Folding lateral flow immunochromatography test paper card and preparation method thereof

Abstract

The invention discloses a foldable lateral flow immunochromatography test paper card and a preparation method thereof, and belongs to the technical field of immunodetection. The folding lateral flow immunochromatography test paper card provided by the invention is convenient and easy to carry and preserve, rapid detection can be realized, the detection time can be shortened on a large scale, meanwhile, the preparation method provided by the invention enables the reaction to be in a proper buffer condition by optimizing the components of the gold label pad, and the test paper treated by the method provided by the invention has the advantages that the test paper card is convenient to carry and preserve. The contact time of a sample and a conjugate is prolonged, so that the reaction is more sufficient, and the method is more suitable for on-site rapid detection and has an excellent application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of immunoassay detection, and in particular relates to a foldable lateral flow immunochromatography test paper card and a preparation method thereof. Background Art

[0002] Lateral flow immunoassay (LFIA) has been widely used due to its low cost, portability, reliability and ease of use. It has become an important and rapid diagnostic method in clinical, food safety, veterinary and environmental testing. There are currently two common lateral flow immunoassay test strips. One is to stick the sample pad, conjugate pad, NC membrane and absorbent paper on the PVC base plate in sequence. The other is to stick the sample pad, NC membrane and absorbent paper on the PVC base plate in sequence, and the conjugate is placed alone in a small tube or micro-reaction well. The reaction principle is that when the sample solution is dripped onto the sample pad, the liquid flows toward the absorbent paper driven by capillary action. During the flow process, the conjugate on the conjugate pad is first dissolved. The conjugate is usually colloidal gold, latex particles or fluorescent microspheres combined with labeled antibodies. The labeled antibody on the dissolved conjugate binds to the antigen in the sample. When it flows to the T line with the liquid, the antigen will bind to the capture antibody pre-coated on the T line, thereby forming a sandwich complex of capture antibody-antigen-conjugate. The T line will now show color or produce a fluorescent signal. The conjugates not captured by the T line will flow further with the liquid to the C line and be captured by the secondary antibody on the C line that can bind to the labeled antibody, thus making the C line also show color or produce fluorescence. Summary of the invention

[0003] In view of the above-mentioned prior art, the present invention provides a foldable lateral flow immunochromatography test paper card and a preparation method thereof, which can efficiently and accurately detect multiple targets simultaneously on a single test paper.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a foldable lateral flow immunochromatography test paper card, including a base plate, the base plate is divided into three pages, the first page is provided with a water absorbent pad, a gold label pad, a sample pad and a sample collection paper from top to bottom, the second page is provided with a nitrocellulose membrane, and the third page is provided with a sensitization pad; the lower part overlaps with the sample pad, and the upper part of the sample collection paper overlaps with the sample pad; a reaction line and a quality control line are provided on the nitrocellulose membrane.

[0005] Furthermore, the material of the bottom plate is waterproof cardboard.

[0006] The beneficial effects of the present invention are as follows: the foldable lateral flow immunochromatography test paper card provided by the present invention is convenient, easy to carry and easy to store, and integrates modules such as liquid sample collection, sample buffer system adjustment, sample detection, color development and sensitization into one device, which can facilitate rapid detection and greatly shorten the detection time, and provide an efficient use method for daily monitoring of ordinary people; at the same time, it has good scalability, and different functional modules can be integrated by adding folding pages up and down and left and right of the foldable lateral flow immunochromatography test paper card provided by the present invention, so as to achieve the purpose of controlling the reaction sequence by simple folding pages; and when the sample is dripped into the sample hole of the traditional detection card, the reaction time between the target in the sample and the gold-labeled antibody is fixed and determined by the liquid flow time, while the detection card can control the reaction time between the target and the gold-labeled antibody by folding and opening the paper base plane, and has the characteristics of rapid color development and control of reaction time; the foldable lateral flow immunochromatography test paper card is simple to manufacture, does not require mold opening, does not require professional instruments, has low cost, and can paste multiple gold-labeled pads on the first page, and the maximum number is determined by the width of the first page. The second page is for pasting one to multiple nitrocellulose membranes pre-coated with test lines and quality control lines. The types and quantities of these nitrocellulose membranes correspond to the gold label pads on the first page. This allows for the combination of multiple antibodies to detect multiple antigens. Different antibodies can be used to detect multiple substances, and different antibodies can be used to detect different antigens of the same substance, which increases the accuracy of the test and expands the application scenarios.

[0007] The present invention also provides a method for preparing a foldable lateral flow immunochromatography test paper card, comprising the following steps:

[0008] S1: The coated antigen or capture antibody and goat anti-mouse secondary antibody were drawn onto the reaction line and quality control line on the nitrocellulose membrane, and dried at 37°C for 12h;

[0009] S2: Mix a HAuCl4 aqueous solution with a concentration of 0.01 wv% and a trisodium citrate aqueous solution with a concentration of 1 wv% in a volume ratio of 100:3, boil, and keep boiling for 30 minutes to obtain a colloidal gold solution;

[0010] S3: The pH of the colloidal gold solution was adjusted to 7.33 and the antibody was added, mixed and allowed to stand for 30 minutes to obtain the gold-labeled antibody, and then 10% BSA solution was added and allowed to stand for another 30 minutes, and then centrifuged at 4°C, 12000rpm / min for 30 minutes, the precipitate was washed with PBS containing 1% BSA, centrifuged under the same conditions, and then the precipitate was redissolved in PBS solution to obtain the gold-labeled antibody solution;

[0011] S4: soak the glass cellulose membrane with the gold-labeled pad treatment solution for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain a pre-treated gold-labeled pad; add the gold-labeled antibody solution to the pre-treated gold-labeled pad, and dry it at 37°C for 12 hours to obtain a gold-labeled pad;

[0012] S5: Soak the glass cellulose membrane in the sample pad treatment solution for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain a sample pad;

[0013] S6: Soak the glass fiber membrane or filter paper in the sample collection paper treatment solution for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain the sample collection paper;

[0014] S7: Soak the polyester film or filter paper in a 0.01 wv% aqueous solution of HAuCl4 for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain a sensitization pad;

[0015] S8: Paste the absorbent pad, gold label pad, sample pad and sample collection paper on the first page of the base plate from top to bottom; paste the nitrocellulose membrane on the second page of the base plate, and ensure that after folding, the upper end of the nitrocellulose membrane and the absorbent pad overlap, and the lower end of the nitrocellulose membrane and the gold label pad overlap; paste the sensitization pad on the third page of the base plate.

[0016] The beneficial effects of the present invention are as follows: the design of the present invention makes the contact surface between the NC membrane and the gold-labeled pad and the absorbent paper more, and after the cover plate is covered, the contact surface is uniformly stressed, and the flow rate of the liquid on the NC membrane is also affected by the pore size of the membrane itself and the hydraulic pressure at both ends of the membrane, so that the pressure difference at both ends of the NC membrane of the present invention is greater than that of the traditional method, so the flow rate of the liquid on the membrane is fast, which can accelerate the color reaction; for some reactions, especially the competitive reaction of detecting small molecules, the target in the sample solution needs a certain reaction time to reach a reaction equilibrium with the gold-labeled antibody. In the traditional detection card, when the sample is dripped into the sample hole, the reaction time between the target in the sample and the gold-labeled antibody is fixed, which is determined by the liquid flow time, which often leads to insufficient reaction and reduced detection sensitivity. The foldable lateral flow immunochromatography test paper card of the present invention can overcome this problem. After absorbing the sample solution, it is left to stand for a period of time, and the target is fully reacted with the gold-labeled antibody, and then the first page is folded to the second page, so that the gold-labeled antibody is colored at the T and C line positions, so that the detection sensitivity can be improved.

[0017] Furthermore, in S3, the solid-liquid ratio of the gold-labeled antibody to the colloidal gold solution was 5 μg:1 mL, and the volume ratio of the 10% BSA solution to the mixed solution was 10:1.

[0018] Furthermore, the gold label pad treatment solution is a mixed solution of BSA, Tween-20 and mannitol, wherein the concentration of BSA is 0.01 g / mL, the concentration of Tween-20 is 2.5 μL / mL, and the concentration of mannitol is 0.001 g / mL.

[0019] Furthermore, the sample pad treatment solution was 20 mM PB containing 0.5% PVP K30, 0.1% hydroxylamine hydrochloride and 0.5% Tween-20.

[0020] Furthermore, the sample collection paper treatment solution is 20 mM PB containing 0.5% sodium heparin, 0.5% Tween-20 and 0.5% anti-human erythrocyte antibody or 20 mM PB containing 0.5% PVP K30 and 0.5% Tween-20.

[0021] The beneficial effects of the present invention are as follows: in traditional lateral flow immunochromatography, the reaction time between the target substance in the sample and the antibody on the conjugate is very short, which may lead to insufficient reaction. The foldable lateral flow immunochromatography test paper card provided by the present invention adopts a foldable structure, which can conveniently combine test papers for different targets on the first page, and each test paper can easily optimize the components of the gold label pad to make the reaction in a suitable buffer condition; the test paper treated by the method of the present invention prolongs the contact time between the sample and the conjugate, making the reaction more sufficient, and at the same time can protect the internal reagents from contamination, improve the sensitivity and accuracy of the antigen-antibody reaction, and simplify the operation steps, making it more suitable for on-site rapid detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A design diagram of a foldable lateral flow immunochromatography test paper card provided by the present invention;

[0023] Figure 2 This is the design drawing of the folding card box;

[0024] Figure 3 A diagram of the direction of liquid flow when the foldable lateral flow immunochromatographic test paper card provided by the present invention is in use;

[0025] Among them, 1 is a base plate, 2 is a water-absorbing pad, 3 is a sample pad, 4 is a gold-labeled pad, 5 is a sample collection paper, 6 is a nitrocellulose membrane, 7 is a sensitization pad, 8 is a base plate, 9 is a card slot, 10 is a buckle, and 11 is a cover plate. DETAILED DESCRIPTION

[0026] The specific implementation modes of the present invention are described in detail below with reference to the embodiments.

[0027] Example

[0028] This embodiment provides a foldable lateral flow immunochromatography test paper card and a method for preparing the test paper card.

[0029] 1. Main Materials

[0030] Coating antigen (capsaicin coating antigen, aflatoxin B1 coating antigen and zearalenone coating antigen were selected in this example), goat anti-mouse secondary antibody, nitrocellulose membrane, BSA (bovine serum albumin), and other reagents were all analytically pure reagents.

[0031] 2. A foldable lateral flow immunochromatographic test paper card, the structure of which is as follows Figure 1 As shown, the bottom layer is the base plate 1, which is made of hard waterproof material, such as waterproof cardboard; the base plate 1 is divided into three foldable pages, and the first page is provided with a water-absorbing pad 2, a plurality of gold label pads 4, a sample pad 3 and a sample collection paper 5 by pasting from top to bottom, wherein the lower part of the gold label pad 4 overlaps with the sample pad 3 (the overlapping part accounts for about 5 mm of the gold label pad 4), and the upper part of the sample collection paper 5 overlaps with the sample pad 3 (the overlapping part accounts for about 5 mm of the sample collection paper 5); the second page is provided with a plurality of nitrocellulose membranes 6 by pasting, and the nitrocellulose membranes 6 are provided with reaction lines and quality control lines; the third page is provided with a sensitization pad 7 by pasting.

[0032] The foldable lateral flow immunochromatographic test paper card of the present invention is prepared by the following steps:

[0033] S1: Use a gold-sprayed film streaker to streak 40 μL of capsaicin-coated antigen (0.5 mg / ml) and 40 μL (0.5 mg / ml) goat anti-mouse secondary antibody onto the T line and C line of the first nitrocellulose membrane 6 in the second page of the bottom plate 1, respectively, at a speed of 0.4 μL / cm; streak 40 μL of aflatoxin B1-coated antigen (0.4 mg / ml) and 40 μL (0.5 mg / ml) goat anti-mouse secondary antibody onto the T line and C line of the second nitrocellulose membrane 6 in the second page of the bottom plate, respectively; streak 40 μL of zearalenone-coated antigen (0.2 mg / ml) and 40 μL (0.5 mg / ml) goat anti-mouse secondary antibody onto the T line and C line of the third nitrocellulose membrane 6 in the second page of the bottom plate, respectively, and dry at 37°C for 12 h;

[0034] S2: Add 3 mL of 1 wv% sodium citrate trisodium aqueous solution to 100 mL of 0.01 wv% HAuCl4 aqueous solution, mix well and boil, keep boiling for 30 min to obtain a colloidal gold solution;

[0035] S3: 3 mL of colloidal gold solution was adjusted to pH 7.33 and then divided into 3 parts, capsaicin antibody (the material-liquid ratio of antibody to colloidal gold solution was 5 μg:1 mL), aflatoxin B1 antibody (the material-liquid ratio of antibody to colloidal gold solution was 4 μg:1 mL) or zearalenone antibody (the material-liquid ratio of antibody to colloidal gold solution was 5 μg:1 mL) was added respectively, mixed and allowed to stand for 30 min to obtain a mixed solution, and then a 10% BSA solution of one tenth of the volume of the mixed solution was added and allowed to stand for another 30 min, and then centrifuged at 4°C and 12000 rpm / min for 30 min, the precipitate was washed with PBS (phosphate buffer solution) containing 1% BSA, centrifuged under the same conditions, and then the precipitate was redissolved in the same volume of PBS solution to obtain capsaicin gold-labeled antibody solution, aflatoxin B1 gold-labeled antibody solution and zearalenone gold-labeled antibody solution, respectively;

[0036] S4: a mixed solution of BSA, Tween-20 and mannitol was prepared as a gold label pad treatment solution, wherein the concentration of BSA was 0.01 g / mL, the concentration of Tween-20 was 2.5 μL / mL, and the concentration of mannitol was 0.001 g / mL; the glass cellulose membrane was soaked in the gold label pad treatment solution for 1.5 hours, and then dried at 37°C for 24 hours to obtain a pre-treated gold label pad; 100 μL of capsaicin gold label antibody solution, aflatoxin B1 gold label antibody solution and zearalenone gold label antibody solution were added to three pre-treated gold label pads, respectively, and dried at 37°C for 12 hours to obtain gold label pad 4;

[0037] S5: Prepare 20 mM PB (phosphate buffer) containing 0.5% PVP K30 (polyvinyl pyrrolidone K30), 0.1% hydroxylamine hydrochloride and 0.5% Tween-20 (polyoxyethylene sorbitan monolaurate) as a sample pad treatment solution, soak the glass cellulose membrane with the sample pad treatment solution for 1.5 hours, and then dry it at 37°C for 24 hours to obtain sample pad 3;

[0038] S6: Prepare 20 mM PB (phosphate buffer) containing 0.5% PVP K30 (polyvinyl pyrrolidone K30) and 0.5% Tween-20 (polyoxyethylene sorbitan monolaurate) as a sample collection paper treatment solution, soak the glass cellulose membrane with the sample collection paper treatment solution for 1.5 hours, and then dry it at 37° C. for 24 hours to obtain sample collection paper 5;

[0039] S7: After soaking the polyester film in a 0.01% aqueous solution of HAuCl4 for 1.5 hours, the film was dried at 37°C for 24 hours to obtain a sensitizing pad 7;

[0040] S8: Paste the absorbent pad 2, the gold label pad 4, the sample pad 3 and the sample collection paper 5 on the first page of the base plate 1 from top to bottom, wherein one fifth of the gold label pad 4 overlaps with the sample pad 3, and one tenth of the sample collection paper 5 overlaps with the sample pad 3; paste the nitrocellulose membrane 6 on the second page of the base plate 1 to ensure that the nitrocellulose membrane 6 and the gold label pad 4 partially overlap after folding; paste the sensitization pad 7 on the third page of the base plate 1, and complete the assembly to obtain a foldable lateral flow immunochromatography test paper card.

[0041] In a preferred embodiment of the present invention, the sample collection paper treatment solution in step S6 is 20 mM PB containing 0.5% sodium heparin, 0.5% Tween-20 and 0.5% anti-human red blood cell antibody, and the other steps remain unchanged. This preferred embodiment can be used to detect blood samples.

[0042] 3. Use

[0043] The steps for use are as follows: first, unfold the three sides of the foldable lateral flow immunochromatography test paper card, then unfold the first page of sample collection paper 5 downward, drop the liquid sample to be tested on the sample collection paper 5, and use the strong water absorption of the sample collection paper 5 to absorb the liquid sample to the sample pad 3, and then fold the first page to the second page, and the liquid diffuses through the gold label pad 4 by capillary force. The dry gold label combines with the analyte in the sample after it meets water, and let it stand for 3 minutes to allow the analyte in the sample to fully react with the corresponding gold label antibody to complete the sampling. The present invention designs a folding card box, such as Figure 2 The card box shown includes a bottom plate 8, a card slot 9, a buckle 10 and a cover plate 11; after completing the above sampling, fold the first page toward the second page, fold the third page toward the first page, put it in the card slot 9 of the folding card box, buckle the buckle 10, close the cover plate 11 and react for 1 minute. During this process, under the capillary action, the combined gold particles-analyte react with the coated antigen and antibody at the corresponding position through the T line and the C line. Then open the cover plate 11, unfold the foldable lateral flow immunochromatography test paper card, observe the color development of the T line and the C line on the NC membrane, and make a result judgment. If red lines appear at both the T line and the C line, the content of the detection target corresponding to the test paper is lower than the detection limit, which is negative; if the T line does not show color, and only the C line position shows a red line, the content of the detection target exceeds the detection limit, which is positive. If the C line does not show color, the test paper is invalid.

[0044] In a preferred embodiment of the present invention, when performing sensitization detection on the color development result, after completing the above sampling, let it stand for reaction for 3 minutes, fold the third page toward the second page, then fold the first page toward the third page, put it in the card slot 9 of the folding card box, fasten the buckle 10, close the cover 11 and react for 1 minute, then open the cover 11, unfold the foldable lateral flow immunochromatography test paper card, first fold the third page toward the second page, then fold the first page toward the third page, put it in the card slot 9 of the folding card box, fasten the buckle 10, close the cover 11 and react for 3 minutes, then open the cover 11, observe the results on the nitrocellulose membrane 6, and draw a conclusion on whether the target analyte exists based on the results.

[0045] Experimental Example 1

[0046] Color development comparison experiment: A color development comparison experiment was conducted using the foldable lateral flow immunochromatographic test paper card prepared in the embodiment of the present invention and a traditional chromatographic test paper card. The experimental results are shown in the following table.

[0047] Table 1 Color contrast experimental results

[0048]

[0049]

[0050] It can be seen from the above results that compared with the traditional chromatography test paper card in which the sample pad, gold label pad, NC membrane, etc. are all on the same side, the foldable lateral flow immunochromatography test paper cartoon of the present invention has a multi-sided folding design, so that the overlapping length and contact area between the two ends of the NC membrane and the absorbent paper and the gold label pad are larger. In addition, the present invention also makes the contact surface evenly stressed by using a folding card box, and the liquid flow direction is as follows: Figure 3 As shown, the flow rate of the liquid on the NC membrane is affected by the pore size of the membrane itself and the hydraulic pressure at both ends of the membrane, making the pressure difference at both ends of the NC membrane larger than that of the traditional method. Therefore, the flow rate of the liquid on the membrane is fast, which can accelerate the color development reaction and reduce the color development time.

[0051] Experimental Example 2

[0052] Sensitization comparison experiment: The present invention uses the preferred scheme for sensitivity enhancement detection, and the traditional chromatographic test paper card is subjected to sensitivity enhancement detection through the following steps: first, the sample is dropped onto the traditional chromatographic test paper card, and the reaction is carried out for 15 minutes (to ensure that the colloidal gold on the gold pad completely flows through the NC membrane), 0.01wv% HAuCl4 solution and 0.1wv% hydroxylamine hydrochloride are mixed in a volume ratio of 1:1, 10μL of the mixed solution is dropped onto the NC membrane, and the reaction is carried out for 5 minutes, and the color development of the T and C lines is observed.

[0053] The present invention integrates all detection reagents into the detection card in the form of dry reagents, which is easier to store, transport and use. It does not require reagent premixing, mixing and pipetting equipment, is simple to operate, has a short detection time, and a color development time of 1 minute. The traditional chromatography test paper card has complicated operations for sensitization detection, and due to the absorption of the sensitization liquid by the absorbent paper and the gold label pad, the volume of the sensitization liquid reacted on the NC membrane is unstable, and the color development result is not as stable as that of the present invention. The color development time is 3 to 5 minutes, which is also longer than that of the present invention.

[0054] Although the specific implementation of the present invention is described in detail in conjunction with the embodiments, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A foldable lateral flow immunochromatography test paper card, characterized in that: The lateral flow immunochromatography test paper card comprises a bottom plate (1), wherein the bottom plate (1) is divided into three pages, wherein the first page is provided with a water absorbent pad (2), a gold label pad (4), a sample pad (3) and a sample collection paper (5) from top to bottom, the second page is provided with a nitrocellulose membrane (6), and the third page is provided with a sensitization pad (7); the lower part of the gold label pad (4) overlaps with the sample pad (3), and the upper part of the sample collection paper (5) overlaps with the sample pad (3); and the nitrocellulose membrane (6) is provided with a reaction line and a quality control line.

2. The foldable lateral flow immunochromatography test paper card according to claim 1, characterized in that: The base plate (1) is made of waterproof cardboard.

3. The method for preparing the foldable lateral flow immunochromatography test paper card according to claim 1 or 2, characterized in that: The following steps are involved: S1: The coating antigen and goat anti-mouse secondary antibody were drawn onto the reaction line and quality control line on the nitrocellulose membrane, respectively, and dried at 37°C for 12h; S2: Mix a HAuCl4 aqueous solution with a concentration of 0.01 wv% and a trisodium citrate aqueous solution with a concentration of 1 wv% in a volume ratio of 100:3, boil, and keep boiling for 30 minutes to obtain a colloidal gold solution; S3: The pH of the colloidal gold solution was adjusted to 7.33 and the antibody was added, mixed and allowed to stand for 30 minutes to obtain the gold-labeled antibody, and then a 10% BSA solution was added and allowed to stand for another 30 minutes, and then centrifuged at 4°C, 12000 rpm / min for 30 minutes, the precipitate was washed with PBS containing 1% BSA, centrifuged under the same conditions, and then the precipitate was redissolved in a PBS solution to obtain a gold-labeled antibody solution; S4: soak the glass cellulose membrane with the gold-labeled pad treatment solution for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain a pre-treated gold-labeled pad; add the gold-labeled antibody solution to the pre-treated gold-labeled pad, and dry it at 37°C for 12 hours to obtain a gold-labeled pad; S5: Soak the glass cellulose membrane in the sample pad treatment solution for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain a sample pad; S6: Soak the glass fiber membrane or filter paper in the sample collection paper treatment solution for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain the sample collection paper; S7: Soak the polyester film or filter paper in a 0.01 wv% aqueous solution of HAuCl4 for 1 to 2 hours, and then dry it at 37°C for 24 hours to obtain a sensitization pad; S8: Paste the absorbent pad, gold label pad, sample pad and sample collection paper on the first page of the base plate from top to bottom; paste the nitrocellulose membrane on the second page of the base plate, and ensure that after folding, the upper end of the nitrocellulose membrane and the absorbent pad overlap, and the lower end of the nitrocellulose membrane and the gold label pad overlap; paste the sensitization pad on the third page of the base plate.

4. The method for preparing the foldable lateral flow immunochromatography test paper card according to claim 3, characterized in that: The solid-liquid ratio of the gold-labeled antibody and the colloidal gold solution in S3 is 4-5 μg:1 mL, and the volume ratio of the 10% BSA solution and the mixed solution is 10:

1.

5. The method for preparing the foldable lateral flow immunochromatography test paper card according to claim 3, characterized in that: The gold label pad treatment solution is a mixed solution of BSA, Tween-20 and mannitol, wherein the concentration of BSA is 0.01 g / mL, the concentration of Tween-20 is 2.5 μL / mL, and the concentration of mannitol is 0.001 g / mL.

6. The method for preparing the foldable lateral flow immunochromatography test paper card according to claim 3, characterized in that: The sample pad treatment solution is 20 mM PB containing 0.5% PVP K30, 0.1% hydroxylamine hydrochloride and 0.5% Tween-20.

7. The method for preparing the foldable lateral flow immunochromatography test paper card according to claim 3, characterized in that: The sample collection paper treatment solution is 20 mM PB containing 0.5% sodium heparin, 0.5% Tween-20 and 0.5% anti-human erythrocyte antibody or 20 mM PB containing 0.5% PVP K30 and 0.5% Tween-20.

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