around the dispensing portion, during sample dispensing, the wet and spread dispensed sample is pinned at the boundary between area A and area B, i.e., the boundary between restricting member 11 and restricting member cutout portion 12. This pinning effect makes it possible to suppress the wet and spread of sample S, and to keep the sample in the dispensing portion.

[0048] In this embodiment, it was confirmed that the effect could be obtained if the width of region B was 1.0 mm to 1.5 mm, region A was 50 μm lower than region B (step 50 μm), and the width was 1.0 mm or more.

[0049] Therefore, in contrast to Comparative Example 1, in which no special structure is provided in the regulating member near the dispensing section, by providing a structure that pins the sample around the dispensing section as in Example 1, it becomes possible to retain the sample in any position, and by maintaining a sufficient amount of sample in the dispensing section even during measurement, stable measurement becomes possible.

[0050] [Example 2] An analysis device P2 in Example 2 will be described. In this example, only the differences from Example 1 will be described, the same members will be given the same reference numerals, and the description of similar parts will be omitted.

[0051] Fig. 4 is a top view showing a schematic configuration of the analytical device P2. Fig. 5A shows the shape of the restricting member 11 near the dispensing unit 6 as viewed from above for Example 1, and Fig. 5B shows the shape of the restricting member 11 as viewed from above for Example 2.

[0052] 5B , the restricting member cutouts 13 provided in the restricting member 11 are discontinuous, i.e., the restricting member 11 is not cut out in some localized areas, and the restricting member 11 covers the working electrode 8. In contrast to the restricting member cutouts 12 in Example 1, in Example 2, the restricting member 11 is left at equal intervals at three locations on the donut-shaped restricting member cutout 12, with the restricting member 11 remaining at an angle of 20°. In other words, the restricting member cutouts 13 are provided at three locations at equal intervals, with the restricting member 11 at an angle of 100°.

[0053] [Advantages of Example 2 Over Example 1] The following describes advantages of Example 2 over Example 1. In Example 1, as shown in Fig. 5A , the restricting member cutout portion 12 is continuous, so that a part of the working electrode 8 is exposed from the cutout portion.

[0054] However, if the sample comes into direct contact with the exposed working electrode 8 during dispensing due to, for example, unintentional scattering, the sample comes into direct contact with the electrode without passing through the ion selective membrane 9, which may result in failure to obtain the desired results. Therefore, it is desirable that the working electrode 8 is not exposed so that the sample does not come into contact with it. Therefore, in this embodiment, the restricting member cutout 12 in Example 1 is made discontinuous to form a restricting member cutout 13 so that the restricting member 11 remains on the working electrode 8.

[0055] Here, the specimen attempts to wet and advance on the restricting member 11 in the portions without cutouts, i.e., between adjacent restricting member cutout portions 13, but the wetting and spreading of the specimen is suppressed by the surface tension of the specimen and the pinning effect of the restricting member cutout portions 13. Here, if the distance between the restricting members 11 between adjacent restricting member cutout portions 13 is equal to or less than a certain width, the surface tension of the specimen can suppress the spreading of the droplet itself.

[0056] In the configuration of this embodiment, fetal bovine serum (hereinafter referred to as "FBS") is used as the specimen and PET is used as the restrictor member 11. Here, the wetting and spreading is determined by the wetting relationship between the ion selective membrane 9 and the FBS, and between the PET and, in this embodiment, the gap between adjacent restrictor member cutout portions 13 is at an angle of 20° with the dispensing portion as the center, but this angle may not be limited depending on the specimen and the material of the restrictor member 11.

[0057] Therefore, even if notches are not provided around the entire circumference of the restricting member 11 near the dispensing portion as in Example 1, the restricting member 11 is left to protect the portions that need to be covered to avoid contamination by unintended impurities, such as scattering of the sample during dispensing. By providing notches in other portions, it becomes possible to retain the sample in any position, and a sufficient amount of sample can be maintained in the dispensing portion even during measurement, enabling stable measurement.

[0058] [Example 3] An analytical device P3 in Example 3 will be described. In this example, only the differences from Example 1 will be described, the same components will be given the same reference numerals, and descriptions of similar parts will be omitted. Figure 6 is a top view showing a schematic configuration of the analytical device P3. Figures 7A to 7C are views showing cross sections of the dispensing unit 6 in the analytical device P3 shown in Figure 6.

[0059] In this embodiment, a step is provided on the restricting member 11 by attaching a restricting member 14 on the restricting member 11 near the outer periphery of the dispensing part 6 .

[0060] 7A, area A is the area on the restricting member 14, and area B is the area on the restricting member 11 sandwiched between the dispensing portion and area A. In this case, area A is positioned opposite the dispensing portion, with area B sandwiched between them.

[0061] As in Example 1, the dispensing part 6 has a width of φ5 mm from the center of the working electrode 8, and this portion is not covered by the restricting member 11. Furthermore, by providing a restricting member 14 having an opening with an inner diameter of φ7.5 mm from the center of the dispensing part 6 on the restricting member 11, a structure higher than the restricting member 11 (a step in the thickness direction of the analytical device) is formed, as shown in Fig. 7A . Here, the restricting member 14 is made of a PET laminate film with a thickness of 50 µm, the same as that of the restricting member 11.

[0062] [Effects of Example 3] When a sufficient amount of sample is dispensed into the dispensing section 6, the sample spreads from the dispensing section to wet the area B. However, as shown in FIG. 7B, the presence of the restricting member 14 allows the sample S to be pinned by the edge of the inner periphery of the restricting member 14, thereby making it possible to retain the sample in the dispensing section.

[0063] 7C, by stacking a restricting member 15 with a hole of an even larger outer diameter on the restricting member 14 of FIG. 7A (the step is formed in a staircase shape by region B and region A which is one or more steps higher than region B), even if the amount of sample that arrives exceeds the pinning effect at the edge of FIG. 7A and the sample spreads over the edge and wets the restricting member 14, the sample will be pinned at the edge of the inner periphery of the restricting member 15. Increasing the number of points at which the sample can be pinned in this way makes it possible to firmly hold the sample in the dispensing section.

[0064] 8 and 9A, a structure higher than the restricting member 11 may be formed by providing the restricting member 14 on the restricting member 11 with an inner diameter of 7.5 mm and an outer diameter of 9.5 mm from the center of the dispensing unit 6. In this structure, as shown in FIG. 9B, the sample S is first pinned at the inner edge of the restricting member 14 as described above. If an amount of sample dispensed exceeds this pinning effect, the sample S spreads over the restricting member 14, which is region A, as shown in FIG. 9C. When the sample reaches the outer edge of the restricting member 14, a pinning effect similar to that in Example 1 is exerted. Therefore, in this example, the sample can be pinned at two points: the inner edge and the outer edge of the restricting member 14.

[0065] Although the flow channel of the present invention has been described as an example of a flow channel surrounded by a flow channel wall formed of a hydrophobic resin disposed inside a porous substrate, it may also be a flow channel using a hydrophobic sheet such as PET as the substrate and having its surface rendered hydrophilic by plasma treatment, corona discharge treatment, or surface coating with a hydrophilic polymer. The hydrophilic polymer may be, for example, polyethylene glycol (PEG), EVAL (EVOH), poval (PVOH), or a polymer containing a phosphorylcholine group. A coating layer formed by applying and drying a liquid blend consisting of hydrophilic inorganic fine particles, polymer fine particles dispersed in an aqueous medium, or a reactive organic fluorine compound may also be used. The hydrophilicity of the flow channel allows the analyte to migrate. Furthermore, by providing a regulating member such as that of the present invention on the flow channel so as to form a gap between the flow channel and the regulating member, capillary action due to the gap between the flow channel and the regulating member is also added, thereby accelerating the analyte migration. Alternatively, a hydrophobic sheet may be used as the substrate and a porous member flow channel may be provided on the surface of the sheet. The flow channel of the present invention may be any hydrophilic or porous flow channel surrounded by a hydrophobic flow channel wall disposed inside or on the substrate.

[0066] <Summary> As described above, by providing a notch in the regulating member 11 or by stacking additional regulating members to create a height difference, it is possible to pin the sample and retain the sample in the dispensing section even if it is subjected to impacts during transportation, etc., thereby making it possible to provide a microchannel device that can perform stable measurements.

[0067] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention.

[0068] This application claims priority based on Japanese Patent Application No. 2024-062886, filed April 9, 2024, the entire contents of which are incorporated herein by reference.

[0069] DESCRIPTION OF SYMBOLS 1: Flow path chamber (flow path chamber 1) including reference electrode 7 2: Flow path chamber (flow path chamber 2) including working electrode 8 3: Flow path connecting flow path chamber 1 and flow path chamber 2 5: Flow path wall 6: Dispensing section 7: Reference electrode 8: Working electrode 9: Ion selective membrane 10: Ion crystal including Cl ions 11: Restriction member 12: Restriction member cutout portion 13: Restriction member cutout portion 14: Restriction member 15: Restriction member S: Specimen X: Exposed surface of ion selective membrane 9

Claims

1. An analytical device having a hydrophilic or porous flow path region surrounded by hydrophobic flow path walls provided inside or on a substrate, wherein the surface of the analytical device is provided with: a dispensing section into which the sample is dispensed; a region B adjacent to the periphery of the dispensing section and provided so as to surround the dispensing section and covered with a restricting member that is impermeable to the sample; and a region A formed adjacent to the side of region B that is not facing the dispensing section, wherein a step is provided in the thickness direction of the analytical device at the boundary between region A and region B on the surface of the analytical device, and the step satisfies either of the following requirements (i) or (ii): (i) region A is lower than region B; (ii) region A is higher than region B, and region A is covered with a restricting member that is impermeable to the sample.

2. The analytical device according to claim 1, wherein the step satisfies the requirement (i), and the region A is a region where the regulating member is not present and is formed in a donut shape.

3. An analytical device according to claim 1, wherein the step satisfies the requirement (i) and the region A is formed by providing discontinuous regions where the regulating member is not present.

4. The analytical device according to claim 1, wherein the step satisfies the requirement (ii) and the region A is formed in a donut shape.

5. A method for testing a specimen using the analytical device according to any one of claims 1 to 4, characterized in that the boundary between said area A and said area B is included in the range in which the specimen spreads when dispensed.

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