Inspection chip and manufacturing method thereof

Abstract

The invention provides an inspection chip in which uneven color development is significantly suppressed. The inspection chip is characterized in that the inspection chip is in a sheet shape and is provided with a first layer on the front surface side and a second layer on the back surface side, the first layer and the second layer are adjacent to each other, either the first layer or the second layer has a liquid receiving part A, the first layer has at least a detection confirmation part B, and the second layer has at least a detection confirmation part C; and a second layer having at least a liquid flow section D adjacent to the detection confirmation section B and a liquid flow path E connected to the liquid flow section D. The first layer is formed on one surface of one sheet-like material, and the second layer is formed on the other surface of the sheet-like material. The first layer has the liquid receiving section (A) separated from the detection confirmation section (B), and the second layer has a liquid circulation section (C) adjacent to the liquid receiving section (A). The liquid to be detected flows through the liquid receiving part A, the liquid flowing part C, the liquid flowing path E and the liquid flowing part D in sequence through a capillary phenomenon and then flows to the detection confirmation part B. The liquid to be detected flows through the liquid receiving part A, the liquid flowing part C, the liquid flowing path E and the liquid flowing part D in sequence.

Description

[0001] This application is a divisional application of the original application, with an application date of April 1, 2021, application number 202180029553.8, and invention name “Inspection chip and its manufacturing method”. Technical Field

[0002] The present invention relates to an inspection chip and a method for manufacturing the same. Background Art

[0003] The concept of being able to perform diagnosis right next to the patient (on-site diagnosis) is becoming increasingly important in clinical settings. With this in mind, a new test chip has been developed that enables practical analysis by incorporating microscale flow channels and reaction sites onto a sheet-like substrate.

[0004] One example of such a test chip has a mechanism whereby, when a test fluid containing a target substance, such as an antigen, is introduced, the test fluid flows through a flow path, and a pre-introduced labeling medium, such as an antibody, reacts with the target substance, resulting in a color development (color development), thereby confirming the presence of the target substance. Pregnancy test drugs are a typical example of this mechanism.

[0005] As a test chip such as the above, a microfluidic device has been reported (Non-Patent Document 1) that uses paper as a substrate and forms flow paths and reaction points on the paper using a wax printer or inkjet printer. This device is also called "μ-PADs (microfluidic paper-based analytical devices)" and has many advantages, such as (1) low cost, (2) no pump, (3) no need for large-scale equipment, and (4) easy disposal. In addition, research on the improvement of such μ-PADs is progressing worldwide.

[0006] For example, Patent Document 1 discloses that an inspection chip can be manufactured simply and at low cost by printing the outer edges of the above-mentioned flow channels and reaction sites on paper using ultraviolet curable ink and curing the ink by irradiating ultraviolet rays.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2012 / 160857

[0010] Non-patent literature

[0011] Non-patent document 1: Whiteside et al., Analytical Chemistry, Vol. 82, No. 1, January 1, 2010 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] However, conventional inspection chips, including the technology of Patent Document 1, are prone to uneven color development, which can lead to deviations in inspection results (insufficient reproducibility). For example, because color development occurs near the ends of the detection area, it is difficult to visually observe. This problem can adversely affect the diagnosis of major diseases, etc. Therefore, there is room for improvement in conventional inspection chips in terms of suppressing uneven color development.

[0014] Furthermore, for inspection chips such as the aforementioned μ-PADs, in addition to confirming the presence of the target substance, it is also desirable to quantify its presence. Regarding this, if the aforementioned uneven color development (color rendering) can be suppressed, quantification can be achieved by determining the area of ​​the portion of the inspection chip where color is displayed and applying pixel analysis technology. From this perspective, suppressing uneven color development is also desirable.

[0015] The present invention aims to solve the aforementioned problems and achieve the following objectives. Specifically, the present invention aims to provide an inspection chip with significantly suppressed color unevenness, wherein the inspection chip is used to react a target substance contained in an inspection fluid with a pre-installed labeling medium, and to confirm the presence of the target substance through the color development caused by the reaction. Furthermore, the present invention aims to provide a method for manufacturing the inspection chip, which enables simple, high-precision, and low-cost manufacturing of the inspection chip.

[0016] Means for solving problems

[0017] To solve the above-mentioned problems, the present inventors first found that the problem in conventional inspection chips, in which color development occurs near the end of the detection region, is caused by the momentum of the liquid flow reaching the detection region.

[0018] Furthermore, the present inventors have conducted intensive research and have discovered that by optimizing the liquid flow path so that the liquid can reach the detection area from the thickness direction of the sheet, color development can be produced near the center of the detection area, thereby completing the present invention.

[0019] Means for achieving the above-mentioned object are as follows.

[0020] <1> An inspection chip, characterized in that it is a sheet-shaped inspection chip,

[0021] It has a first layer on the front side and a second layer on the back side,

[0022] The first layer and the second layer are adjacent,

[0023] Either the first layer or the second layer has a liquid receiving portion A,

[0024] The first layer at least has a detection confirmation part B,

[0025] The second layer has at least a liquid flow portion D adjacent to the detection confirmation portion B and a liquid flow path E connected to the liquid flow portion D.

[0026] In the case where the first layer has a liquid receiving portion A, the liquid receiving portion A is separated from the detection confirmation portion B.

[0027] The structure is such that when the test liquid is dropped into the liquid receiving part A, the test liquid flows sequentially through the liquid receiving part A, the liquid flow path E and the liquid flow part D to the detection confirmation part B by capillary phenomenon.

[0028] The first layer is formed on one surface of a sheet-like material, and the second layer is formed on the other surface of the sheet-like material.

[0029] <2> An inspection chip, characterized in that it is a sheet-shaped inspection chip,

[0030] It has a first layer on the front side and a second layer on the back side,

[0031] The first layer and the second layer are adjacent,

[0032] Either the first layer or the second layer has a liquid receiving portion A,

[0033] The first layer at least has a detection confirmation part B,

[0034] The second layer has at least a liquid flow portion D adjacent to the detection confirmation portion B and a liquid flow path E connected to the liquid flow portion D.

[0035] In the case where the first layer has a liquid receiving portion A, the liquid receiving portion A is separated from the detection confirmation portion B.

[0036] The structure is such that when the test liquid is dropped into the liquid receiving part A, the test liquid flows sequentially through the liquid receiving part A, the liquid flow path E and the liquid flow part D to the detection confirmation part B by capillary phenomenon.

[0037] The liquid flow portion D is an annular structure having a liquid non-flow portion D' formed inside.

[0038] <3> An inspection chip, characterized in that it is a sheet-shaped inspection chip,

[0039] It has a first layer on the front side and a second layer on the back side,

[0040] The first layer and the second layer are adjacent,

[0041] Either the first layer or the second layer has a liquid receiving portion A,

[0042] The first layer at least has a detection confirmation part B,

[0043] The second layer has at least a liquid flow portion D adjacent to the detection confirmation portion B and a liquid flow path E connected to the liquid flow portion D.

[0044] In the case where the first layer has a liquid receiving portion A, the liquid receiving portion A is separated from the detection confirmation portion B.

[0045] The structure is such that when the test liquid is dropped into the liquid receiving part A, the test liquid flows sequentially through the liquid receiving part A, the liquid flow path E and the liquid flow part D to the detection confirmation part B by capillary phenomenon.

[0046] The second layer has a plurality of liquid flow paths E.

[0047] <4> according to <3> In the inspection chip, at least two of the liquid flow paths E are connected to the liquid flow portion D in a manner that they are opposed to each other.

[0048] <5> according to <3> or <4> In the inspection chip, at least two of the liquid flow paths E have substantially the same shape.

[0049] <6> according to <1> ~ <5> The inspection chip according to any one of the preceding claims, wherein:

[0050] The first layer has the liquid receiving portion A separated from the detection confirmation portion B,

[0051] The second layer has a liquid passing portion C adjacent to the liquid receiving portion A.

[0052] When the test liquid is dropped into the liquid receiving portion A, the test liquid flows sequentially through the liquid receiving portion A, the liquid flowing portion C, the liquid flow path E, and the liquid flowing portion D to the detection confirmation portion B by capillary action.

[0053] <7> according to <1> ~ <5> any one of the inspection chips,

[0054] The first layer has the liquid receiving portion A separated from the detection confirmation portion B, and further has a liquid flow path F connected to the liquid receiving portion A.

[0055] When the test liquid is dropped into the liquid receiving part A, the test liquid flows sequentially through the liquid receiving part A, the liquid flow path F, the liquid flow path E, and the liquid flow part D to the detection confirmation part B by capillary action.

[0056] <8> according to <1> ~ <5> The inspection chip described in any one of the preceding claims, wherein the second layer has the liquid receiving portion A.

[0057] <9> according to <1> ~ <8> The inspection chip according to any one of the preceding claims, wherein:

[0058] The liquid receiving portion A, any of the liquid circulating portions C, any of the liquid flow paths F, the liquid flow paths E, the liquid circulating portion D, and the detection confirmation portion B are formed of a material M that allows the liquid to flow by capillary action.

[0059] The portion other than the material M is formed of a material M′ in which the material M is impregnated with a hydrophobic material and in which no test liquid flows.

[0060] <10> according to <9> The inspection chip, wherein the raw material M is filter paper.

[0061] <11> according to <9> or <10> In the inspection chip, the impregnation rate of the hydrophobic material in the raw material M′ into the raw material M is 14% or more and 32% or less.

[0062] <12> according to <1> ~ <11> The inspection chip according to any one of the preceding claims, wherein a ratio of the thickness of the second layer to the thickness of the first layer (thickness of the second layer / thickness of the first layer) is greater than or equal to 0.56 and less than or equal to 2.2.

[0063] <13> according to <1> ~ <12> The inspection chip according to any one of the preceding claims, wherein a color development reaction caused by the detection target substance occurs in the detection confirmation portion B.

[0064] <14> A method for manufacturing an inspection chip, characterized in that <1> ~ <13> The method for manufacturing a test chip according to any one of the above-mentioned steps comprises:

[0065] a film forming step of forming a first hydrophobic film on the first substrate and a second hydrophobic film on the second substrate using a hydrophobic material;

[0066] a first printing step of using the first hydrophobic film on the first substrate to print on the first sacrificial substrate in a manner that becomes an inverse design of the first layer of the inspection chip;

[0067] a second printing step of using the second hydrophobic film on the second substrate to print on a second sacrificial substrate in a manner that becomes an inverse design of the second layer of the inspection chip;

[0068] a first transfer step of transferring the first hydrophobic film after the first printing step to one surface of a sheet-like material and impregnating the sheet-like material with the first hydrophobic film; and

[0069] In the second transfer step, the second hydrophobic film after the second printing step is transferred to the other surface of the one sheet-like material, and the second hydrophobic film is impregnated into the sheet-like material.

[0070] <15> according to <14> In the method for manufacturing the inspection chip, a ratio of the thickness of the second hydrophobic film to the thickness of the first hydrophobic film (thickness of the second hydrophobic film / thickness of the first hydrophobic film) is greater than or equal to 0.56 and less than or equal to 2.2.

[0071] Effects of the Invention

[0072] According to the present invention, a test chip with significantly suppressed color unevenness can be provided. This test chip is used to react a target substance contained in a test fluid with a pre-installed labeling medium, and to confirm the presence of the target substance through the color development caused by this reaction. Furthermore, the present invention can provide a method for manufacturing the test chip, enabling simple, high-precision, and low-cost production of the test chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] [ Figure 1A ] is a schematic three-dimensional diagram of an inspection chip of an example of the present invention.

[0074] [ Figure 1B ]yes Figure 1A A schematic three-dimensional diagram of the inspection chip.

[0075] [ Figure 2 ]yes Figure 1A Schematic plan view of the front and back of the inspection chip.

[0076] [ Figure 3 ]yes Figure 1A Schematic cross-sectional view of the inspection chip.

[0077] [ Figure 4 ] is a diagram schematically decomposing an inspection chip according to one embodiment of the present invention.

[0078] [ Figure 5 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0079] [ Figure 6 ]yes Figure 5 Schematic cross-sectional view of the inspection chip.

[0080] [ Figure 7 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0081] [ Figure 8 ]yes Figure 7 Schematic cross-sectional view of the inspection chip.

[0082] [ Figure 9 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0083] [ Figure 10 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0084] [ Figure 11 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0085] [ Figure 12 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0086] [ Figure 13 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0087] [ Figure 14 ] is a schematic plan view of the front and back surfaces of an inspection chip according to an example of the present invention.

[0088] [ Figure 15 ] is a schematic cross-sectional view of an inspection chip according to an example of the present invention.

[0089] [ Figure 16 ] is a schematic plan view of the surface and back of an inspection chip of a comparative example. DETAILED DESCRIPTION

[0090] Hereinafter, the present invention will be described in detail based on embodiments.

[0091] (Check chip)

[0092] The basic feature of the inspection chip of the present invention is that it is a sheet-shaped inspection chip.

[0093] It has a first layer on the front side and a second layer on the back side,

[0094] The first layer and the second layer are adjacent,

[0095] Either the first layer or the second layer has a liquid receiving portion A,

[0096] The first layer at least has a detection confirmation part B,

[0097] The second layer has at least a liquid flow portion D adjacent to the detection confirmation portion B and a liquid flow path E connected to the liquid flow portion D.

[0098] In the case where the first layer has a liquid receiving portion A, the liquid receiving portion A is separated from the detection confirmation portion B.

[0099] When the test liquid is dropped into the liquid receiving portion A, the test liquid flows sequentially through the liquid receiving portion A, the liquid flow path E, and the liquid flow portion D to the detection confirmation portion B by capillary action.

[0100] In addition to the above basic features, the inspection chip according to one embodiment of the present invention is further characterized in that the liquid-passing portion D is an annular structure having a liquid-impeded portion D' formed inside.

[0101] Furthermore, in addition to the above basic features, the inspection chip according to another embodiment of the present invention is further characterized in that the second layer has a plurality of the liquid flow paths E. Details of this feature will be described later.

[0102] In addition, in addition to the above basic features, another embodiment of the inspection chip of the present invention is characterized in that the first layer is formed on one surface of a sheet material, and the second layer is formed on the other surface of the sheet material. Details of this feature will be described later.

[0103] According to these inspection chips, uneven color development can be significantly suppressed.

[0104] In the inspection chip of the present invention, the liquid receiving portion A is where the test liquid is dripped. Furthermore, in the inspection chip of the present invention, the detection confirmation portion B is where the presence of a target substance, such as an antigen, in the test liquid dripped into the liquid receiving portion A is confirmed based on the presence or absence of color development. Therefore, the inspection chip 1 of the present invention can include a medium that reacts with the test substance and / or a labeled medium that induces a color reaction with the test substance at appropriate locations. Furthermore, the inspection chip 1 of the present invention preferably generates a color reaction with the test substance in the detection confirmation portion B.

[0105] As modes of the above-mentioned basic characteristics commonly possessed by the inspection chip of the present invention, more specifically, there can be cited a mode in which the liquid receiving part A is arranged on the first layer and the second layer has a liquid flow part C (first mode), a mode in which the liquid receiving part A is arranged on the first layer and the first layer also has a liquid flow path F connected to the above-mentioned liquid receiving part A (second embodiment), and a mode in which the liquid receiving part A is arranged on the second layer (third mode).

[0106] <Basic Features of the First Method>

[0107] Figure 1A and Figure 1B Each of them is a schematic perspective view of a first embodiment of the inspection chip 1. The inspection chip 1 comprises a first layer 10 on the front side, that is, the side where the inspection result is visually confirmed by the inspector during use, and a second layer 20 on the back side. Figure 1A This is a perspective view with the surface of the inspection chip 1 facing upward. Figure 1B This is a perspective view with the back side of the inspection chip 1 facing upward. Figure 1A and Figure 1B As shown, the inspection chip 1 is in the form of a sheet. In addition, the first layer 10 and the second layer 20 in the inspection chip 1 are adjacent to each other without any layer interposed therebetween. In addition, the shape of the inspection chip 1 when viewed from above is not particularly limited and can be appropriately selected according to the purpose. For example, Figure 1A as well as Figure 1B The shape shown is rectangular, but it can also be circular, elliptical, etc.

[0108] Figure 2 This is a schematic plan view of the front and back surfaces of the inspection chip 1. Figure 1A and Figure 1B The inspection chip 1 shown corresponds to Figure 2 As shown, the inspection chip 1 includes a first layer 10 disposed on the surface side and provided with a liquid receiving portion A and a detection confirmation portion B. The liquid receiving portion A and the detection confirmation portion B are separated in the first layer 10 of the inspection chip 1 .

[0109] Furthermore, a liquid-impermeable portion X is provided on the first layer 10 of the inspection chip 1 as a portion other than the liquid receiving portion A and the detection confirmation portion B. The liquid receiving portion A and the detection confirmation portion B are formed, for example, from a material M that allows the flow of the test liquid due to capillary action. Furthermore, the liquid-impermeable portion X is formed, for example, from a material M' that does not allow the flow of the test liquid.

[0110] In addition, if Figure 2As shown, the inspection chip 1 is provided with a liquid circulation portion C, a liquid circulation portion D, and a liquid flow path E in the second layer 20 disposed on the back side. The liquid flow path E is connected to the liquid circulation portion D and is also connected to the liquid circulation portion C. Furthermore, in the second layer 20 of the inspection chip 1, a liquid non-circulating portion Y is provided as a portion other than the liquid circulation portion C, the liquid flow path E, and the liquid circulation portion D. Furthermore, the liquid circulation portion C, the liquid flow path E, and the liquid circulation portion D are formed from a material M that exhibits the circulation of the test liquid by capillary action, similar to the aforementioned liquid receiving portion A and detection confirmation portion B. Furthermore, the liquid non-circulating portion Y is formed from a material M' that does not exhibit the circulation of the test liquid, similar to the aforementioned liquid non-circulating portion X.

[0111] exist Figure 3 shown in the Figure 2 A schematic cross-sectional view of the inspection chip 1 when cut along the a-a' line. Figure 3 As shown, in the inspection chip 1 having the first configuration, the liquid receiving portion A of the first layer 10 is adjacent to the liquid passing portion C of the second layer 20, and the detection confirmation portion B of the first layer 10 is adjacent to the liquid passing portion D of the second layer 20. That is, in the inspection chip 1 having the first configuration, the liquid receiving portion A, the liquid passing portion C, the liquid flow path E, the liquid passing portion D, and the detection confirmation portion B are sequentially adjacent or connected. In other words, the inspection chip 1 having the first configuration is configured such that when a test liquid is dropped into the liquid receiving portion A, the test liquid flows sequentially through the liquid receiving portion A, the liquid passing portion C, the liquid flow path E, the liquid passing portion D, and finally to the detection confirmation portion B by capillary action.

[0112] In this regard, conventional inspection chips simply connect the liquid receiving portion and the detection confirmation portion (detection area) via a flow path on the substrate. Therefore, when the test liquid is dripped onto the liquid receiving portion, the momentum of the liquid flow advancing along the surface of the substrate and reaching the detection area causes uneven color development, resulting in uneven color development near the ends of the detection area (particularly near the ends away from the liquid receiving portion). On the other hand, in the inspection chip 1 described above, due to the aforementioned structure, the test liquid dripped onto the liquid receiving portion A ultimately reaches the detection confirmation portion B in the thickness direction of the inspection chip 1 (from the liquid flow portion D toward the detection confirmation portion B). Therefore, in the inspection chip 1 having the first embodiment, the color development portion can be kept near the center of the detection confirmation portion B, thereby significantly suppressing uneven color development.

[0113] As described above, the liquid receiving portion A and detection confirmation portion B in the first layer 10, and the liquid passing portion C, liquid passing portion D, and liquid flow path E in the second layer 20 are formed from, for example, a material M that allows the flow of the test liquid by capillary action. On the other hand, the liquid non-passing portion X in the first layer 10 and the liquid non-passing portion Y in the second layer 20 are formed from, for example, a material M' that is formed by impregnating the material M with a hydrophobic material and does not allow the flow of the test liquid.

[0114] Will be schematically decomposed Figure 1A and Figure 1B The diagram of the inspection chip 1 is shown in Figure 4 .like Figure 4 As shown on the left side of FIG, the inspection chip 1 schematically comprises: the above-mentioned raw material M, a predetermined first layer 10' having a design of the first layer 10 and composed of a hydrophobic material 50, and a predetermined second layer 20' having a design of the second layer 20 and composed of a hydrophobic material 50. In addition, as Figure 4 As shown on the left side of FIG, the inspection chip 1 has a structure in which a predetermined first layer 10' and a predetermined second layer 20' are impregnated with the raw material M from both sides. Figure 4 As shown on the right side of FIG, from the viewpoint of raw materials, the inspection chip 1 includes, for example, a raw material M and a raw material M′ in which the raw material M is impregnated with a hydrophobic material 50 .

[0115] The raw material M is not particularly limited as long as it can produce capillary action. Examples include filter paper, nonwoven fabrics, nitrocellulose, and polypropylene. Filter paper is preferred for easier and more cost-effective production of the inspection chip. The thickness and weight per unit area (density) of the raw material M can be appropriately selected based on factors such as the viscosity of the fluid being inspected.

[0116] The hydrophobic material is not particularly limited as long as it can be impregnated into the raw material M and inhibit capillary action in the raw material M. Examples thereof include wax and compositions containing the same. Furthermore, from the perspective of ease of production, the melting point of the hydrophobic material is preferably 90° C. or lower.

[0117] In the above-mentioned inspection chip, the material M' of the liquid-impermeable portion X on the front side is preferably colored to facilitate visual confirmation of the liquid receiving portion A and the detection confirmation portion B on the front side by the inspector. Meanwhile, the material M' of the liquid-impermeable portion Y on the back side of the inspection chip may be colored, or may be white, transparent, or uncolored.

[0118] Coloring of the raw material M' can be achieved, for example, by impregnating the raw material M with a colorant in addition to the hydrophobic material. The colorant is preferably hydrophobic, and examples thereof include pigments such as carbon black (black pigment). Furthermore, the colorant is preferably selected so as not to adversely affect the reagents used in the test chip.

[0119] The shape of the liquid receiving part A when viewed from above is not particularly limited and can be appropriately selected according to the purpose. For example, Figure 2 The shape shown is circular, but it can also be oval, rectangular, etc.

[0120] The shape of the detection confirmation part B when viewed from above is not particularly limited and can be appropriately selected according to the purpose. Figure 2 The shape shown is circular, but it can also be oval, rectangular, etc.

[0121] The shape of the liquid flow portion C when viewed in plan is not particularly limited and can be appropriately selected depending on the purpose, but is preferably the same shape as the liquid receiving portion A. Furthermore, the liquid flow portion C preferably has a shape substantially identical to that of the liquid receiving portion A when viewed in plan on the inspection chip.

[0122] The shape of the liquid flow section D when viewed in plan is not particularly limited and can be appropriately selected depending on the purpose, but is preferably the same shape as the detection confirmation section B. Furthermore, the liquid flow section D preferably has a shape substantially identical to that of the detection confirmation section B when viewed in plan on the inspection chip.

[0123] The thickness of the inspection chip of the present invention is not particularly limited, and can be, for example, 100 to 300 μm.

[0124] Although not shown, the inspection chip of the present invention may include a plurality of combinations of the detection confirmation portion B, the liquid circulation portion D, and the liquid flow path E. In this case, the presence or absence of a plurality of detection target substances can be simultaneously confirmed in a single inspection.

[0125] <Second form of basic characteristics>

[0126] Figure 5 1 is a schematic plan view of the front and back surfaces of the inspection chip 1 having the second embodiment. Figure 5 As shown, the inspection chip 1 is provided with a liquid receiving portion A and a detection confirmation portion B in the first layer 10 disposed on the surface side. These liquid receiving portion A and detection confirmation portion B are separated in the first layer 10 of the inspection chip 1. In addition, the inspection chip 1 has a liquid flow path F connected to the liquid receiving portion A in the first layer 10 disposed on the surface side.

[0127] Furthermore, a liquid-impermeable portion X is provided in the first layer 10 of the inspection chip 1 as a portion other than the liquid receiving portion A, the detection confirmation portion B, and the liquid flow path F. The liquid receiving portion A, the detection confirmation portion B, and the liquid flow path F are formed, for example, from a material M that allows the flow of the test liquid due to capillary action. Furthermore, the liquid-impermeable portion X is formed, for example, from a material M' that does not allow the flow of the test liquid.

[0128] In addition, if Figure 5 As shown, the inspection chip 1 is provided with a liquid flow section D and a liquid flow path E in the second layer 20 disposed on the back side. The liquid flow path E is connected to the liquid flow section D. Furthermore, in the second layer 20 of the inspection chip 1, a liquid non-flowing section Y is provided as a portion other than the liquid flow path E and the liquid flow section D. Furthermore, the liquid flow path E and the liquid flow section D are formed from a material M that allows the flow of the test liquid by capillary action, similar to the liquid receiving section A, the detection confirmation section B, and the liquid flow path F described above. Furthermore, the liquid non-flowing section Y is formed from a material M' that does not allow the flow of the test liquid, similar to the liquid non-flowing section X described above.

[0129] exist Figure 6 shown in the Figure 5 A schematic cross-sectional view of the inspection chip 1 when cut along line bb'. Figure 6 As shown, in the inspection chip 1 having the second aspect, the detection confirmation section B of the first layer 10 is adjacent to the liquid flow section D of the second layer 20, and the liquid flow path F of the first layer 10 is connected to the liquid flow path E of the second layer 20. That is, in the inspection chip 1 having the second aspect, the liquid receiving section A, the liquid flow path F, the liquid flow path E, the liquid flow section D, and the detection confirmation section B are sequentially adjacent or connected. In other words, the inspection chip 1 having the second aspect is configured such that when a test liquid is dropped into the liquid receiving section A, the test liquid flows sequentially through the liquid receiving section A, the liquid flow path F, the liquid flow path E, and the liquid flow section D by capillary action, ultimately reaching the detection confirmation section B. Therefore, in the inspection chip 1 having the second aspect, similar to the first aspect, the test liquid dropped into the liquid receiving section A ultimately reaches the detection confirmation section B along the thickness direction of the inspection chip 1 (from the liquid flow section D toward the detection confirmation section B). Therefore, also in the inspection chip 1 having the second aspect, the colored portion can be kept near the center of the detection confirmation portion B, and thus uneven color development can be significantly suppressed.

[0130] As described above, the liquid receiving portion A, detection confirmation portion B, and liquid flow path F in the first layer 10, and the liquid passing portion D and liquid flow path E in the second layer 20 are formed, for example, from a material M that allows the flow of the test liquid by capillary action. On the other hand, the liquid non-flowing portion X in the first layer 10 and the liquid non-flowing portion Y in the second layer 20 are formed from a material M' that does not allow the flow of the test liquid, for example, by impregnating the material M with a hydrophobic material.

[0131] In the above-mentioned inspection chip, the material M' of the liquid-impermeable portion X on the front side is preferably colored to facilitate visual confirmation of the liquid receiving portion A and the detection confirmation portion B on the front side by the inspector. Meanwhile, the material M' of the liquid-impermeable portion Y on the back side of the inspection chip may be colored, or may be white, transparent, or uncolored.

[0132] Except for the above, description of matters common to the first embodiment will be omitted.

[0133] <Third Form of Basic Characteristics>

[0134] Figure 7 1 is a schematic plan view of the front and back surfaces of the inspection chip 1 having the third form. Figure 7 As shown, the inspection chip 1 is provided with a detection confirmation portion B on the first layer 10 arranged on the surface side, and is not provided with a liquid receiving portion A.

[0135] Furthermore, a liquid-impermeable portion X is provided in the first layer 10 of the inspection chip 1 as a portion other than the detection confirmation portion B. The detection confirmation portion B is formed, for example, from a material M that allows the flow of the test liquid due to capillary action. Furthermore, the liquid-impermeable portion X is formed, for example, from a material M' that does not allow the flow of the test liquid.

[0136] In addition, if Figure 7 As shown, the inspection chip 1 is provided with a liquid receiving portion A, a liquid flowing portion D, and a liquid flow path E on the second layer 20 disposed on the back side. The liquid flow path E is connected to the liquid flowing portion D and is also connected to the liquid receiving portion A. Furthermore, a liquid non-flowing portion Y is provided in the second layer 20 of the inspection chip 1 as a portion other than the liquid receiving portion A, the liquid flow path E, and the liquid flowing portion D. Furthermore, the liquid receiving portion A, the liquid flow path E, and the liquid flowing portion D are formed from a material M that allows the flow of the test liquid by capillary action, similar to the detection confirmation portion B described above. Furthermore, the liquid non-flowing portion Y is formed from a material M' that does not allow the flow of the test liquid, similar to the liquid non-flowing portion X described above.

[0137] exist Figure 8 shown in the Figure 7A schematic cross-sectional view of the inspection chip 1 when cut along the c-c' line. Figure 8 As shown, in the inspection chip 1 having the third embodiment, the detection confirmation section B of the first layer 10 is adjacent to the liquid flow section D of the second layer 20. That is, in the inspection chip 1 having the third embodiment, the liquid receiving section A, the liquid flow path E, the liquid flow section D, and the detection confirmation section B are sequentially adjacent or connected. In other words, the inspection chip 1 having the third embodiment is configured such that when a test liquid is dripped into the liquid receiving section A, the test liquid flows sequentially through the liquid receiving section A, the liquid flow path E, and the liquid flow section D by capillary action, ultimately reaching the detection confirmation section B. Therefore, in the inspection chip 1 having the third embodiment, similar to the first embodiment, the test liquid dripped into the liquid receiving section A ultimately reaches the detection confirmation section B in the thickness direction of the inspection chip 1 (from the liquid flow section D toward the detection confirmation section B). Consequently, in the inspection chip 1 having the third embodiment, the coloring area can be kept near the center of the detection confirmation section B, significantly suppressing uneven coloring.

[0138] As described above, the detection confirmation portion B in the first layer 10 and the liquid receiving portion A, liquid circulation portion D, and liquid flow path E in the second layer 20 are formed, for example, from a material M that allows the flow of the test liquid by capillary action. Meanwhile, the liquid non-circulating portion X in the first layer 10 and the liquid non-circulating portion Y in the second layer 20 are formed from a material M' that does not allow the flow of the test liquid, for example, by impregnating the material M with a hydrophobic material.

[0139] In the inspection chip, the material M' of the front-side liquid non-circulating portion X and the back-side liquid non-circulating portion Y is preferably colored so that the inspector can easily visually confirm the front-side liquid receiving portion A and the detection confirmation portion B.

[0140] For example, from the perspective of fail-safe, the inspection chip having the third type is particularly useful when it is desired to arrange the liquid receiving part A and the detection confirmation part B on different surfaces.

[0141] Except for the above, description of matters common to the first embodiment will be omitted.

[0142] Furthermore, the inspection chip of the present invention can appropriately have the following features. Hereinafter, the first aspect will be described as the basic feature, but any feature can be applied to the second and third aspects.

[0143] Figure 9 This is a schematic plan view of the front and back surfaces of the inspection chip 1 according to one embodiment. Figure 9 The inspection chip 1 shown has the following features Figure 2Similarly, the liquid-flowing portion D provided on the second layer 20 disposed on the back side has an annular structure and includes a liquid-impermeable portion D' formed inside. In this inspection chip 1, the presence of the liquid-impermeable portion D' allows the test liquid to flow from the outer portion toward the center of the detection confirmation portion B as it passes from the liquid-flowing portion D toward the detection confirmation portion B. This allows the color-developing portion to be further concentrated near the center of the detection confirmation portion B, significantly reducing uneven color development.

[0144] In the above-described inspection chip 1, the annular liquid-flowing portion D can have any contour shape, such as circular, elliptical, or rectangular, but preferably has a contour shape substantially identical to that of the detection confirmation portion B when viewed in plan view of the inspection chip. Furthermore, the liquid-impermeable portion D' preferably has a shape that is a reduction of the contour shape of the liquid-flowing portion D when viewed in plan view of the inspection chip. Furthermore, to avoid hindering colorimetric confirmation in the detection confirmation portion B, the liquid-impermeable portion D' is preferably white, transparent, or uncolored.

[0145] Figure 10 It is a schematic plan view of the front and back surfaces of an inspection chip 1 according to another embodiment. Figure 10 The inspection chip 1 shown has a second layer 20 arranged on the back side and has a plurality of ( Figure 10 The characteristics of the liquid flow path E are E1 and E2, except for this point, Figure 2 Similarly, in this inspection chip 1, the presence of multiple liquid flow paths E allows the momentum of the liquid flows from each liquid flow path E to cancel each other out as the test liquid flows from the liquid circulation portion D toward the detection confirmation portion B, thereby promoting liquid flow in the thickness direction of the inspection chip 1. Consequently, the color-developing portion can be further concentrated near the center of the detection confirmation portion B, significantly suppressing uneven color development.

[0146] Regarding the above features, in the case of the inspection chip of the second embodiment, a plurality of liquid flow paths F can be provided as many as the number of liquid flow paths E, and the plurality of liquid flow paths F in the first layer 10 can be connected to the plurality of liquid flow paths E in the second layer 20 .

[0147] Figure 11 It is a schematic plan view of the front and back surfaces of an inspection chip 1 according to another embodiment. Figure 11 The inspection chip 1 shown is combined with Figure 9 The features shown and Figure 10 In the inspection chip 1, color unevenness can also be suppressed more significantly.

[0148] Figure 12 It is a schematic plan view of the front and back surfaces of an inspection chip 1 according to another embodiment. Figure 12The inspection chip 1 shown has a feature that the second layer 20 arranged on the back side has three (in addition to E1 and E2, there is also E3) liquid flow paths E. Except for this point, it is similar to the Figure 11 At this time, Figure 12 In the inspection chip 1 shown, three liquid flow paths E are connected to the liquid flow portion D so as to face each other. In this inspection chip 1 as well, color unevenness can be further significantly suppressed.

[0149] Figure 13 It is a schematic plan view of the front and back surfaces of an inspection chip 1 according to another embodiment. Figure 13 The inspection chip 1 shown has a feature that the liquid flow path E3 is branched into two (E31 and E32) and connected to the liquid flow part D. Figure 12 In the inspection chip 1 as well, color unevenness can be suppressed even more significantly.

[0150] Figure 14 It is a schematic plan view of the front and back surfaces of an inspection chip 1 according to another embodiment. Figure 14 The inspection chip 1 shown has a feature of having two (E3 and E4) liquid flow paths E in addition to the liquid flow path E1 and the liquid flow path E2. Figure 11 At this time, Figure 14 In the inspection chip 1 shown, four liquid flow paths E are connected to the liquid flow portion D so as to face each other. In this inspection chip 1 as well, color unevenness can be further significantly suppressed.

[0151] In the inspection chip 1 described above, from the perspective of suppressing an increase in the amount of test liquid required for inspection, the number of liquid flow paths E (and liquid flow paths F in the case of the second embodiment) is preferably 4 or less, more preferably 3 or less, and even more preferably 2. Furthermore, the number of locations where the liquid flow paths E connect to the liquid circulation portion D is preferably 4 or less, more preferably 3 or less, and even more preferably 2.

[0152] In addition, in the above-mentioned inspection chip 1, it is preferable that Figures 10 to 14 As shown, at least two of the multiple liquid flow paths E are connected to the liquid circulation section D so as to face each other. Consequently, as the test liquid flows from the liquid circulation section D toward the detection confirmation section B, the flow from each liquid flow path E is concentrated near the center of the liquid circulation section D, thereby promoting the flow of liquid in the thickness direction of the inspection chip 1. Consequently, the coloring area can be further retained near the center of the detection confirmation section B, significantly reducing uneven coloring.

[0153] In addition, in the above-mentioned inspection chip 1, it is preferable that Figures 10 to 14As shown, at least two of the multiple liquid flow paths E have substantially the same shape. In this case, the liquid flowing through the liquid flow path E can reach the liquid flow portion D and the detection confirmation portion B almost simultaneously, thereby avoiding uneven flow and further significantly suppressing uneven color development.

[0154] When the inspection chip 1 is formed from a raw material M (a raw material that allows the flow of a test liquid by capillary action) and a raw material M' (a raw material that does not allow the flow of a test liquid by impregnating the raw material M with a hydrophobic material), the impregnation rate of the hydrophobic material into the raw material M' is preferably within a range of 14% to 32%. By manufacturing the inspection chip with an impregnation rate of 14% or more, the wall surface of the flow path for the test liquid (the interface between the raw material M and the raw material M') becomes sufficiently uniform, allowing for smoother flow of the liquid from the liquid receiving portion A to the detection confirmation portion B. Furthermore, by manufacturing the inspection chip with an impregnation rate of 32% or less, problems such as clogging caused by impregnation of the raw material M with the hydrophobic material can be fully avoided, allowing for a more reliable inspection chip having a desired flow path structure.

[0155] It should be noted that the above-mentioned impregnation rate refers to the impregnation rate of the material M′ in the region formed of the material M′ over the entire thickness direction of the inspection chip 1 .

[0156] The above-mentioned impregnation rate can be considered as 100% if the material M is impregnated with a hydrophobic material heated to a sufficiently low viscosity (e.g., heated to 120°C), then maintained at that temperature for a sufficient time (e.g., 3 minutes). More specifically, the above-mentioned impregnation rate can be determined by the method described in the Examples.

[0157] The above-mentioned impregnation rate can be adjusted by, for example, adjusting the amount of the impregnated hydrophobic material (such as the thickness of the hydrophobic film).

[0158] In the inspection chip 1 as described above, the ratio of the thickness of the second layer 20 (t2) to the thickness of the first layer 10 (t1) (the thickness of the second layer / the thickness of the first layer), that is, t2 / t1, is preferably greater than 0.56 and less than 2.2. By manufacturing the inspection chip in such a manner that t2 / t1 is greater than 0.56 and less than 2.2, the desired flow path structure can be more reliably formed in the obtained inspection chip. In particular, in the case of manufacturing the inspection chip using the inspection chip manufacturing method described later, by manufacturing the inspection chip in such a manner that t2 / t1 is greater than 0.56 and less than 2.2, it is possible to fully avoid undesirable conditions such as clogging when the hydrophobic material is impregnated into the sheet-like raw material, and it is possible to effectively improve the speed and / or speed stability of the liquid flow from the liquid receiving part A to the detection confirmation part B. From the same point of view, t2 / t1 is more preferably greater than 1.0, that is, as Figure 15 As shown, the thickness t2 of the second layer 20 is greater than the thickness t1 of the first layer 10, and is more preferably 1.3 or greater, and even more preferably 1.8 or greater. t2 / t1 is not particularly limited and can be 3.0 or less.

[0159] Furthermore, the inspection chip 1 can be manufactured, for example, by forming a first layer 10 by forming a predetermined portion (such as the detection confirmation portion B) on a sheet material, and forming a second layer 20 by forming a predetermined portion (such as the liquid flow portion D) on another sheet material, and then stacking these two sheet materials. Alternatively, the inspection chip 1 can be manufactured by forming the first layer 10 by forming a predetermined portion on a portion of a sheet material, and forming the second layer 20 by forming a predetermined portion on another portion of the sheet material, and then folding the sheet material while adjusting the positions of the first and second layers. However, the inspection chip 1 of this embodiment is preferably manufactured by forming the first layer on one side of a sheet material and the second layer on the other side. The inspection chip of this embodiment, in which the first layer and the second layer are formed on both sides of a sheet of raw material, has the following various advantages: (1) the time and cost of stacking (or folding) can be avoided; (2) the flow of the inspection liquid based on the capillary phenomenon can be reliably carried out between the first layer and the second layer; (3) there is no need for a clamp for maintaining the stacking (or folding) of the sheet of raw material, so it is easy to discard.

[0160] The inspection chip 1 in which the first layer and the second layer are formed on both sides of a single sheet-like material can be manufactured by, for example, a method for manufacturing an inspection chip to be described later.

[0161] (Inspection of chip manufacturing methods)

[0162] A method for manufacturing an inspection chip according to one embodiment of the present invention is characterized by comprising:

[0163] a film forming step of forming a first hydrophobic film on the first substrate and a second hydrophobic film on the second substrate using a hydrophobic material;

[0164] A first printing step of using the first hydrophobic film on the first substrate to print on a first sacrificial substrate in a manner that becomes an inverse design of the first layer of the inspection chip;

[0165] a second printing step of using the second hydrophobic film on the second substrate to print on a second sacrificial substrate in a manner that becomes an inverse design of the second layer of the inspection chip;

[0166] a first transfer step of transferring the first hydrophobic film after the first printing step to one side of a sheet-like material and impregnating the sheet-like material with the first hydrophobic film; and

[0167] In the second transfer step, the second hydrophobic film after the second printing step is transferred to the other side of the one sheet-like material and is impregnated into the sheet-like material.

[0168] According to this manufacturing method, the inspection chip can be manufactured simply, with high precision, and at low cost.

[0169] <Film Formation Step>

[0170] In the film formation step, a first hydrophobic film is formed on the first substrate using a hydrophobic material, and a second hydrophobic film is formed on the second substrate.

[0171] The hydrophobic material may be mixed with a colorant. Furthermore, the hydrophobic material may be appropriately mixed with a viscosity-adjusting component (e.g., a resin), a dispersing aid, a filler, etc. The hydrophobic material and colorant are as described above for the inspection chip.

[0172] The hydrophobic material is preferably preheated to melt it when forming a film. The heating temperature can be appropriately set considering the melting point of the hydrophobic material and the viscosity adjusting component. In addition, regarding the viscosity when the hydrophobic material is melted, the thickness, unit area weight (density) of the sheet material to be used can be appropriately selected so that it can be impregnated in the sheet material as desired.

[0173] The viscosity of the hydrophobic material is not particularly limited, but from the perspective of fully avoiding problems such as clogging during impregnation, the viscosity is preferably 140° C. and a shear rate of 3000 s. -1 The viscosity at 100 mPa·s or less is preferably 100 mPa·s or less, more preferably 50 mPa·s or less, and further preferably 30 mPa·s or less.

[0174] The first and second substrates are not components of the final inspection chip, but are one of the components used to manufacture the inspection chip. For example, the first and second substrates can be made of polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), or cellophane. The first and second substrates can have any shape, such as a strip or film. Furthermore, the first and second substrates can be the same substrate.

[0175] In the film formation step, the hydrophobic material is applied to form a hydrophobic film on the first and second substrates. It should be noted that the first and second substrates are preferably heated and maintained prior to application. The thickness of the first and second hydrophobic films formed can be appropriately selected based on factors such as the thickness of the sheet material to be used.

[0176] In particular, the ratio of the thickness of the second hydrophobic film (t2') to the thickness of the first hydrophobic film (t1') (the thickness of the second hydrophobic film / the thickness of the first hydrophobic film), i.e., t2' / t1', is preferably 0.56 or more and 2.2 or less. By setting t2' / t1' to 0.56 or more and 2.2 or less, it is possible to fully avoid undesirable conditions such as clogging when the hydrophobic material is impregnated into the sheet-like raw material in subsequent steps, and it is possible to fully improve the speed and / or speed stability of the flow of liquid from the liquid receiving part A to the detection confirmation part B. From the same point of view, t2' / t1' is more preferably greater than 1.0, more preferably greater than 1.3, and even more preferably greater than 1.8. In addition, t2' / t1' is not particularly limited and can be set to 3.0 or less.

[0177] <First Printing Step and Second Printing Step>

[0178] In the first printing step, the first hydrophobic film formed on the first substrate is printed on the first sacrificial substrate. In the second printing step, the second hydrophobic film formed on the second substrate is printed on the second sacrificial substrate.

[0179] The first and second sacrificial substrates are not components of the final inspection chip, but rather are components used to manufacture the inspection chip. The first and second sacrificial substrates are preferably general-purpose substrates capable of high-precision printing, such as high-quality paper, coated paper, and synthetic paper. The first and second sacrificial substrates can be the same substrate.

[0180] There is no particular limitation on the printing of the first sacrificial substrate and the printing of the second sacrificial substrate. For example, a label printer commonly used as an office supply can be preferably used. Then, in the first printing process, the first hydrophobic film on the first substrate is used to print on the first sacrificial substrate in a manner that is an inverted design of the first layer of the inspection chip. In addition, in the second printing process, the second hydrophobic film on the second substrate is used to print on the second sacrificial substrate in a manner that is an inverted design of the second layer of the inspection chip. In this regard, if we cite Figure 2 Taking the manufacturing of the inspection chip shown as an example, the design printed on the first sacrificial substrate includes a printed film corresponding to the liquid receiving portion A and the detection confirmation portion B. Furthermore, the design printed on the second sacrificial substrate includes a printed film corresponding to the liquid flow portion C, the liquid flow portion D, and the liquid flow path E.

[0181] In addition, the design of printing can be prepared in advance, for example, by a personal computer, and the data can be imported into the printing device. In addition, the first printing step and the second printing step can also be performed simultaneously.

[0182] <First Transfer Step and Second Transfer Step>

[0183] In the first transfer step, the first hydrophobic film, after the first printing step, is transferred to one surface of a sheet material and impregnated with the sheet material. Separately, in the second transfer step, the second hydrophobic film, after the second printing step, is transferred to the other surface of the sheet material and impregnated with the sheet material. This forms a first layer derived from the first hydrophobic film and a second layer derived from the second hydrophobic film.

[0184] The hydrophobic film can be transferred using a transfer device such as a laminator. When transferring the first hydrophobic film onto the first substrate and the second hydrophobic film onto the second substrate, it is preferable to appropriately adjust the transfer positions according to the desired design of the inspection chip.

[0185] Regarding the sheet-like raw material, it is as described above regarding the raw material M.

[0186] The impregnation of the sheet-like material with the hydrophobic film can be achieved, for example, by heating. In this regard, for example, if a transfer device such as a heatable laminator is used, both transfer and impregnation of the hydrophobic film can be performed.

[0187] Here, during the first and second transfer steps, the impregnation is performed so that at least a portion of the first hydrophobic film transferred from the first substrate and the second hydrophobic film transferred from the second substrate come into contact with each other within the material M. In other words, the portion of the sheet material to which the hydrophobic film is transferred on both sides, as viewed in the thickness direction, is impregnated with the hydrophobic film throughout its entire thickness. On the other hand, the portion of the sheet material to which the hydrophobic film is transferred only on one surface, as viewed in the thickness direction, is not impregnated with the other surface. This adjustment can be achieved, for example, by appropriately adjusting the viscosity of the hydrophobic material, the thickness of the sheet material, the thickness of the hydrophobic film, and the like.

[0188] In the first and second transfer steps, the transferred hydrophobic film can be completely impregnated into the sheet material. In this case, the thickness of the sheet material remains almost unchanged before and after the first and second transfer steps (although compression by a laminator, etc., may reduce the thickness).

[0189] The first transfer step can be performed before or after the second transfer step. Alternatively, the first and second transfer steps can be performed simultaneously. In this case, the first and second substrates can be used to sandwich the sheet material such that the hydrophobic film contacts the sheet material.

[0190] If the conditions of the first and second transfer steps are the same, the thickness ratio (t2 / t1) of the first and second layers formed after impregnation is maintained at the thickness ratio (t2' / t1') of the hydrophobic films before impregnation.

[0191] After the first transfer step and the second transfer step, the first substrate and the second substrate can be appropriately peeled off. In this way, the inspection chip of this embodiment can be finally obtained.

[0192] In the manufacturing method of the inspection chip of this embodiment, since the above-mentioned printing process and transfer process are performed, even if a sheet-like raw material with a relatively rough surface such as commercially available filter paper is used, transfer defects and voids are less likely to occur, and the inspection chip can be manufactured with higher precision.

[0193] Furthermore, in the method for manufacturing the inspection chip of the present embodiment, the first layer and the second layer having a desired design can be formed without using a mold or the like, and thus manufacturing based on demand is possible.

[0194] In addition, in the manufacturing method of the inspection chip of this embodiment, the first layer and the second layer can be formed on both sides of a sheet of raw material to manufacture the inspection chip. Therefore, compared with the case of using two sheet of raw materials to manufacture the inspection chip (or the case of folding a sheet of raw material to manufacture the inspection chip), there are various advantages such as the following: (1) The time and cost of stacking (or folding) can be avoided; (2) The flow of the inspection liquid based on the capillary phenomenon can be reliably carried out between the first layer and the second layer of the obtained inspection chip; (3) There is no need for a clamp for maintaining the stacking (or folding), so the obtained inspection chip can be easily discarded.

[0195] Example

[0196] Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following Examples.

[0197] (Experiment 1)

[0198] First, the impact of the design (channel structure) of the first and second layers of the inspection chip on color unevenness was studied.

[0199] <Inspection Chip Manufacturing>

[0200] 48 parts by mass of paraffin wax ("Paraffin Wax-155" manufactured by Nippon Seiro Co., Ltd.) as a hydrophobic material, 48 parts by mass of synthetic wax ("DIACARNA (registered trademark) 80" manufactured by Mitsubishi Chemical Corporation) as a hydrophobic material, 2 parts by mass of ethylene-vinyl acetate copolymer resin ("Ultrathene (registered trademark) 681" manufactured by Tosoh Corporation), and 2 parts by mass of carbon black ("MA-100" manufactured by Mitsubishi Chemical Corporation) as a colorant were melt-mixed at 100°C. A sand mill was used to disperse the components. Thus, a hydrophobic material was prepared.

[0201] A substrate ("Lumirror (registered trademark) #5A-F531," manufactured by Toray Industries, Inc., a polyester film, one side heat-resistant treated) was placed on a hot plate maintained at 120°C, with the untreated surface facing upward. Next, the hydrophobic material, maintained in a molten state at 120°C, was applied to the substrate using a Meyer bar to a thickness of approximately 6 to 12 μm, forming strip-shaped hydrophobic films (a first hydrophobic film and a second hydrophobic film).

[0202] Next, using a label printer (manufactured by KINGJIM Co., Ltd., "TEPRA SR750"), the hydrophobic film is printed on the high-quality paper serving as the first sacrificial substrate in a manner that corresponds to the desired design pre-made on the personal computer. Similarly, the hydrophobic film is printed on the high-quality paper serving as the second sacrificial substrate in a manner that corresponds to the desired design pre-made on the personal computer. The two designs printed on the high-quality paper correspond to the designs of the surface (first layer) and back (second layer) of the final inspection chip, respectively, which are inverted. It should be noted that the printed high-quality paper is not particularly used in the subsequent processes.

[0203] Here, in Comparative Example 1, the design of the surface (first layer) and the design of the back (second layer) are as follows. Figure 16 That is, in Comparative Example 1, the liquid receiving portion A and the detection confirmation portion B are connected on the surface by a liquid flow path, and the designs of the surface and the back are roughly the same. In addition, in Examples 1-1 to 1-7, the design of the surface (first layer) and the design of the back (second layer) are respectively as follows: Figure 2 、 9 , 10, 11, 12, 13, and 14.

[0204] Next, using the substrate after the above printing, a filter paper (Whatman grade 41) as a sheet-like raw material M is clamped while appropriately adjusting the position in a manner that the hydrophobic film contacts the filter paper. Then, using a laminator maintained at 90°C, the hydrophobic film is transferred to both sides of the filter paper at one time. Each hydrophobic film is almost completely impregnated with the filter paper from both sides, and the filter paper portion located directly below is hydrophobized. Thus, the first layer with a specified design is formed on the surface side of the filter paper, and the second layer with a specified design is formed on the back side of the filter paper. It should be noted that in the filter paper, when observed in the thickness direction, the parts with the hydrophobic film transferred on both sides are impregnated with the hydrophobic film throughout the thickness direction. In addition, when observed in the thickness direction, the parts with the hydrophobic film transferred only on one surface are not impregnated to the other surface.

[0205] Then, the substrates on both sides are peeled off to finally obtain the inspection chip. It should be noted that the first layer and the second layer in any example are derived from the same hydrophobic film and therefore have the same thickness.

[0206] <Evaluation of color unevenness>

[0207] Each of the obtained inspection chips was placed with the surface (first layer) facing up, and a mark was made with a water-based red fluorescent pen in the center of the detection confirmation area B. Then, three drops of distilled water were added to the liquid receiving area A using a dropper, and changes in the red mark due to the flow of water were observed.

[0208] As a result, in Comparative Example 1 ( Figure 16 ), the red mark located in the center of the detection confirmation section B shifted toward the periphery of the detection confirmation section B (particularly toward the side away from the liquid receiving section A), making the red color difficult to visually confirm. Therefore, the inspection chip of Comparative Example 1 was found to have uneven color development and was therefore unsuitable for quantitative analysis.

[0209] In contrast, in Examples 1-1 to 1-7 ( Figure 2 、 9 1-2 to 1-7 ( Figures 9-14 ), the fluorescent pen mark located in the center of detection confirmation section B remains closer to the center of detection confirmation section B. This is believed to be due to the optimized liquid flow path, which allows water to flow three-dimensionally within the filter paper, compared to Comparative Example 1. Therefore, the inspection chips of Examples 1-1 to 1-7 are believed to significantly suppress color unevenness, and therefore can be expected to be used for quantitative analysis.

[0210] (Experiment 2)

[0211] Next, the relationship between the thicknesses of the first layer and the second layer, which can ensure good liquid flowability, was examined.

[0212] According to the formulation shown in Table 1, a hydrophobic material (ink) was prepared.

[0213] [Table 1]

[0214]

[0215] *1 Paraffin wax: Nippon Seiro Co., Ltd., "Paraffin Wax-135"

[0216] *2 Synthetic wax: "DIACARNA (registered trademark) 30" manufactured by Mitsubishi Chemical Corporation

[0217] *3 Carbon black: MA-100 manufactured by Mitsubishi Chemical Corporation

[0218] *4 Resin: Ultrathene (registered trademark) 722 manufactured by Tosoh Corporation

[0219] The test chip was obtained in substantially the same manner as above except that ink 1 or ink 2 was used as the hydrophobic material, Whatman grade 41 (filter paper #41) or Whatman grade 40 (filter paper #40) was used as the filter paper (raw material M), and the temperature of the laminator was appropriately adjusted. In this case, the design of the first and second layers was as follows: Figure 11In addition, at this time, the thickness of the first hydrophobic film for forming the first layer and the thickness of the second hydrophobic film for forming the second layer are appropriately changed (corresponding to the ratio of the thickness of the first layer to the second layer).

[0220] Each obtained inspection chip was positioned with the surface (first layer) facing upward. Next, approximately 0.3 mL of a solution of aqueous fluorescent ink in distilled water was added dropwise to the liquid receiving portion A using a dropper. The time from the start of addition until the liquid reached the detection confirmation portion B (flow time) was measured. Eight similar measurements were repeated, and the average and standard deviation were calculated. The results are shown in Tables 2 to 5 for each combination of hydrophobic material and filter paper.

[0221] [Table 2]

[0222]

[0223] [Table 3]

[0224]

[0225] [Table 4]

[0226]

[0227] [Table 5]

[0228]

[0229] The examples in Tables 2 to 5 all have good liquid flowability. Therefore, if the ratio of the thickness of the second layer to the thickness of the first layer (second layer thickness / first layer thickness) is at least within the range of 0.56 to 2.2, it can be considered that good liquid flowability is ensured.

[0230] (Experiment 3)

[0231] Next, the impregnation rate of the hydrophobic material that can ensure good liquid flowability was studied.

[0232] Cut the same filter paper (filter paper #41 or filter paper #40) as that used in Experiment 2 into a size of 5 cm × 2 cm, dry it at 120°C for 3 minutes, and measure the dry mass M0 (g). Next, impregnate the filter paper with the same hydrophobic material (ink 1 or ink 2) as that used in Experiment 2, and place it at 120°C for 3 minutes. Use the same filter paper and a glass slide to clamp the impregnated filter paper, and place it at 120°C for 1 minute under a load of 100 gf to remove excess hydrophobic material. Then, measure the mass M1 (g) of the filter paper. Then, calculate the maximum impregnation amount P per unit area from (M1-M0)×1000. max (g / m 2 ).

[0233] In each of Tables 2 to 5, the examples with the smallest and largest combined thicknesses of the first and second hydrophobic films were selected, and the actual impregnation amount P (g / m2) per unit area in the selected examples was calculated using the density of the ink listed in Table 1. 2 Then, (P / P max )×100, and the impregnation rate (%) of the filter paper with the hydrophobic material was calculated. The results are shown in Table 6.

[0234] [Table 6]

[0235]

[0236] From Table 6, it can be seen that as long as the impregnation rate of the hydrophobic material is at least within the range of about 14% to 32%, good liquid flowability can be ensured.

[0237] Industrial applicability

[0238] According to the present invention, a test chip can be provided. This test chip is used to react a target substance contained in a test fluid with a pre-installed labeling medium, and the presence of the target substance is confirmed by the color development caused by this reaction. The test chip significantly suppresses uneven color development. Furthermore, the present invention can provide a method for manufacturing the test chip, enabling simple, high-precision, and low-cost production of the test chip.

[0239] Explanation of symbols

[0240] 1 inspection chip; 10 first layer; 10' preset first layer; 20 second layer; 20' preset second layer; 50 hydrophobic material; A liquid receiving portion; B detection confirmation portion; C, D liquid circulation portion; D' liquid non-circulating portion; E, E1, E2, E3, E4, E31, E32 liquid flow paths; F liquid flow path; M raw material showing the circulation of the inspected liquid; M' raw material not showing the circulation of the inspected liquid; X, Y liquid non-circulating portions.

Claims

1. An inspection chip, characterized in that: It is a sheet-shaped inspection chip. It has a first layer on the front side and a second layer on the back side, The first layer and the second layer are adjacent, Either the first layer or the second layer has a liquid receiving portion A, The first layer at least has a detection confirmation part B, The second layer has at least a liquid flow portion D adjacent to the detection confirmation portion B and a liquid flow path E connected to the liquid flow portion D. The first layer is formed on one surface of a sheet-like material, and the second layer is formed on the other surface of the sheet-like material. The first layer has the liquid receiving portion A separated from the detection confirmation portion B, The second layer has a liquid passing portion C adjacent to the liquid receiving portion A. When the test liquid is dropped into the liquid receiving portion A, the test liquid flows sequentially through the liquid receiving portion A, the liquid flowing portion C, the liquid flow path E, and the liquid flowing portion D to the detection confirmation portion B by capillary action.

2. An inspection chip, characterized in that: It is a sheet-shaped inspection chip. It has a first layer on the front side and a second layer on the back side, The first layer and the second layer are adjacent, Either the first layer or the second layer has a liquid receiving portion A, The first layer at least has a detection confirmation part B, The second layer has at least a liquid flow portion D adjacent to the detection confirmation portion B and a liquid flow path E connected to the liquid flow portion D. The liquid flow portion D is an annular structure with a liquid non-flow portion D' formed inside. The first layer has the liquid receiving portion A separated from the detection confirmation portion B, The second layer has a liquid passing portion C adjacent to the liquid receiving portion A. When the test liquid is dropped into the liquid receiving portion A, the test liquid flows sequentially through the liquid receiving portion A, the liquid flowing portion C, the liquid flow path E, and the liquid flowing portion D to the detection confirmation portion B by capillary action.

3. An inspection chip, characterized in that: It is a sheet-shaped inspection chip. It has a first layer on the front side and a second layer on the back side, The first layer and the second layer are adjacent, Either the first layer or the second layer has a liquid receiving portion A, The first layer at least has a detection confirmation part B, The second layer has at least a liquid flow portion D adjacent to the detection confirmation portion B and a liquid flow path E connected to the liquid flow portion D. The second layer has a plurality of liquid flow paths E. The first layer has the liquid receiving portion A separated from the detection confirmation portion B, The second layer has a liquid passing portion C adjacent to the liquid receiving portion A. When the test liquid is dropped into the liquid receiving portion A, the test liquid flows sequentially through the liquid receiving portion A, the liquid flowing portion C, the liquid flow path E, and the liquid flowing portion D to the detection confirmation portion B by capillary action.

4. The inspection chip according to claim 3, wherein: At least two of the liquid flow paths E are connected to the liquid flow portion D so as to face each other.

5. The inspection chip according to claim 3 or 4, wherein: At least two of the liquid flow paths E have substantially the same shape.

6. The inspection chip according to any one of claims 1 to 4, wherein The first layer also has a liquid flow path F connected to the liquid receiving part A. When the test liquid is dropped into the liquid receiving part A, the test liquid flows sequentially through the liquid receiving part A, the liquid flow path F, the liquid flow path E, and the liquid flow part D to the detection confirmation part B by capillary action.

7. The inspection chip according to any one of claims 1 to 4, wherein The second layer has the liquid receiving portion A.

8. The inspection chip according to any one of claims 1 to 4, wherein The liquid receiving portion A, any of the liquid circulating portions C, any of the liquid flow paths F, the liquid flow paths E, the liquid circulating portion D, and the detection confirmation portion B are formed of a material M that allows the liquid to flow by capillary action. The portion other than the material M is formed of a material M′ in which the material M is impregnated with a hydrophobic material and in which no test liquid flows.

9. The inspection chip according to claim 8, wherein: The raw material M is filter paper.

10. The inspection chip according to claim 8, wherein: The impregnation rate of the hydrophobic material in the raw material M′ into the raw material M is 14% or more and 32% or less.

11. The inspection chip according to any one of claims 1 to 4, wherein The ratio of the thickness of the second layer to the thickness of the first layer, ie, the thickness of the second layer / the thickness of the first layer, is 0.56 or more and 2.2 or less.

12. The inspection chip according to any one of claims 1 to 4, wherein A color development reaction caused by the detection target substance occurs in the detection confirmation section B.

13. A method for manufacturing an inspection chip, characterized in that: The method for manufacturing the inspection chip according to any one of claims 1 to 12, comprising: a film forming step of forming a first hydrophobic film on the first substrate and a second hydrophobic film on the second substrate using a hydrophobic material; a first printing step of using the first hydrophobic film on the first substrate to print on the first sacrificial substrate in a manner that becomes an inverse design of the first layer of the inspection chip; a second printing step of using the second hydrophobic film on the second substrate to print on a second sacrificial substrate in a manner that becomes an inverse design of the second layer of the inspection chip; a first transfer step of transferring the first hydrophobic film after the first printing step to one surface of a sheet-like material and impregnating the sheet-like material with the first hydrophobic film; and In the second transfer step, the second hydrophobic film after the second printing step is transferred to the other surface of the one sheet-like material, and the second hydrophobic film is impregnated into the sheet-like material.

14. The method for manufacturing an inspection chip according to claim 13, wherein: A ratio of the thickness of the second hydrophobic film to the thickness of the first hydrophobic film, ie, thickness of the second hydrophobic film / thickness of the first hydrophobic film, is 0.56 or more and 2.2 or less.

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