Immunodetection reagent card
By integrating traditional immunochromatography with microfluidic technology, and employing a non-stacked card design and direct antibody printing, the problems of complex structure and high cost in traditional technologies are solved, achieving efficient and low-cost immunoassay.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SOUTHWEST MEDICAL UNIV
- Filing Date
- 2025-04-23
- Publication Date
- 2026-05-08
AI Technical Summary
Traditional immunochromatography techniques are complex and have low production yields. Microfluidic technology is difficult and costly to produce, and the antigen/antibody coating process has poor stability and is difficult to control permeability.
This technology integrates traditional immunochromatography with microfluidics, employing a non-stacked card design. It utilizes a combination of a cover plate and a base plate to form a closed fluid pathway, allowing antibodies to be printed directly onto the microchannel. Combined with a cross-microarray and absorbent pad structure, it optimizes sample solution flow and pressure balance.
It simplifies the production process, reduces costs, improves production efficiency and detection sensitivity, avoids interference from residual liquids, and achieves highly efficient immunoassay.
Smart Images
Figure CN224216706U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an in vitro immunoassay technology, and more particularly to an immunoassay reagent card. Background Technology
[0002] Immunoassay technology relies on the specific binding principle of antigens and antibodies, combined with diverse reagent card structures, such as immunochromatography and immunomicrofluidics, to achieve testing objectives. However, the reagent card structure design of traditional immunochromatography is relatively complex, requiring at least four raw materials stacked in multiple layers. Its immunobinding efficiency is easily affected by the layout of various parts of the reagent card and the manufacturing process. In contrast, while immunomicrofluidics simplifies the reagent card structure stacking, it requires the design of multiple microfunctional structural regions, placing higher demands on the injection molding process and resulting in a lower production yield, thus hindering its widespread clinical application. Furthermore, the high production cost also limits its market acceptance. Therefore, integrating traditional chromatography technology with microfluidics to develop a more efficient chip has promising application prospects. Utility Model Content
[0003] To address the problems of traditional chromatography techniques being highly dependent on multilayer membrane structures and having complex processes; microfluidic technology being difficult to produce, costly, and difficult to popularize; and the poor stability of antigen / antibody coating processes and the difficulty in controlling permeability, this invention provides an immunoassay reagent card.
[0004] The technical solution adopted by this utility model to solve its technical problem is as follows: an immunoassay reagent card, including a shell and a liquid channel located inside the shell, the shell being formed by a bottom plate and a cover plate, the cover plate being provided with a sample application hole and an observation window, and also including a filter pad for guiding and filtering sample solution from the sample application hole to the liquid channel; the liquid channel is at least one microchannel through which the sample solution passes, and the microchannel is provided with a cross-shaped microarray arranged according to the capillary force principle to drive the sample solution to flow in the microchannel; a first labeling region, a second labeling region, and a third labeling region are sequentially arranged in the microchannel along the flow direction of the sample solution, and a labeling antibody, a capture antibody 1, and a capture antibody 2 are sequentially coated in the above-mentioned regions respectively; the observation window can observe at least the second labeling region and the third labeling region.
[0005] This invention directly coats labeled and captured antibodies onto microchannels using methods commonly found in the field, such as printing. This avoids the problem of uncontrollable permeability caused by printing functional antibodies on gold pads and NC membranes in existing technologies, significantly improving production efficiency while reducing process complexity.
[0006] As a further improvement of this invention, an absorbent pad is provided at the end of the microchannel to absorb the sample solution that has passed through the microchannel. This design utilizes the absorbent pad to absorb any residual sample solution after it has passed through the microchannel, thus preventing residual liquid from interfering with the detection results.
[0007] As a further improvement of this utility model, the cover plate is provided with a first air hole that connects to the filter pad and a second air hole that connects to the liquid absorption pad. The air hole arrangement of this solution can better achieve the air pressure balance inside the microchannel and optimize the flow of sample solution in the microchannel.
[0008] The microchannels of this invention can be formed by pre-setting microchannel grooves on a base plate, and then sealing the top of the microchannel grooves with an ultrasonic bond between the base plate and the cover plate, thereby forming the microchannels. Alternatively, other methods, such as pre-installing complete and independent microchannels, can also be used, as long as the microchannel setup can be completed. To ensure smooth sample flow and a suitable flow rate, and to facilitate subsequent observation, the width of the microchannels is preferably 20–40 mm, and the height is preferably 30–50 μm.
[0009] As is easily understood, the cross-microarray in this novel application utilizes the property of liquids spontaneously flowing forward under capillary force. This approach, combined with hydrophilic treatment, can further enhance the self-driven crawling ability of the liquid. The cross-microarray can be an array of microcylinders with their axes perpendicular to the flow direction of the sample solution within the microchannel. As a preferred approach, the diameter of a single microcylinder in the array is 60–100 μm, the spacing between adjacent microcylinders is 100–200 μm, and the height of the microcylinder is less than the height of the microchannel.
[0010] Because of the aforementioned microchannel structure, the observation window in this invention is preferably made of a transparent material. This ensures light transmittance for easy detection (such as reading fluorescence signals) while avoiding the risk of liquid leakage caused by traditional perforated designs. Materials such as PMMA and PS can be used. Ideally, the observation window should be integrated with the entire cover plate using a transparent material to simplify the manufacturing process. The rest of the cover plate, except for the observation window, can be covered with a light-blocking label.
[0011] The beneficial effects of this invention are: 1) The non-layered card design of this invention integrates traditional immunochromatography technology with microfluidic technology, abandoning the traditional multilayer membrane stacking structure (such as gold-labeled pads, NC membranes, etc.). A closed fluid pathway is formed by combining a cover plate and a base plate, simplifying the overall chip structure and reducing production complexity and cost. 2) This invention abandons traditional gold-labeled pads and NC membranes, directly coating the antibody onto the microchannel labeling region, improving process controllability and detection sensitivity. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the structure of the immunoassay reagent card in a specific implementation.
[0013] Figure 2 This is a top view of the cover plate in a specific embodiment.
[0014] Figure 3 This is a bottom view of the cover plate in a specific embodiment.
[0015] Figure 4 This is a top view of the base plate of the specific implementation method.
[0016] Figure 5 yes Figure 4 Enlarged view of region a.
[0017] Figure 6 This is a magnified view (top view) of the microchannel in a specific implementation.
[0018] Figure 7 This is a magnified view (side view) of the microchannel in a specific implementation.
[0019] The markings in the diagram are as follows: 1-base plate, 2-cover plate, 201-sample application port, 202-observation window, 203-first vent, 204-second vent, 205-filter pad fixing groove, 206-absorption pad fixing groove, 3-filter pad, 4-microchannel, 401-first marking area, 402-second marking area, 403-third marking area, 404-cross microarray, 4041-microcylinder, 5-absorption pad, 6-label. Detailed Implementation
[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0021] like Figures 1 to 7 As shown, the immunoassay reagent card of this utility model includes a shell and a liquid channel located inside the shell. The shell is formed by a base plate 1 and a cover plate 2. A light-shielding label 6 is affixed to the cover plate 2. The cover plate 2 is provided with a sample application hole 201 and a transparent observation window 202. It also includes a filter pad 3 (fixed in a filter pad fixing groove 205) for guiding and filtering the sample solution from the sample application hole 201 to the liquid channel. The liquid channel is a microchannel 4 through which the sample solution passes, and the microchannel 4 is provided with a cross microarray 404 for driving the sample solution to flow in the microchannel 4. A first labeling region 401, a second labeling region 402 and a third labeling region 403 are sequentially arranged in the microchannel 4 along the flow direction of the sample solution. Labeled antibodies, capture antibodies 1 and capture antibodies 2 are sequentially coated in the above regions. The observation window 202 allows observation of the second labeling region 402 and the third labeling region 403.
[0022] The end of the microchannel 4 is provided with an absorbent pad 5 (fixed in the absorbent pad fixing groove 206) for absorbing the sample solution passing through the microchannel 4. The cover plate 2 has a first air hole 203 that connects to the filter pad 3 and a second air hole 204 that connects to the absorbent pad 5.
[0023] The microchannel 4 is formed by pre-setting microchannel grooves on the base plate 1, and then sealing the top of the microchannel grooves with the base plate 1 and the cover plate 2 by ultrasonic bonding, thereby enclosing the microchannel grooves and the cover plate 2 to form the microchannel 4. The width W of the microchannel 4 is 40 mm, and the height h is 40 μm. The cross microarray 404 is an array of cylinders 4041 with their axial direction perpendicular to the flow direction of the sample solution in the microchannel 4. The diameter of each microcylinder 4041 in the cylinder array is 70 μm, the spacing between adjacent microcylinders 4041 is 140 μm, and the height of each microcylinder 4041 is 30 μm.
[0024] The testing process is as follows:
[0025] The processed sample solution is added to the well 201 using a pipette (e.g., a pipette). After impurities or large particles are removed by the filter pad 3, the sample flows into the microchannel 4. Due to the characteristics of the cross-array microarray 404 inside the microchannel 4, the sample solution spontaneously moves forward under capillary force. When the sample solution reaches the first labeled region 401 where the labeled antibody is located, a sample-labeled antibody complex is formed. As the complex continues to move along the microchannel, mixing continues. When the complex reaches the second labeled region 402 where the capture antibody 1 (T line) is located, a specific immune reaction occurs, generating a detection signal (e.g., a fluorescence signal) for quantitative or qualitative analysis of the target analyte. When the complex reaches the second labeled region 402 where the capture antibody 1 (T line) is located, it binds to the labeled antibody, verifying the effectiveness of the detection process. After the immune reaction is complete, specific fluorescence signals are emitted at the T line and C line, and the results can be read by a fluorescence detector. Excess liquid continues to flow to the absorbent pad 5 at the end of the microchannel 4, where it is completely absorbed by the adsorbent material, thus preventing residual liquid from interfering with the test results.
Claims
1. An immunoassay reagent card, comprising a housing and a liquid channel located inside the housing, the housing being formed by a base plate (1) and a cover plate (2), the cover plate (2) being provided with a sample application hole (201) and an observation window (202); further comprising a filter pad (3) for guiding and filtering sample solution from the sample application hole (201) to the liquid channel; characterized in that: The liquid channel is at least one microchannel (4) through which the sample solution passes, and the microchannel (4) is provided with a cross microarray (404) arranged according to the capillary force principle to drive the sample solution to flow in the microchannel (4); a first labeling region (401), a second labeling region (402) and a third labeling region (403) are arranged sequentially in the microchannel (4) along the flow direction of the sample solution, and the labeled antibody, capture antibody 1 and capture antibody 2 are respectively coated in the above regions; the observation window (202) can observe at least the second labeling region (402) and the third labeling region (403).
2. The immunoassay reagent card according to claim 1, characterized in that: The end of the microchannel (4) is provided with an absorbent pad (5) for absorbing the sample solution passing through the microchannel (4).
3. The immunoassay reagent card according to claim 2, characterized in that: The cover plate (2) has a first air hole (203) that connects to the filter pad (3) and a second air hole (204) that connects to the liquid absorption pad (5).
4. The immunoassay reagent card according to claim 1, characterized in that: The microchannel (4) is formed by first setting a microchannel groove on the base plate (1), and then sealing the top of the microchannel groove with the base plate (1) and the cover plate (2) by ultrasonic bonding, so that the microchannel groove and the cover plate (2) enclose the microchannel (4).
5. The immunoassay reagent card according to claim 1, characterized in that: The width of the microchannel (4) is 20-40 mm and the height is 30-50 μm.
6. The immunoassay reagent card according to claim 5, characterized in that: The cross microarray (404) is a cylindrical array in which the axis of the microcylinders (4041) is perpendicular to the flow direction of the sample solution in the microchannel (4). The diameter of a single microcylinder (4041) in the cylindrical array is 60-100 μm, the spacing between adjacent microcylinders (4041) is 100-200 μm, and the height of the microcylinder (4041) is less than the height of the microchannel (4).
7. The immunoassay reagent card according to any one of claims 1 to 6, characterized in that: The observation window (202) is made of transparent material.
8. The immunoassay test card according to any one of claims 1 to 6, characterized in that: It also includes a light-shielding label (6) covering the cover plate (2).