Testing method, testing system, and antigen testing element

Abstract

In this test method, a periodically varying voltage with a periodically reversing polarity is applied at each of the following: between an electrode pair (32A, 33A) of a first test element (3A) that comprises a test specimen (4) of a sample mixed in a solvent and the electrode pair (32A, 33A) positioned so as to sandwich a space (SP1) in which the test specimen (4) is enclosed; and between an electrode pair (32B, 33B) of a second test element (3B) that comprises the test specimen (4) and the electrode pair (32B, 33B) positioned so as to sandwich a space (SP1) in which the test specimen (4) is enclosed. This test method tests for the presence / absence of antigen (40) in a sample by comparing the current flowing in the first test element (3A) due to the applied voltage, with the current flowing in the second test element (3B) due to the applied voltage. The second test element (3B) comprises antibody (38) that is immobilized in a state of exposure to the test specimen (4) and that specifically binds to the antigen (40). The first test element (3A) does not have the antibody (38).

Description

[Technical Field]

[0001] The present disclosure relates to a testing method, a testing system, and an antigen testing element for testing the presence or absence of an antigen that may be contained in a sample. [Background technology]

[0002] Patent Document 1 discloses a method for measuring impurity ions in a liquid by applying a triangular wave voltage signal between a first electrode and a second electrode in a state in which the liquid is sealed in a measurement container having the first electrode and the second electrode, and detecting a current signal that flows through the liquid as the voltage is applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 167186 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique disclosed in Patent Document 1 has a problem in that it is not possible to test for the presence or absence of antigens that may be contained in a sample.

[0005] Therefore, the present disclosure provides a testing method, testing system, and antigen testing element that can test for the presence or absence of an antigen that may be contained in a sample. [Means for solving the problem]

[0006] To achieve the above object, a testing method according to one aspect of the present disclosure includes applying a periodically changing voltage, the voltage being periodically reversed in polarity, between a pair of electrodes of a first testing element including a sample containing a solvent and a space in which the sample is enclosed, a pair of electrodes positioned to sandwich the space, and an insulating layer disposed on at least one of the sides of the space, and between a pair of electrodes of a second testing element including a pair of electrodes positioned to sandwich the space in which the sample is enclosed, and an insulating layer disposed on at least one of the sides of the space. The testing method tests for the presence or absence of a charged antigen in the sample by comparing a current flowing through the first testing element upon application of the voltage with a current flowing through the second testing element upon application of the voltage. The second testing element includes an antibody immobilized in a manner exposed to the sample and capable of specifically binding to the antigen, while the first testing element does not include the antibody.

[0007] To achieve the above object, a testing system according to one aspect of the present disclosure includes a voltage application unit and a measurement unit. The voltage application unit applies a voltage that periodically changes and periodically reverses polarity between a pair of electrodes of a first testing element, the first testing element including a sample containing a solvent and a sample, a pair of electrodes positioned to sandwich a space in which the sample is sealed, and an insulating layer disposed on at least one of the sides of the space. The voltage application unit also applies a voltage that periodically changes and periodically reverses polarity between a pair of electrodes of a second testing element, the second testing element including a pair of electrodes positioned to sandwich the space in which the sample is sealed, and an insulating layer disposed on at least one of the sides of the space. The measurement unit tests for the presence or absence of a charged antigen in the sample by comparing a current flowing through the first testing element upon application of the voltage with a current flowing through the second testing element upon application of the voltage. The second testing element includes an antibody that is immobilized in a manner exposed to the sample and specifically binds to the antigen, while the first testing element does not include the antibody.

[0008] Furthermore, to achieve the above object, an antigen test element according to one embodiment of the present disclosure comprises a first test element and a second test element. The first test element comprises a sample obtained by mixing a specimen with a solvent, a pair of electrodes positioned to sandwich a space in which the specimen is sealed, and an insulating layer disposed on at least one of the sides sandwiching the space. The second test element comprises the specimen, a pair of electrodes positioned to sandwich the space in which the specimen is sealed, and an insulating layer disposed on at least one of the sides sandwiching the space. The second test element comprises an antibody that is immobilized in a manner exposed to the specimen and specifically binds to a charged antigen in the specimen, while the first test element does not comprise the antibody. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an inspection system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an antigen test element according to an embodiment. [Figure 3] FIG. 3 is a flowchart showing an example of an inspection method according to an embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a measurement result expected by the inspection method according to the embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the configuration of an inspection system according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0011] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, etc. shown in the following embodiments are merely examples and are not intended to limit the scope of the claims. Furthermore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components. Furthermore, each drawing is not necessarily an exact illustration. In each drawing, substantially identical components are assigned the same reference numerals, and redundant explanations are omitted or simplified.

[0012] (Embodiment) First, a testing method and testing system according to an embodiment will be described. Fig. 1 is a schematic diagram showing the configuration of a testing system 100 according to an embodiment. The testing method and testing system 100 according to the embodiment tests for the presence or absence of an antigen 40 that may be contained in a sample. Specifically, the testing method and testing system 100 according to the embodiment tests for an antigen testing element 3 containing a sample by applying a voltage to a pair of electrodes 32, 33 (described later) of the antigen testing element 3.

[0013] The specimen is a bodily fluid of the subject, such as the subject's saliva or a nasal swab of the subject. The antigen 40 is a particularly charged antigen and may include, for example, a virus. In this embodiment, the antigen 40 is assumed to be Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which causes novel coronavirus disease 2019 (COVID-19).

[0014] As shown in FIG. 1, the testing system 100 includes a voltage application unit 1 and two measurement units 2. Hereinafter, when distinguishing between the two measurement units 2, one measurement unit 2 will be referred to as the "first measurement unit 2A" and the other measurement unit 2 as the "second measurement unit 2B." In addition, in the embodiment, the antigen testing element 3 used in the testing system 100 has two elements. Hereinafter, when distinguishing between the two elements, one element will be referred to as the "first testing element 3A" and the other element will be referred to as the "second testing element 3B."

[0015] The voltage application unit 1 is connected between a pair of electrodes 32, 33 of the antigen test element 3, and applies a voltage that changes periodically and whose polarity is periodically reversed between the pair of electrodes 32, 33. In this embodiment, a first end of the voltage application unit 1 is connected to an electrode 32A of the first test element 3A and an electrode 32B of the second test element 3B. A second end of the voltage application unit 1 is connected to an electrode 33A of the first test element 3A via a first measurement unit 2A, and to an electrode 33B of the second test element 3B via a second measurement unit 2B.

[0016] In this embodiment, the voltage application unit 1 is a function generator that generates a triangular wave voltage as a voltage that changes periodically and whose polarity is periodically reversed, and applies the generated triangular wave voltage between the pair of electrodes 32A, 33A of the first test element 3A and between the pair of electrodes 32B, 33B of the second test element 3B. The triangular wave voltage has, as an example, a frequency of 1 Hz and an amplitude of ±10 V. Note that both the frequency and amplitude of the triangular wave voltage are examples and are not limited to these.

[0017] The measurement unit 2 tests for the presence or absence of an antigen 40 that may be contained in a sample by measuring the current that flows through the antigen test element 3 when a voltage is applied by the voltage application unit 1. In this embodiment, the measurement unit 2 includes an IV converter 21 and a voltmeter 22.

[0018] The IV converter 21 is connected in series with the pair of electrodes 32, 33 of the antigen test element 3, and converts the current flowing through the antigen test element 3 into a voltage. Specifically, the IV converter 21A of the first measurement unit 2A is connected in series with the pair of electrodes 32A, 33A of the first test element 3A, and converts the current flowing through the first test element 3A into a voltage. Furthermore, the IV converter 21B of the second measurement unit 2B is connected in series with the pair of electrodes 32B, 33B of the second test element 3B, and converts the current flowing through the second test element 3B into a voltage.

[0019] The voltmeter 22 measures the voltage converted by the IV converter 21. That is, the measurement unit 2 measures the current flowing through the antigen test element 3 by measuring the voltage converted by the IV converter 21 with the voltmeter 22. Specifically, the first measurement unit 2A measures the voltage converted by the IV converter 21A of the first measurement unit 2A with the voltmeter 22A of the first measurement unit 2A, thereby measuring the current flowing through the first test element 3A. Furthermore, the second measurement unit 2B measures the voltage converted by the IV converter 21B of the second measurement unit 2B with the voltmeter 22B of the second measurement unit 2B, thereby measuring the current flowing through the second test element 3B.

[0020] As will be described in detail later, the measurement unit 2 measures the current flowing through the antigen test element 3 to test for the presence or absence of an antigen 40 that may be contained in the sample.

[0021] Fig. 2 is a schematic diagram showing an antigen test element 3 according to an embodiment. Fig. 2(a) is a plan view of a first test element 3A of the antigen test element 3, and Fig. 2(b) is a cross-sectional view of the first test element 3A. Fig. 2(c) is a plan view of a second test element 3B of the antigen test element 3, and Fig. 2(d) is a cross-sectional view of the second test element 3B.

[0022] As shown in FIGS. 2A and 2B, the first testing element 3A includes a sealing material 31 (31A), a pair of electrodes 32 and 33 (32A and 33A), a pair of insulating layers 34 and 35 (34A and 35A), a pair of glass substrates 36 and 37 (36A and 37A), and a sample 4. As shown in FIGS. 2C and 2D, the second testing element 3B includes a sealing material 31 (31B), a pair of electrodes 32 and 33 (32B and 33B), a pair of insulating layers 34 and 35 (34B and 35B), a pair of glass substrates 36 and 37 (36B and 37B), and a sample 4. The sample 4 is prepared by mixing a specimen with a solvent. The solvent may be, for example, liquid crystal, xylene, or toluene.

[0023] The pair of electrodes 32, 33 are both ITO (Indium Tin Oxide) electrodes and are transparent electrodes. The material constituting the pair of electrodes 32, 33 is not particularly limited. One (here, the upper) electrode 32 of the pair of electrodes 32, 33 is formed on one surface (here, the lower surface) of one (here, the upper) glass substrate 36 of the pair of glass substrates 36, 37. The other (here, the lower) electrode 33 of the pair of electrodes 32, 33 is formed on one surface (here, the upper surface) of the other (here, the lower) glass substrate 37 of the pair of glass substrates 36, 37.

[0024] The pair of insulating layers 34, 35 are both SiN (silicon nitride) insulating films. The material constituting the pair of insulating layers 34, 35 is not particularly limited. One (here, the upper) insulating layer 34 of the pair of insulating layers 34, 35 is formed on one surface (here, the lower surface) of one (here, the upper) electrode 32 of the pair of electrodes 32, 33. The other (here, the lower) insulating layer 35 of the pair of insulating layers 34, 35 is formed on one surface (here, the upper surface) of the other (here, the lower) electrode 33 of the pair of electrodes 32, 33. The pair of insulating layers 34, 35 are arranged opposite to each other across a space SP1 in which the sample 4 is sealed.

[0025] The sealant 31 is applied between the pair of insulating layers 34, 35, the pair of electrodes 32, 33, and the pair of glass substrates 36, 37 so as to cover the space SP1. That is, the space is formed by the pair of insulating layers 34, 35, the pair of electrodes 32, 33, the pair of glass substrates 36, 37, and the sealant 31. A portion of each of the pair of electrodes 32, 33 is exposed to the outside, and the voltage application unit 1 and the measurement unit 2 can be electrically connected to the exposed portions via electric wires.

[0026] The first testing element 3A and the second testing element 3B differ in the following respects. Specifically, in the second testing element 3B, a large number of antibodies 38 are embedded (immobilized) in one (here, the lower) insulating layer 35B of the pair of insulating layers 34B, 35B in a manner that exposes them to the sample 4, whereas the first testing element 3A does not include antibodies 38. The antibodies 38 are antibodies that specifically bind to antigens 40 that may be contained in a specimen. As already mentioned, in this embodiment, the antigens 40 are assumed to be SARS-coronavirus 2, which causes COVID-19. Therefore, in this embodiment, the antibodies 38 are antibodies against the spike (S) protein present on the surface of SARS-coronavirus 2.

[0027] A method for producing the antigen test element 3 will be described below. First, a specimen and a solvent are prepared, and the specimen is mixed with the solvent to produce the sample 4. Next, an antigen test element 3 with an empty space SP1 is prepared, and the produced sample 4 is sealed inside the antigen test element 3. In this embodiment, a portion of the produced sample 4 is sealed inside the first test element 3A, and the remainder of the sample 4 is sealed inside the second test element 3B. Here, two injection ports (not shown) are formed in the area of ​​the antigen test element 3 where the sealing material 31 is applied. The produced sample 4 is sealed into the antigen test element 3 from at least one of these two injection ports by utilizing capillary action. By going through the above steps, it is possible to produce an antigen test element 3 in which the sample 4 is sealed.

[0028] <Method> The operation of the testing system 100 according to the embodiment, that is, the testing method, will be described below with reference to Fig. 3. Fig. 3 is a flowchart showing an example of the testing method according to the embodiment. Although Fig. 3 also includes a step of fabricating the antigen testing element 3 described above, the testing method according to the embodiment does not necessarily include the step of fabricating the antigen testing element 3 (steps S1 and S2 described below).

[0029] First, a specimen is mixed with a solvent to prepare a sample 4 (step S1). Next, the prepared sample 4 is sealed in an antigen testing element 3 with an empty space SP1, thereby preparing an antigen testing element 3 in which the sample 4 is sealed (step S2). Here, a first testing element 3A and a second testing element 3B in which the sample 4 is sealed are prepared.

[0030] Next, the voltage application unit 1 applies a voltage (here, a triangular wave voltage) between the pair of electrodes 32, 33 of the antigen test element 3 (step S3). Here, the voltage application unit 1 simultaneously applies a voltage between the pair of electrodes 32A, 33A of the first test element 3A and between the pair of electrodes 32B, 33B of the second test element 3B.

[0031] Next, the measurement unit 2 measures the current flowing between the pair of electrodes 32, 33 of the antigen test element 3 (step S4). Here, the first measurement unit 2A measures the current flowing between the pair of electrodes 32A, 33A of the first test element 3A. Also, the second measurement unit 2B measures the current flowing between the pair of electrodes 32B, 33B of the second test element 3B.

[0032] Then, based on the current measured by the measurement unit 2, the presence or absence of antigen 40 (here, SARS coronavirus 2) that may be contained in the sample is examined (step S5). Here, the presence or absence of antigen 40 that may be contained in the sample is examined by comparing the current measured by the first measurement unit 2A with the current measured by the second measurement unit 2B.

[0033] A specific method for testing an antigen 40 that may be contained in a sample will be described below with reference to FIG. 4. FIG. 4 is a diagram showing an example of an expected measurement result using the testing method according to the embodiment. FIG. 4 is a diagram showing an example of a graph (VI curve) plotting voltage V (time) versus current I obtained by measuring the displacement current that flows when a triangular wave voltage is applied between the pair of electrodes 32, 33 of the antigen testing element 3. In FIG. 4, the vertical axis represents the current (unit: "A") that flows through the pair of electrodes 32, 33 and the antigen testing element 3, and the horizontal axis represents the voltage (unit: "V") applied between the pair of electrodes 32, 33. In addition, in FIG. 4, the solid line represents the expected measurement result for the first testing element 3A, and the dashed line represents the expected measurement result for the second testing element 3B.

[0034] As shown by the solid line in FIG. 4, a peak in the displacement current (a portion protruding from the parallelogram-shaped graph) occurs in the first testing element 3A. This peak in the displacement current occurs because the antigen 40 has an electric charge, and thus moves in the solvent in response to the applied voltage, similar to ions. On the other hand, as shown by the dashed line in FIG. 4, there is no peak in the displacement current or the peak hardly occurs in the second testing element 3B. This is thought to be because the antigen 40 specifically binds to the antibody 38 and is therefore unable to move in the solvent regardless of the applied voltage.

[0035] Therefore, in the testing method according to the embodiment, the measurement result of the current flowing through the first testing element 3A is compared with the measurement result of the current flowing through the second testing element 3B, and if there is a difference in the displacement current that is equal to or greater than the threshold, it can be determined that the sample contains the antigen 40. On the other hand, if the comparison shows that there is no difference in the displacement current that is equal to or greater than the threshold, in other words, if there is almost no difference in the displacement current, it can be determined that the sample does not contain the antigen 40.

[0036] The knowledge that charged antigens 40 move within a solvent in response to an applied voltage, similar to ions, is disclosed in the following documents 1 and 2. Document 1 is "Kazuki Iwabata et al. 2013 Jpn. J. Appl. Phys. 52 097301." Document 1 shows that DNA moves within a solvent in response to an applied voltage, similar to ions. Document 2 is "Ionic Current: Virus Detection Using Nanopores and Machine Learning, Tsutsui Makusu, Washio Takashi, Kawai Tomoji, The Japan Society of Applied Physics, June 19, 2020." Document 2 shows that viruses move within a solvent in response to an applied voltage, similar to ions. Document 2 is disclosed at the URL: https: / / www.jsap.or.jp / columns-covid19 / covid19#4-3-2.

[0037] <Advantages> The advantages of the testing method and testing system 100 according to the embodiment will be described below, along with a comparison with conventional virus testing methods. Conventional testing methods for SARS-CoV-2, which causes COVID-19, include PCR (Polymerase Chain Reaction) testing, qualitative antigen testing using simple kits, and chemiluminescent enzyme immunoassay (CLEIA).

[0038] While PCR testing can detect the presence or absence of SARS-CoV-2 with relatively high accuracy, it has the drawback of taking a relatively long time to complete the test. Qualitative antigen testing can be performed in about 5 minutes, which is shorter than PCR testing, but it has the drawback of being less accurate in detecting the presence or absence of SARS-CoV-2 compared to PCR testing. The CLEIA method can be performed in about 30 minutes, which is shorter than PCR testing, and can detect the presence or absence of SARS-CoV-2 with the same accuracy as PCR testing, but it has the drawback of taking a longer time to complete the test compared to qualitative antigen testing, and the equipment used for the test is expensive, making it difficult to perform the test easily.

[0039] In contrast, the testing method and testing system 100 according to the embodiment makes it possible to detect viruses, and in turn, charged antigens, by displacement current measurement by modifying the cell (testing element) used in conventional displacement current measurement. Therefore, the testing method and testing system 100 according to the embodiment has the advantage of being able to test for the presence or absence of antigen 40 with relatively high accuracy and being able to perform the test in a shorter time than the PCR test, qualitative antigen test, and CLEIA method described above. The testing method and testing system 100 according to the embodiment also has the advantage of being able to perform the test more easily than the CLEIA method.

[0040] (Variation) The inspection method and inspection system 100 according to the present disclosure have been described above based on the embodiments, but the present disclosure is not limited to the embodiments. As long as they do not deviate from the gist of the present disclosure, various modifications conceivable by a person skilled in the art to the embodiments, or other modifications constructed by combining some of the components of the embodiments, are also included within the scope of the present disclosure.

[0041] In the embodiment, the antigen test element 3 has the first test element 3A and the second test element 3B as separate elements, but this is not limited to this. For example, as shown in FIG. 5, the first test element 3A and the second test element 3B may be configured as a single antigen test element 3C that shares a space SP1 in which the sample 4 is sealed. FIG. 5 is a schematic diagram showing the configuration of a test system 100A according to a modified embodiment. Note that the test system 100A shown in FIG. 5 differs from the test system 100 according to the embodiment only in that the antigen test element 3 used is the antigen test element 3C.

[0042] As shown in FIG. 5, the antigen test element 3C is configured by connecting a first test element 3A and a second test element 3B to each other. In the antigen test element 3C, one electrode 32A of the pair of electrodes 32A, 33A of the first test element 3A and one electrode 32B of the pair of electrodes 32B, 33B of the second test element 3B are configured as a single common electrode 32C. In addition, in the antigen test element 3C, a large number of antibodies 38 are embedded in a portion of the lower insulating layer corresponding to the insulating layer 35B, but no antibodies 38 are embedded in other portions. In addition, in the antigen test element 3C, no antibodies 38 are embedded in any portion of the upper insulating layer 34C.

[0043] When performing a test using the above-mentioned antigen test element 3C, there is an advantage that the test is easier to perform because the effort of preparing an antigen test element containing sample 4 is eliminated compared to when performing a test using elements in which the first test element 3A and the second test element 3B are separated from each other.

[0044] In the antigen test element 3C, the number of lower electrodes, that is, the electrodes connected to the measurement unit 2, is not limited to two, but may be three or more.

[0045] Furthermore, the antigen test element 3C may have multiple second test elements 3B rather than just one. The multiple second test elements 3B may each contain different types of antibodies. For example, if the antigen test element 3C has two second test elements 3B, one second test element 3B may contain a first antibody that specifically binds to a first antigen, and the other second test element 3B may contain a second antibody that specifically binds to a second antigen. In this case, different measuring units 2 are connected to the electrodes 33B of the two second test elements 3B. When the antigen test element 3C is configured in this manner, it is possible to determine which of multiple types of antigens 40 is contained in the sample 4 by measuring the current once.

[0046] In the embodiment, the antibody 38 is embedded in the lower insulating layer 35B of the pair of insulating layers 34B, 35B of the second testing element 3B, but this is not limiting. For example, the antibody 38 may be embedded in the upper insulating layer 34B of the second testing element 3B, or the antibody 38 may be embedded in both insulating layers 34B, 35B.

[0047] In the embodiment, the antibody 38 is immobilized by being embedded in the insulating layer 35B, but this is not limiting. That is, the antibody 38 may be immobilized in a manner that exposes it to the sample 4 by any means other than embedding it in the insulating layer 35B.

[0048] In the embodiment, the antigen test element 3 includes a pair of insulating layers 34, 35, but is not limited to this. For example, the antigen test element 3 may include at least one of the pair of insulating layers 34, 35 that does not include the antibody 38 (here, the insulating layer 34). In other words, the first test element 3A may include only the insulating layer 34A of the pair of insulating layers 34A, 35A, and the second test element 3B may include only the insulating layer 35B of the pair of insulating layers 34B, 35B.

[0049] In the embodiment, the number of measuring units 2 is two for each test element 3A, but this is not limited to this. For example, the number of measuring units 2 may be one. In other words, in the embodiment, the currents of the first test element 3A and the second test element 3B are measured simultaneously, but the currents of the first test element 3A and the second test element 3B do not have to be measured simultaneously. In this case, the measuring unit 2 may first be connected to the electrode 33A of the first test element 3A to measure the current flowing through the first test element 3A, and then the measuring unit 2 may be connected to the electrode 33B of the second test element 3B to measure the current flowing through the second test element 3B.

[0050] In the embodiment, the testing method and testing system 100 test for the presence or absence of antigen 40 in a sample, but this is not limiting. For example, when the sample contains antigen 40, the testing method and testing system 100 may measure the amount of antigen 40 contained in the sample based on the difference between the current flowing through the first testing element 3A and the current flowing through the second testing element 3B. For example, when the measurement results shown in FIG. 4 are obtained, the amount of antigen 40 contained in the sample can be measured by calculating the difference between the area of ​​the peak protruding from the parallelogram-shaped graph in the measurement results of the first testing element 3A and the area of ​​the peak protruding from the parallelogram-shaped graph in the measurement results of the second testing element 3B.

[0051] (summary) As described above, in the testing method according to the first aspect of the present disclosure, a voltage that changes periodically and whose polarity is periodically reversed is applied between the pair of electrodes 32A, 33A of the first testing element 3A, which includes a sample 4 containing a solvent mixed with a specimen, a pair of electrodes 32A, 33A positioned to sandwich the space SP1 in which the sample 4 is sealed, and insulating layers 34A, 35A arranged on at least one of the sides of the space SP1, and between the pair of electrodes 32B, 33B of the second testing element 3B, which includes a pair of electrodes 32B, 33B positioned to sandwich the space SP1 in which the sample 4 is sealed, and insulating layers 34B, 35B arranged on at least one of the sides of the space SP1 (step S3). In this testing method, the presence or absence of a charged antigen 40 in the specimen is tested by comparing the current flowing through the first testing element 3A due to the application of a voltage with the current flowing through the second testing element 3B due to the application of a voltage (steps S4 and S5). The second testing element 3B is immobilized in a manner exposed to the sample 4 and includes an antibody 38 that specifically binds to the antigen 40, while the first testing element 3A does not include the antibody 38.

[0052] This has the advantage that it is possible to test for the presence or absence of antigen 40 that may be contained in the sample.

[0053] In addition, in the inspection method according to the second aspect of the present disclosure, in the first aspect, the step of applying a voltage between a pair of electrodes 32A, 33A of the first inspection element 3A and the step of applying a voltage between a pair of electrodes 32B, 33B of the second inspection element 3B are performed in parallel.

[0054] This has the advantage that the time required to test for the presence or absence of an antigen can be reduced compared to when these steps are performed in order.

[0055] In the testing method according to the third aspect of the present disclosure, in the first or second aspect, the first testing element 3A and the second testing element 3B are configured as one antigen testing element 3C that shares the space SP1 in which the sample 4 is sealed. One electrode 32A of the pair of electrodes 32A, 33A of the first testing element 3A and one electrode 32B of the pair of electrodes 32B, 33B of the second testing element 3B are configured as one common electrode 32C.

[0056] This has the advantage that the test is easier to perform because it eliminates the need to prepare an element for antigen testing that contains sample 4, compared to when the test is performed using elements in which the first test element 3A and the second test element 3B are separate from each other.

[0057] Furthermore, in the testing method according to the fourth aspect of the present disclosure, in any one of the first to third aspects, when the sample contains antigen 40, the amount of antigen 40 contained in the sample is further measured based on the difference between the current flowing through the first testing element 3A and the current flowing through the second testing element 3B.

[0058] This has the advantage that the amount of antigen 40 contained in the sample can be measured.

[0059] In the testing method according to the fifth aspect of the present disclosure, in any one of the first to fourth aspects, the antigen 40 is a virus.

[0060] This has the advantage that it is possible to test for the presence or absence of viruses that may be contained in the sample.

[0061] In addition, in the testing method according to the sixth aspect of the present disclosure, in the fifth aspect, the antigen 40 is SARS coronavirus 2.

[0062] This has the advantage of making it possible to test for the presence or absence of SARS-CoV-2, the cause of COVID-19, which may be present in the sample.

[0063] Moreover, an inspection system 100 according to a seventh aspect of the present disclosure includes a voltage application unit 1 and a measurement unit 2. The voltage application unit 1 applies a voltage that changes periodically and whose polarity is periodically reversed between the pair of electrodes 32A and 33A of the first inspection element 3A, which includes a sample 4 obtained by mixing a specimen with a solvent, a pair of electrodes 32A and 33A positioned to sandwich a space SP1 in which the sample 4 is sealed, and insulating layers 34A and 35A arranged on at least one of the sides sandwiching the space SP1, and between the pair of electrodes 32B and 33B of the second inspection element 3B, which includes the sample 4, a pair of electrodes 32B and 33B positioned to sandwich the space SP1 in which the sample 4 is sealed, and insulating layers 34B and 35B arranged on at least one of the sides sandwiching the space SP1. The measurement unit 2 compares the current flowing through the first testing element 3A when a voltage is applied with the current flowing through the second testing element 3B when a voltage is applied, thereby testing for the presence or absence of a charged antigen 40 in the specimen. The second testing element 3B is immobilized in a manner exposed to the sample 4 and includes an antibody 38 that specifically binds to the antigen 40, while the first testing element 3A does not include the antibody 38.

[0064] This has the advantage that it is possible to test for the presence or absence of antigen 40 that may be contained in the sample.

[0065] An antigen test element 3 according to an eighth aspect of the present disclosure includes a first test element 3A and a second test element 3B. The first test element 3A includes a sample 4 obtained by mixing a specimen with a solvent, a pair of electrodes 32A and 33A positioned to sandwich a space SP1 in which the sample 4 is sealed, and insulating layers 34A and 35A disposed on at least one side of the space SP1. The second test element 3B includes the sample 4, a pair of electrodes 32B and 33B positioned to sandwich the space SP1 in which the sample 4 is sealed, and insulating layers 34B and 35B disposed on at least one side of the space SP1. The second test element 3B includes an antibody 38 that is immobilized in a manner exposed to the sample 4 and specifically binds to a charged antigen 40 in the specimen, while the first test element 3A does not include the antibody 38.

[0066] This has the advantage that the antigen testing element 3 can be used to test for the presence or absence of antigen 40 that may be contained in a sample.

[0067] In addition, in the antigen test element 3 according to the ninth aspect of the present disclosure, in the eighth aspect, the first test element 3A and the second test element 3B are configured as one antigen test element 3C that shares the space SP1 in which the sample 4 is sealed. One electrode 32A of the pair of electrodes 32A, 33A of the first test element 3A and one electrode 32B of the pair of electrodes 32B, 33B of the second test element 3B are configured as one common electrode 32C.

[0068] This has the advantage that the test is easier to perform because it eliminates the need to prepare an element for antigen testing that contains sample 4, compared to when the test is performed using elements in which the first test element 3A and the second test element 3B are separate from each other. [Industrial Applicability]

[0069] The present disclosure can be applied to, for example, a method and system for testing the presence or absence of an antigen that may be contained in a sample. [Explanation of symbols]

[0070] 1. Voltage application section 2 Measuring section 2A 1st measurement section 2B 2nd measurement section 21, 21A, 21B IV Converter 22, 22A, 22B voltmeter 3. 3C antigen test element 3A First test element 3B Second testing element 31, 31A, 31B sealing material 32, 32A, 32B, 33, 33A, 33B electrode 32C common electrode 34, 34A, 34B, 34C, 35, 35A, 35B Insulation layer 36, 36A, 36B, 37, 37A, 37B Glass substrate 38 Antibodies 4. Sample 40 antigens 100, 100A Inspection System

Claims

1. a first testing element including a sample obtained by mixing a specimen with a solvent, a pair of electrodes positioned to sandwich a space in which the sample is sealed, and an insulating layer disposed on at least one of both sides of the space; a second testing element including the sample, a pair of electrodes positioned to sandwich a space in which the sample is sealed, and an insulating layer disposed on at least one of the two sides of the space; applying a voltage that periodically changes and periodically reverses polarity between the pair of electrodes; detecting the presence or absence of an antigen having a charge in the sample by comparing a current flowing through the first testing element due to the application of the voltage with a current flowing through the second testing element due to the application of the voltage; the second testing element is immobilized in a manner exposed to the sample and includes an antibody that specifically binds to the antigen, and the first testing element does not include the antibody; Testing method.

2. the step of applying the voltage between the pair of electrodes of the first testing element and the step of applying the voltage between the pair of electrodes of the second testing element are performed in parallel. The inspection method according to claim 1 .

3. the first test element and the second test element are configured as a single antigen test element that shares a space in which the sample is enclosed, one of the pair of electrodes of the first testing element and one of the pair of electrodes of the second testing element are configured as one common electrode; The inspection method according to claim 1 or 2.

4. When the specimen contains the antigen, the amount of the antigen contained in the specimen is further measured based on the difference between the current flowing through the first testing element and the current flowing through the second testing element. The inspection method according to claim 1 or 2.

5. The antigen is a virus. The inspection method according to claim 1 or 2.

6. The antigen is SARS coronavirus 2. The inspection method according to claim 5.

7. a first testing element including a sample obtained by mixing a specimen with a solvent, a pair of electrodes positioned to sandwich a space in which the sample is sealed, and an insulating layer disposed on at least one of both sides of the space; a voltage application unit that applies a voltage that periodically changes and periodically reverses polarity between the pair of electrodes of a second testing element, the second testing element including the sample, a pair of electrodes positioned to sandwich a space in which the sample is sealed, and an insulating layer disposed on at least one of both sides of the space; a measuring unit that tests for the presence or absence of an antigen having a charge in the sample by comparing a current that flows through the first testing element due to application of the voltage with a current that flows through the second testing element due to application of the voltage, the second testing element is immobilized in a manner exposed to the sample and includes an antibody that specifically binds to the antigen, and the first testing element does not include the antibody; Inspection system.

8. a first testing element including a sample obtained by mixing a specimen with a solvent, a pair of electrodes positioned to sandwich a space in which the sample is sealed, and an insulating layer disposed on at least one of both sides sandwiching the space; a second testing element including the sample, a pair of electrodes positioned to sandwich a space in which the sample is sealed, and an insulating layer disposed on at least one of both sides sandwiching the space; the second testing element is immobilized in a manner exposed to the sample and includes an antibody that specifically binds to an antigen having a charge in the specimen, and the first testing element does not include the antibody; Antigen testing element.

9. the first test element and the second test element are configured as a single antigen test element that shares a space in which the sample is enclosed, one of the pair of electrodes of the first testing element and one of the pair of electrodes of the second testing element are configured as one common electrode; The antigen testing element according to claim 8.

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