Detection device for detecting an analyte in a sample, detection plate, and method for forming an easily recognizable detection result

Abstract

The present invention relates to a detection device for detecting an analyte in a sample, including a sample detection layer provided with a detection line for indicating whether the analyte exists in the sample, and further including a symbol display layer provided with an indicating line containing an indicator. After the indicator contacts a gas that can cause it to change color, the indicator changes from a first color to a second color. The positions of the detection line and the indicating line are arranged in a certain shape, and the shape is used to indicate the situation of the analyte in the sample after the detection is completed. The device of the present invention can stably and clearly display the detection result, enabling an ordinary operator to more intuitively obtain the detection result, thereby making the population and scope of use of the detection device wider.

Description

[0001] This application is a divisional application of a patent application: the application number is 201710296044.7, and the application title is a divisional application of a detection device. Technical Field

[0002] The present invention relates to the field of detection, and particularly to a detection device for determining the presence of an analyte in a sample, a manufacturing method of the detection device, and a sample detection method for detecting a sample using the detection device. Background Art

[0003] Existing detection devices using the lateral flow method generally include a test strip, on which a sample application pad, a labeling pad, a detection pad, and a sample absorption pad are sequentially assembled. The detection pad includes a detection line and a control line. The detection line is used to determine whether an analyte exists in the sample. If a positive result is shown, it means that the analyte exists in the sample. If a negative result is shown, it means that the analyte does not exist in the sample. The quality control line is used to check and confirm whether the current detection process is successful.

[0004] In order to more intuitively show whether an analyte exists in the sample, there have been many products that make the positive result display at the detection line position in the form of “+” instead of the form of “-”. When the analyte exists, the detection result shows a “+” sign. When the analyte does not exist in the sample, the detection result shows a “-” sign. The display methods of “+” and “-” signs are more in line with the positive and negative result identifications that people are used to.

[0005] For example, in the patent of US7537937, another test piece is provided below the detection pad marked with the detection line, and the test piece has another color indicating line perpendicular to the detection line. During the test, the principle that the detection pad material becomes transparent after liquid chromatography is used to show the indicating line below it. When the analyte does not exist in the sample, the detection line on the detection pad does not appear, and the color indicating line on the test piece below the detection pad is shown through the transparent detection pad, and the whole detection result presents as a “-” symbol. When the analyte exists in the sample, a detection line will appear on the detection pad, and the color indicating line on the test piece below the detection pad is also shown through the transparent detection pad at the same time. The detection line and the color indicating line are displayed alternately, presenting as a “+” symbol. However, because the detection area material also has a certain transparency in the dry state, the indicating line can be faintly seen before the product test, which affects the appearance of the product.

[0006] In the patent of CN200510049177.1, the positive control area includes a water-absorbent strip made of a water-absorbent material, and the water-absorbent strip contains one or more substances that show a first color when dry and a second color when wet. Among them, the vertical indicator line of the "+" product is processed with water-sensitive ink on a layer of water-absorbent strip (absorbent paper), and then the absorbent paper is cut into the required line size and pasted under the detection area. During the test, on the one hand, the absorbent paper changes color, and on the other hand, the material in the detection area becomes transparent after liquid chromatography, so that the test results are presented as "+" and "-" respectively.

[0007] The main problem with this processing method is that the production process is relatively complex and requires multiple steps of assembly and processing to be produced. Summary of the Invention

[0008] Based on the above problems, the present invention provides a new detection device and a preparation method for the detection device to better achieve the detection and result display of the detection device.

[0009] Specifically, a detection device provided by the present invention includes a sample detection layer, a detection reagent for reacting with the analyte and a result display area are provided on the sample detection layer, and the device further includes a symbol display layer, and an indicator is processed on the symbol display layer; after the indicator contacts a gas that can cause it to change color, the indicator changes from a first color to a second color.

[0010] Preferably, when a sample is added to the sample detection layer for detection, a gas that causes the indicator to change color is generated and contacts the indicator to cause the indicator to change from a first color to a second color.

[0011] Preferably, the detection device further includes a gas generating agent, and the gas generating agent generates a gas that causes the indicator to change color.

[0012] Preferably, the indicator does not contact the result display area of the sample detection layer.

[0013] Preferably, a gas channel is provided between the sample detection layer and the symbol display layer.

[0014] Preferably, a gas channel is provided between the result display area on the sample detection layer and the indicator area on the symbol display layer.

[0015] Preferably, the result display area on the sample detection layer and the indicator area on the symbol display layer are in corresponding positions. Specifically, the position of the indicator and the position of the result display area are in a superimposed or overlapping relationship in space, that is, when looking vertically down from above the symbol display layer, the result display area and the indicator area are projected to overlap. More specifically, the indicator in the indicator area overlaps with the detection line in the result display area.

[0016] Preferably, the symbol display layer is located above the sample detection layer, and the symbol display layer is made of a transparent or translucent material that allows the detection result of the sample detection layer to be observed. When the indicator on the symbol display layer changes to a second color upon contact with a gas, it forms a recognizable symbol with the detection line on the sample detection layer.

[0017] Preferably, the recognizable symbol is a "+" or "-" symbol.

[0018] In some embodiments, the material of the symbol display layer is selected from water-impermeable materials or water-permeable materials. Preferably, the material of the symbol display layer is selected from water-impermeable materials.

[0019] In some embodiments, the material of the symbol display layer is selected from materials with poor air permeability or low air permeability. When the symbol display layer is made of a material with poor air permeability or low air permeability, the indicator can be added to the side of the symbol display layer that comes into contact with the gas, that is, the side adjacent to the sample detection layer (detection pad).

[0020] In other embodiments, the material of the symbol display layer is selected from breathable materials. When the symbol display layer is a breathable material, the indicator can be added to the side of the symbol display layer that comes into contact with the gas or the other side, or can be added in the middle of the symbol display layer, or in the middle of two stacked breathable symbol display layers. The gas contacts the indicator through the breathable material, causing the color of the indicator to change.

[0021] In some preferred embodiments, the material of the symbol display layer is selected from transparent air-impermeable materials such as PV, PP, films, etc. At this time, the indicator is treated on the side of the symbol display layer covering the sample detection layer. In other preferred embodiments, the material of the symbol display layer is selected from transparent breathable and water-impermeable materials such as breathable and water-impermeable membranes, PTFE membranes, etc. At this time, the indicator is treated on either side of the symbol display layer.

[0022] In a preferred embodiment, a liquid barrier layer is provided between the sample detection layer and the symbol display layer. The material of the liquid barrier layer is selected from transparent breathable and water-impermeable materials. With the liquid barrier layer, the indicator is separated from the detection layer, which is more conducive to fixing the indicator on the symbol display layer. The liquid barrier layer may or may not be in contact with the symbol display layer and the sample detection layer. For example, the liquid barrier layer is only in contact with the symbol display layer, or the liquid barrier layer is only in contact with the sample detection layer, or the liquid barrier layer is in contact with both the symbol display layer and the liquid detection layer or not in contact with either of them.

[0023] Preferably, the pairing combination of the indicator and the gas generator is selected from acid-base indicators and acid-base reaction reagents.

[0024] Preferably, the acid-base indicator is selected from bromothymol blue, bromocresol green, and phenolphthalein, and the acid-base reaction reagent is selected from an alkaline buffer salt or a combination of an ammonium salt and an alkaline buffer salt.

[0025] Preferably, the acid-base reaction reagent is disposed on the sample detection layer; the ammonium salt and the alkaline buffer salt are separately disposed on the sample detection layer, and the ammonium salt and the alkaline buffer salt do not contact before the sample is added to the sample detection layer.

[0026] Preferably, the sample detection layer includes a detection pad, and the result display area is located on the detection pad.

[0027] Preferably, the sample detection layer further includes a sample pad and a marking pad; the sample pad and the marking pad are sequentially connected upstream of the detection pad.

[0028] Preferably, the sample detection layer further includes a gas generating pad; the gas generating pad and the detection pad are located upstream of the detection pad.

[0029] Preferably, the gas generating pad is connected between the marking pad and the detection pad. Preferably, the symbol display layer covers the detection pad and the gas generating pad; there is a gas channel between the symbol display layer and the detection pad.

[0030] Preferably, the alkaline buffer salt and / or the ammonium salt are separately disposed on one or two of the sample pad, the marking pad, the gas generating pad, or the detection pad; when the ammonium salt and the alkaline buffer salt are disposed on the same pad, there is a certain distance between them.

[0031] In a specific embodiment, when the acid-base reaction reagent is selected from an alkaline buffer salt, the alkaline buffer salt is disposed on the sample pad, the marking pad, the gas generating pad, or the detection pad.

[0032] In another specific embodiment, when the acid-base reaction reagent is selected from a combination of an ammonium salt and an alkaline buffer salt, the ammonium salt and the alkaline buffer salt are respectively disposed on one or two of the sample pad, the marking pad, the gas generating pad, and the detection pad; when the ammonium salt and the alkaline buffer salt are disposed on the same pad, there is a certain distance between them, that is, they are located at different positions.

[0033] In a preferred embodiment, an ammonium salt is disposed on the gas generating pad.

[0034] More preferably, an alkaline buffer salt is disposed on the sample pad.

[0035] Preferably, an alkaline buffer salt and an ammonium salt are disposed on the gas generating pad, and the alkaline buffer salt and the ammonium salt are disposed at different positions on the gas generating pad, and there is a certain distance between them.

[0036] Preferably, the sample detection layer further includes a water absorption pad, which is connected downstream of the detection pad; one end of the symbol display layer covers the sample pad, and the other end covers the water absorption pad; there is no contact between the symbol display layer and the marking pad, the detection pad and the gas generation pad, forming a gas channel.

[0037] In some preferred embodiments, the detection device further includes a gas generation pad; the gas generation pad is in a perpendicular flow connection relationship with the detection pad, and the gas generation pad and the symbol display layer are arranged on two sides of the detection pad respectively.

[0038] Preferably, it further includes a sample pad, which is connected to the side of the gas generation pad that is not connected to the detection pad.

[0039] Preferably, both ends of one side of the detection pad have sticky blocks; the symbol display layer is connected to the detection pad through the sticky blocks; there is a gas channel between the symbol display layer and the detection pad.

[0040] In some vertical flow detection sample methods, when the sample is added to the detection layer, the sample preferably does not contact the symbol display layer, so it is necessary to open the symbol display layer to add the sample to the detection layer. Therefore, the movable connection, perhaps a separable connection, between the sample detection layer and the symbol display layer is to enable the symbol display layer to be separable from the sample detection layer. There are various structural ways of movable connection, such as tearable adhesion, snap connection, or plug-in connection, etc. The sample detection layer and the symbol display layer can be movably connected at one end and fixedly connected at the other end; or both ends can be movably connected.

[0041] In some embodiments, the alkaline buffer salt and / or ammonium salt are separately treated on one or two of the sample pad, the gas generation pad or the detection pad; when the ammonium salt and the alkaline buffer salt are treated on the same pad, there is a certain distance between them.

[0042] Preferably, the ammonium salt is treated on the gas generation pad. Preferably, the gas generation pad is also treated with an alkaline buffer salt, and the alkaline buffer salt and the ammonium salt are treated at different positions on the gas generation pad.

[0043] Preferably, the ammonium salt is treated on the sample pad. Preferably, the sample pad is also treated with an alkaline buffer salt, and the alkaline buffer salt and the ammonium salt are treated at different positions on the sample pad.

[0044] Preferably, the ammonium salt is treated on the gas generation pad and the alkaline buffer salt is treated on the sample pad.

[0045] Preferably, the material of the gas generation pad is selected from one of nitrocellulose, polyester film, glass fiber or filter paper.

[0046] In the present invention, a detection plate is further provided, which includes a bottom plate and a cover plate. A detection device is located between the bottom plate and the cover plate. The detection device includes a sample detection layer, and a result display area is provided on the sample detection layer. It is characterized in that it further includes a symbol display layer, and an indicator is disposed on the symbol display layer. The indicator does not contact the result display area of the sample detection layer. After the indicator contacts a gas that can cause it to change color, the indicator changes from a first color to a second color.

[0047] Preferably, the symbol display layer is located on the cover plate, and the sample detection layer is located on the bottom plate.

[0048] Preferably, the sample detection layer includes a detection pad, and the result display area is located on the detection pad.

[0049] Preferably, the sample detection layer further includes a sample pad, a marking pad, and a water absorption pad; the sample pad and the marking pad are sequentially connected upstream of the detection pad, and the water absorption pad is connected downstream of the detection pad.

[0050] Preferably, one or both of an ammonium salt and an alkaline buffer salt are disposed on the sample pad; the ammonium salt and the alkaline buffer salt are disposed at different positions on the sample pad.

[0051] Preferably, the sample detection layer further includes a gas generation pad; the gas generation pad is located between the marking pad and the detection pad.

[0052] Preferably, the ammonium salt is disposed on the gas generation pad, and the alkaline buffer salt is disposed on the sample pad.

[0053] Preferably, the cover plate of the detection plate has a window and a sample addition hole. The position of the window corresponds to the detection result area, and the sample addition hole is located at the sample pad.

[0054] In addition, the present invention further provides a sample detection method for visually reading a detection result, which includes a detection device. The detection device includes a sample detection layer and a symbol display layer; the symbol display layer is located on the sample detection layer; an indicator is disposed on the symbol display layer;

[0055] Let a fluid sample be applied and flow through the sample detection layer, and the sample detection layer performs sample detection to generate a detection line;

[0056] Meanwhile, the detection device generates a gas that causes the indicator to change color;

[0057] The gas contacts the indicator on the symbol display layer to cause the indicator to change from a first color to a second color;

[0058] The indicator of the second color is superimposed on the detection line to form a recognizable symbol.

[0059] Preferably, it further includes a gas generating agent, which reacts when a sample is applied to the detection device to generate a gas that causes the indicator to change color.

[0060] Preferably, all or part of the gas generating agent is disposed on the sample detection layer.

[0061] Preferably, the indicator is selected from bromothymol blue, bromocresol green, and phenolphthalein; the gas generating agent is selected from alkaline buffer salts, ammonium salts, and combinations of alkaline buffer salts.

[0062] Preferably, after applying the sample to the sample detection layer, an alkaline buffer salt is subsequently applied to the sample detection layer so that the alkaline buffer salt flows through the sample detection layer following the fluid sample.

[0063] Preferably, the sample detection layer includes a sample pad, a marking pad, a gas generating pad, and a detection pad connected in sequence; the ammonium salt is disposed on the gas generating pad; the sample flows through the sample pad, the marking pad, the gas generating pad, and the detection pad in sequence, gas is generated on the gas generating pad, and a detection line is generated on the detection pad.

[0064] On the other hand, the present invention also provides a method for manufacturing a detection device, including:

[0065] (1) Prepare a sample detection layer: provide a detection pad having a result display area, and add a detection reagent that reacts with the analyte to the detection pad;

[0066] (2) Prepare a symbol display layer: provide a transparent or semi-transparent carrier, prepare an indicator solution, and dispose the indicator solution on the carrier. After the indicator contacts the gas that can cause it to change color, it changes from the first color to the second color;

[0067] (3) Assemble the sample detection layer in step 1 and the symbol display layer in step 2 together, and make the indicator not contact the result display area of the sample detection layer;

[0068] (4) Provide a gas generating agent that can generate a gas that causes the indicator to change color.

[0069] Preferably, part or all of the gas generating agent is disposed on the detection layer.

[0070] Preferably, the sample detection layer includes a detection pad, a sample pad, and a marking pad. The sample pad, the marking pad, and the detection pad are connected to each other in sequence along the direction of liquid flow, and the gas generating agent is disposed on at least one of the sample pad, the marking pad, and the detection pad.

[0071] Preferably, it further includes a gas generating pad, and the gas generating pad is installed at any position before the detection pad, and the gas generating agent is added to the gas generating pad.

[0072] Preferably, the position and size of the indicator are set on the symbol display layer corresponding to the test line position of the result display area on the detection layer; the indicator is prepared into a solution with a certain concentration and uniformly coated on the symbol display layer according to the set position and size of the indicator.

[0073] Preferably, the indicator is selected from bromothymol blue, bromocresol green, phenolphthalein, and the gas generating agent is selected from alkaline buffer salts, ammonium salts, and combinations of alkaline buffer salts.

[0074] Preferably, the ammonium salt is selected from NH4Cl or ammonium carbonate, and the alkaline buffer solution is selected from Tris buffer solution.

[0075] Preferably, ammonium chloride or ammonium carbonate is prepared into a 1% solution and treated on the sample detection layer.

[0076] Preferably, the material of the gas generating pad is selected from one of glass fiber, filter paper or polyester film.

[0077] Preferably, the material of the symbol display layer is selected from transparent or semi-transparent water-impermeable materials.

[0078] Preferably, a liquid barrier layer is provided between the sample detection layer and the symbol display layer, and the material of the liquid barrier layer is selected from transparent breathable and water-impermeable materials.

[0079] The present invention also provides a method for visually reading a test result, including a detection device, which includes a sample detection layer and a symbol display layer; the symbol display layer is located on the sample detection layer; an indicator is treated on the symbol display layer; after the indicator contacts a gas that can cause it to change color, the indicator changes from a first color to a second color, forming a recognizable symbol with the test result on the sample detection layer.

[0080] Preferably, it further includes a gas generating agent, and the gas generating agent reacts when a sample is applied to the detection device to generate a gas that causes the indicator to change color.

[0081] Preferably, all or part of the gas generating agent is treated on the sample detection layer.

[0082] Preferably, the indicator is selected from bromothymol blue, bromocresol green, phenolphthalein; the gas generating agent is selected from alkaline buffer salts, ammonium salts, and combinations of alkaline buffer salts.

[0083] Preferably, the sample detection layer includes a sample pad, a marking pad, a gas generating pad, and a detection pad connected in sequence; the ammonium salt is treated on the gas generating pad; the sample flows through the sample pad, the marking pad, the gas generating pad, and the detection pad in sequence, gas is generated on the gas generating pad, and a test line is generated on the detection pad.

[0084] Beneficial effects

[0085] The device and the detection board of the present invention can display the detection results stably and clearly, so that ordinary operators can obtain the detection results more intuitively, thereby making the detection device more widely used by a wider range of people. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 is a schematic diagram of a detection device of the present invention;

[0087] Figure 2 is a schematic diagram of another detection device of the present invention;

[0088] Figure 3 is a schematic diagram of another detection device of the present invention;

[0089] Figure 4 is a schematic diagram of another detection device of the present invention;

[0090] Figure 5 is a schematic diagram of a specific detection device of the present invention;

[0091] Figure 6 yes Figure 5 Top view of the device (positive test result shown);

[0092] Figure 7 yes Figure 5 Another top view of the device (negative test result shown);

[0093] Figure 8 yes Figure 5 An exploded schematic diagram of the device;

[0094] Figure 9 is a schematic diagram of another specific detection device of the present invention;

[0095] Figure 10 yes Figure 9 An exploded schematic diagram of the device;

[0096] Figure 11 is a schematic diagram of another specific detection device of the present invention;

[0097] Figure 12 yes Figure 11 A front view of the detection device;

[0098] Figure 13 is a schematic diagram of another detection device of the present invention;

[0099] Figure 14 yes Figure 13 A cross-sectional view of the detection device;

[0100] Figure 15 yes Figure 13 An exploded schematic diagram of the detection device;

[0101] Figure 16 Schematic diagram of the superposed display of the result display area and the indicator area (positive test result display);

[0102] Figure 17 It is a schematic diagram of another detection device of the present invention;

[0103] Figure 18 It is a schematic diagram of the structure of the test board of the present invention;

[0104] Figure 19 is Figure 18 Exploded schematic diagram of the test board;

[0105] Figure 20 is Figure 18 Another exploded schematic diagram of the test board;

[0106] Reference numerals:

[0107] Detection device 10, sample detection layer 1, symbol display layer 2, indicator / indicator display symbol 21, liquid barrier layer / isolation pad 5, indicator area 23, (test) result display area 18, test pad 17, gas generating pad 16, marking pad 13, sample pad 12, water absorption pad 8, bottom card 11, test line 171, quality control line 172, adhesive block 3, test board 40, bottom plate 41, cover plate 42, window 43, sample addition hole 45, space / gas channel 22 Detailed implementation manners

[0108] The following further explains the structures involved in the present invention or the technical terms used therein.

[0109] Detection

[0110] "Detection" means assaying or testing for the presence of a substance or material, such as, but not limited to, chemical substances, organic compounds, inorganic compounds, metabolites, drugs or drug metabolites, organic tissues or metabolites of organic tissues, nucleic acids, proteins or polymers. Additionally, detection means testing the quantity of a substance or material. Further, assay also means immunoassay, chemical assay, enzyme assay, etc.

[0111] Type of sample

[0112] Any type of sample can be tested using the device of the present invention, including body fluids (e.g., urine and other body fluids, as well as clinical samples). Liquid samples may be derived from solid or semi-solid samples, including feces, biological tissues, and food samples. These solid and semi-solid samples can be converted into liquid samples by any suitable method, such as mixing in a suitable liquid, dicing, macerating, incubating, dissolving, or enzymatically digesting the solid sample (e.g., water, phosphate buffer, or other buffer). "Biological samples" include samples derived from living animals, plants, and food, as well as urine, saliva, blood and blood components, cerebrospinal fluid, vaginal swabs, semen, feces, sweat, secretions, tissues, organs, tumors, cultures of tissues and organs, cell cultures, and conditioned media therefrom, whether human or animal. Food samples include processed food ingredients and final products, meat, cheese, wine, milk, and drinking water. Plant samples include samples derived from any plant, plant tissue, plant cell culture, and conditioned media therefrom. "Environmental samples" are those samples derived from the environment (e.g., lake water samples or samples from other water bodies, sewage samples, soil samples, groundwater samples, seawater samples, samples of waste wastewater). Sewage and related wastes may also be included in environmental samples.

[0113] Type of analyte

[0114] Examples of analytes that can be stably detected using the present invention include (but are not limited to) human chorionic gonadotropin (hCG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), hepatitis C virus (HCV), hepatitis B virus (HBV), hepatitis B surface antigen, human immunodeficiency virus, and any abused drug. Analytes can be detected in any liquid or liquefied sample, such as urine, saliva, blood, plasma, or serum. Other examples of analytes include creatinine, bilirubin, nitrite, protein (nonspecific), blood, white blood cells, blood glucose, heavy metals, and toxins, bacterial components (e.g., specific proteins and sugars of specific types of bacteria, such as Escherichia coli O157:H7, Staphylococcus aureus, Salmonella, Clostridium perfringens, Campylobacter, Listeria monocytogenes, Vibrio parahaemolyticus, or Bacillus cereus). Any other analyte suitable for lateral flow test formats can be detected using this device. The present invention will be further described in detail below with reference to the accompanying drawings and examples, but the scope of protection of the present invention is not limited thereto.

[0115] The detection device 10 of the present invention includes two parts: a sample detection layer 1 and a symbol display layer 2; an indicator 21 capable of changing color is disposed on the symbol display layer 2; the detection device 10 is formed by the combination of these two parts, as Figure 1As shown. The detection device 10 is capable of forming a display of an easily recognizable detection result or detection information after sample detection. Specifically, the symbol display layer 2 forms a display symbol by changing the color of the indicator 21, and this display symbol can represent the detection information or detection result of the detection device 10. The shape of the indicator 21 disposed on the symbol display layer 2 can be set as needed. In this way, the symbol displayed after the color change is the same as the shape of the indicator, such as: numbers, 1, 0, etc.; simple graphics, -, ∣, ×, Δ, etc.; characters; letters, Y, N, etc.; The symbol shape can be set according to the needs of the detection device 10 by using the indicator to represent it.

[0116] In some preferred embodiments, the indicator on the symbol display layer 2 does not contact the sample detection layer 1. More specifically, the area 23 having the indicator on the symbol display layer 2 does not contact the sample detection layer 1, such as Figure 2 and Figure 3 in, the bottom surface of the symbol display layer 2 directly contacts and covers the sample detection layer 1. At this time, the indicator 21 is disposed on the upper surface of the symbol display layer 2 (i.e., the surface that does not contact the sample detection layer). In a specific embodiment, a gas channel is provided between the sample detection layer and the symbol display layer; or, in another specific embodiment, a gas channel is provided between the result display area on the sample detection layer and the indicator area on the symbol display layer, such as Figure 5 、 Figure 9 and Figure 11 shown. When the indicator 21 is disposed on the surface adjacent to the detection layer 1, there is a gap or space 22 between the symbol display layer 2 and the sample detection layer 1 of the detection device 10, so that the indicator area 23 does not contact the detection layer 1, and the gap or space 22 is a gas channel 22 for gas volatilization.

[0117] The positions of the sample detection layer 1 and the symbol display layer 2 on the detection device 10 can be such that the symbol display layer 2 covers part or all of the sample detection layer 1. As Figure 2 shown, the symbol display layer 2 covers part of the sample detection layer 1; as Figure 3 , the symbol display layer 2 covers all of the sample detection layer 1. Or the sample detection layer 1 and the symbol display layer 2 are at different positions on the detection device 10, that is, they do not cover each other on the vertical projection plane.

[0118] After the indicator comes into contact with the gas that causes its color change, its color changes from the first color to the second color, and the symbol shown by the second color can be used to indicate what kind of detection item the detection device 10 in use is. For example, on the detection device for drug abuse detection, the shapes of the indicators on the symbol display layer are different. For the detection device for detecting morphine use, the shape of the indicator on its symbol display layer is MOP (the English abbreviation of morphine). For the detection device for detecting cocaine use, the shape of the indicator on its symbol display layer is COC (the English abbreviation of cocaine). For example, in an embodiment, after adding a sample to the detection layer, a gas is generated due to the liquid sample itself or the trigger of the sample, causing the indicator to display the symbol COC, indicating that the detection item of the detection device is cocaine.

[0119] The symbol shown by the second color after the color change of the indicator can also cooperate with the detection line on the sample detection layer to form an identifiable symbol that is easily understood by the user. In some specific embodiments, such as Figure 2 and Figure 3 , the sample detection layer 1 includes a result display area 18, and the indicator area 23 of the symbol display layer 2 corresponds to the position of the result display area 18 on the sample detection layer. That is, the position of the indicator area 23 and the position of the result display area 18 are in a superposed or overlapping relationship in space. Thus, the color symbol formed by the indicator 21 can be superposed with the detection line 171 on the sample detection layer 1, that is, the color symbol of the indicator and the detection line form a new symbol after being vertically projected onto a plane, such as Figure 6 and Figure 7 and Figure 16 shown, forming one or more result displays that are easy to understand and identify. Figure 6 , after adding the sample and when the analyte exists in the sample or the content of the analyte reaches a preset test value, a detection line 171 appears on the sample detection layer, forming a "+" symbol with the colored indicator 21; Figure 7, after adding the sample and when there is no analyte in the sample or the content of the analyte does not reach the pre-set test value, no test line 171 appears in the result display area of the sample detection layer, and the separate colored indicator 21 presents a "-" symbol. Such a symbol indication conforms to people's result interpretation habits in positive and negative detections. People are used to using "+" to represent positive and "-" to represent negative. In the detection of ordinary lateral flow test strips, the test result display usually shows one test line or no test line. In the judgment of ordinary operators, errors may occur due to unfamiliarity. In the present invention, the "+" or "-" symbol can be formed by the superposition of the color symbol of the indicator and the test line. Of course, the superposed test result display conformities can also be diverse. For example, the indicator shows "Ο", and combined with the test result to form display conformities such as "Φ", "Θ" or "Ο" to show positive and negative or opposite test results such as positive and negative or front and back.

[0120] The indicator 21 of the symbol display layer shows the symbol by changing color, which can be changed from one color to another color, so that the operator can obtain the detection information through the change of color. For example, from colorless to red, from light color to dark color, from red to green, blue, etc.; or, from red to colorless, from dark color to light color, etc. Specifically, usually, in a detection device where the test line presents a recognizable color after the detection is over to represent a positive result, in order to prevent the operator from misinterpreting the information, the indicator usually changes from colorless to an easily observable color, or the first color of the indicator is the same as or similar to the background color of the test pad 17, and changes to the second color after the detection. The indicator 21 adopts a colorless or a color close to the background color of the test pad that is not easily noticed by the user before the detection starts. Compared with the first color of the indicator being an easily noticed color, it can also prevent the user from mistakenly thinking that the actually unused detection device has been used. In a detection device where the test line presents a recognizable color after the detection is over to represent a negative result, the indicator can also be changed from an easily observable color to colorless, or the second color of the indicator is the same as or similar to the background color of the test pad.

[0121] The change of color is achieved by the reaction of the indicator with the gas in contact. There are many types of such color-changing reactions, such as acid-base indicator reactions.

[0122] The indicator is selected from acid-base indicators, such as nitro-phenol-based, phenolphthalein-based, sulfonated phenolphthalein-based, azo compound-based acid-base indicators; specifically, p-nitrophenol, phenolphthalein, thymolphthalein, α-naphtholphthalein, phenol red, cresol red, bromophenol blue, thymol blue, methyl orange, neutral red, etc. More specifically, for example, methyl orange, methyl red, etc. that are orange in acidic environment and yellow in alkaline environment, bromothymol blue that is yellow in acidic environment and blue in alkaline environment, phenolphthalein that is colorless in acidic environment and red in alkaline environment, litmus that is red in acidic environment and blue in alkaline environment are selected. Different acid-base indicators can produce color changes when encountering acidic or alkaline gases for the supporting reactions.

[0123] The gas that triggers the color change of the indicator 21 is generated by a gas generator. Specifically, gases can be generated by mixing different substances, or by mixing different substances with a liquid sample. These different substances do not mix with each other when the detection device 10 is not in use, at least not all substances are mixed together, so as to avoid premature generation and release of gases, resulting in the gas being unable to contact the indicator 21 on the detection device. For example, in the scheme of using ammonia to contact the bromophenol blue indicator to change the indicator from light yellow to blue, the substances that generate ammonia include ammonium chloride and an alkaline buffer salt. Ammonium chloride and the alkaline buffer salt are added to different positions on the detection pad and do not contact each other; or ammonium chloride and the alkaline buffer salt are separately added to different pads among the sample pad 12, the marking pad 13, and the detection pad 17; or, if the detection device 10 includes a gas generation pad, one of the reagents of ammonium chloride or the alkaline buffer salt is added to the gas generation pad 16, and the other reagent is added to other positions where the liquid flows through, such as one or more pads among the sample pad 12, the marking pad 13, or the detection pad 17. Or when one of the reagents of ammonium chloride and the alkaline buffer salt is prepared as a solution for use, the other reaction reagent is added to one or more pads among the sample pad 12, the marking pad 13, the gas generation pad 16, or the detection pad 17, and the solution reagent is added during detection to mix ammonium chloride and the alkaline buffer salt to generate gas. Or both ammonium chloride and the alkaline buffer salt are prepared as solutions, and the two solutions are added to the detection device during detection to mix and generate ammonia.

[0124] The generated gas can also combine with the water vapor in the test space to cause the indicator reaction to change color.

[0125] In some specific embodiments, ammonia is generated by the decomposition of ammonium salts in an alkaline environment to change the color of the acid-base indicator 21 on the symbol display layer 2. More specifically, for some samples that inherently contain ammonium salts, such as urine samples, when the sample is added to the detection device for testing, the ammonium salts in the sample react with the alkaline buffer salts to decompose and generate ammonia, causing the acid-base indicator to change from the first color to the second color, displaying the indicator symbol, or the indicator symbol is superimposed on the test result line to form a result display symbol. In some other embodiments, the ammonium salts can be pre-treated on the detection layer 1, and when the sample is added, the alkaline buffer salts are added, so that the ammonium salts decompose and release ammonia in the alkaline environment, causing the indicator 21 to change color. In some preferred embodiments, the sample inherently contains ammonium salts. When the sample is added to the detection layer 1, the sample is in an alkaline environment, generating ammonia, causing the indicator 21 to change from the first color to the second color. In some embodiments, the alkaline buffer salts are selected from borax, Na2CO3, K3PO4, etc.

[0126] In more specific embodiments, Figure 4 As shown, a liquid barrier layer 5 can be added between the sample detection layer 1 and the symbol display layer 2 of the detection device 10. The function of the liquid barrier layer 5 is to be breathable but not permeable to water. And the liquid barrier layer 5 is transparent. When the liquid sample is added to the detection layer, the substance to be detected in the sample reacts with the pre-treated substance on the detection layer 1 to form a distinct line - the test line. At the same time, when the sample flows through the detection layer 1, the released gas passes through the liquid barrier layer 5, causing the indicator 21 disposed on the symbol display layer 2 to change color to form a second color line. The line generated by the reaction of the substance to be detected and the indicator line form a "+" or "-".

[0127] The material of the symbol display layer 2 can generally be selected as a transparent or semi-transparent material to facilitate observing the covered test result area. The material of the symbol display layer 2 can be selected as a water-impermeable material, and the material of the symbol display layer 2 can be selected as a breathable or non-breathable material; for example, PTFE film, breathable and water-impermeable film, PET, PE, PP, etc. When the material of the symbol display layer 2 is a non-breathable material, the indicator 21 is located on the side of the symbol display layer 2 adjacent to the sample detection layer. When the material of the symbol display layer 2 is a breathable material, the indicator 21 can be located on the side of the symbol display layer 2 adjacent to the sample detection layer or on the side away from the sample detection layer, that is to say, the indicator 21 can be located on the front or back of the symbol display layer. Of course, when there is a liquid barrier layer 5 between the symbol display layer 2 and the sample detection layer 1, the material of the symbol display layer 2 can be selected as a water-permeable material.

[0128] In some embodiments, the sample detection layer 1 includes a detection pad 17, and a detection result display area 18 is provided on the detection pad 17. Moreover, the symbol display layer 2 covers the detection pad 17, such that the indicator area 23 corresponds to the detection result display area 18, that is, the two are in an overlapping or superposed position spatially. Figure 5 As shown, in this way, the indicator 21 and the detection result 171 can be superposed to form a recognizable symbol, such as Figure 6 and Figure 7 as shown.

[0129] Similarly, as Figure 5 shown, in some embodiments, the sample detection layer 1 further includes a gas generation pad 16, and the gas generation pad 16 is used for generating gas. Therefore, an ammonium salt is disposed on the gas generation pad 16. After the sample flows through the gas generation pad 16, the ammonium salt decomposes in an alkaline environment to generate ammonia gas to change the color of the indicator 21.

[0130] In a more specific embodiment, the sample detection layer 1 further includes a marking pad 13 and a sample pad 12. The sample pad 12 and the marking pad 13 are sequentially connected upstream of the gas generation pad 16, and the gas generation pad 16 is connected upstream of the detection pad 17, that is, the sample sequentially flows through the sample pad 12, the marking pad 13, the gas generation pad 16, and the detection pad 17. In another embodiment, the detection layer 1 further includes a water absorption pad 8 connected downstream of the detection pad 17 and a bottom card 11 for fixing the sample pad 12, the marking pad 13, the gas generation pad 16, the detection pad 17, and the water absorption pad 8. At this time, an alkaline buffer salt can be disposed on the sample pad 12. After the sample is added to the sample pad 12, it drives the alkaline buffer salt to flow and reach the gas generation pad 16, such that the ammonium salt on the gas generation pad 16 decomposes in an alkaline environment to generate ammonia gas.

[0131] In some other embodiments, as long as the gas generated by triggering through the gas generation pad 16 can contact the indicator 21 on the symbol display layer 2, the storage position of the gas generation pad 16 on the detection device 10 can be arbitrarily selected.

[0132] In some embodiments, one end of the symbol display layer 2 is connected to the sample pad 12, and the other end is connected to the water absorption pad 8, such that a space is formed between the symbol display layer 2 and the marking pad 13, the gas generation pad 16, and the detection pad 17. This space is a gas channel, which is more conducive to the diffusion of gas. This space can be open or closed.

[0133] In some embodiments, the symbol display layer 2 and the sample detection layer 1 can be fixedly connected, or can be movably connected or detachably connected. For example, the symbol display layer 2 and the sample detection layer 1 are directly bonded and fixed; or the sample detection layer 1 is fixed on a bottom plate, and the symbol display layer 2 is fixed on a cover body. When the cover body is covered with the bottom, the symbol display layer 2 covers the sample detection layer 1. Figure 20As shown. Alternatively, the end of the symbol display layer 2 is fixed to the sample detection layer 1 by a tearable adhesive strip, Figure 11 and so on. In some more preferred embodiments, a certain space 22 is formed between the symbol display layer 2 and the sample detection layer 1, so that there is a certain distance between the indicator area 23 of the symbol display layer and the detection layer 1, such as Figure 5 shown.

[0134] In some specific embodiments, such as Figure 11 shown, a protrusion 3 is provided at the end of the sample detection layer of the detection device, and the end of the symbol display layer is connected to the protrusion 3, so that the symbol display layer 2 and the sample detection layer 1 are covered and connected to each other, and a space 22 is formed therebetween. Among them, the positions of the indicator area and the result display area are superimposed and corresponding, such as Figure 11 and 16 shown.

[0135] Next, the detection device of the present invention will be described with some specific embodiments.

[0136] Embodiment 1: Figure 5 , Figure 6 , Figure 7 and Figure 8 The detection device described

[0137] such as Figure 5 shown, the lateral flow detection device 10 for detecting hCG in urine includes a detection layer 1 and a symbol display layer 2. The symbol display layer 2 covers the detection layer 1, and a certain space is reserved between the two as a gas volatilization channel 22. Specifically, the detection layer 1 includes a bottom card 11, on which a sample pad 12, a labeling pad 13, a gas generating pad 16, a detection pad 17, and a water absorption pad 8 are sequentially and mutually overlapped and pasted, such as Figure 5 shown. One end of the symbol display layer 2 overlaps on the sample pad 12, and the other end overlaps on the water absorption pad 8, so that a space 22 is formed between the symbol display layer 2 and the labeling pad, the gas generating pad, and the detection pad. The sample pad 12 is used to receive the detection sample and transfer the sample to the functional pads (such as the labeling pad, the detection pad, etc.) downstream thereof. In this embodiment, the labeling pad 13 is coated with a colloidal gold-labeled anti-hCG antibody (labeling antibody), and the labeling antibody binds to the hCG antigen in the sample to form a first conjugate. At least a detection line 171 is provided on the detection pad 17. In this embodiment, the detection line 171 is coated with an hCG antibody, and the first conjugate flowing to the detection pad binds to the anti-hCG antibody on the detection line to form a visible line to the naked eye. If the hCG content in the urine is lower than the lowest threshold for detection, no visible line will be formed on the detection line. A quality control line 172 may also be included on the detection pad 17, and the quality control line 172 is used to indicate whether the current detection is successfully completed.

[0138] Prepare solutions with different types of indicators shown in Table 1 at a certain concentration. Then, process the prepared indicator solutions on different transparent plastic sheets respectively to form the indication lines 21 (the transparent plastic sheets in this example are the symbol display layers 2 described in the present invention). Assemble the side of the transparent sheet with the indicator adjacent to the sample detection layer and the sample detection layer together, with the indication line directly above the detection line, forming a cross.

[0139] In a specific embodiment, the width of the sample detection layer is 7.2 mm, the width of the corresponding transparent sheet (symbol display layer) covering the sample detection layer is 7.2 mm, the width of the indicator is 1 mm, and the length is 8 mm.

[0140] In this embodiment, prepare an aqueous solution of 1% of an ammonium salt, such as ammonium chloride or ammonium carbonate, etc., and process it on the gas generation pad 16 by soaking or other means. The sample pad 12 is treated with an alkaline buffer salt. For example, the alkaline buffer salt is 100 mM Tris buffer solution, pH 8.0. After soaking the sample pad in this buffer solution, a sample pad with an alkaline buffer solution is obtained. The soaked gas generation pad and sample pad are assembled into the detection device in a dry state. During the test, after the sample is mixed with the alkaline buffer salt of the sample pad, the pH of the sample increases. When the ammonium salt in the gas generation pad contacts the alkaline sample, the ammonium salt decomposes to generate ammonia gas and is released. The sample brings gaseous ammonia during the chromatography process and contacts the indicator on the transparent plastic sheet, causing the indicator to change color.

[0141] When the hCG content in the sample is higher than the lowest detection value, a visible color line will be formed on the detection line 171 of the detection pad. This color line and the indication line on the symbol display layer 2 form a "+" symbol spatially. The tester can judge that the sample is positive based on the appearance of the "+", as Figure 6 shown. If the hCG content in the urine is lower than the lowest detection value, a colored line will not be formed on the detection line of the detection pad, and only a visible indication line will appear on the detection line of the symbol display layer, thus forming a "-" symbol, as Figure 7 shown. The tester judges that the sample is negative based on the "-".

[0142] Detect using a urine standard product containing 100 mIU / ml hCG. Record the color of the indication line 21 and the color of the detection line, and the results are shown in Table 1.

[0143] Table 1:

[0144]

[0145] After each indicator reacts, an obvious color change can occur. The intensity of the displayed color is also quite appropriate. Of course, in this embodiment, the ammonium salt can also be treated on the sample pad, and the alkaline buffer salt can be treated on the gas generating pad. When the urine sample is added to the sample pad, the ammonium salt flows with the sample to the gas generating pad and reacts with the alkaline buffer salt to generate ammonia gas.

[0146] Example 2: Figure 5 , Figure 6 , Figure 7 and Figure 8 the detection device described

[0147] The structure of the detection device 10 in this Example 2 is exactly the same as that in Example 1. The only difference is that the alkaline buffer salt is not treated on the sample pad 12. During the detection process, after adding the sample, the liquid alkaline buffer salt is immediately added to the sample pad 12. The alkaline buffer salt flows sequentially through the sample pad 12, the marking pad 13, and reaches the sample generating pad 16 to decompose the ammonium salt into ammonia gas. The released ammonia gas combines with the indicator on the indicating line 21 of the symbol display layer 2, causing the indicator 21 to change color and forming an obvious indicating line "-"; at the same time, the sample continues to flow through the gas generating pad 16 and reaches the detection pad for detection, thereby obtaining the detection result, that is, there is a detection line "|" or there is no detection line, thus presenting a symbol of "+" or "-".

[0148] In the test for hemoglobin in human feces, the feces sample is diluted with an alkaline buffer solution to obtain a sample dilution. The sample dilution is dropped onto the sample pad of the detection device described in this example, and at the same time, the alkaline buffer salt that triggers the generation of gas is also dropped onto the sample pad. The alkaline buffer salt flows sequentially through the sample pad 12, the marking pad 13, and reaches the sample generating pad 16 to decompose the ammonium salt to generate ammonia gas. The released ammonia gas combines with the indicator on the indicating line 21 of the symbol display layer 2, causing the indicator 21 to change color and forming an obvious indicating line "-". The marking pad 13 contains anti-human hemoglobin antibody labeled with latex, and the antibody that specifically binds to human hemoglobin is fixed on the detection pad. The dilution flows through the marking pad, the gas generating pad 16, and reaches the detection pad for detection, thereby obtaining the detection result, that is, there is a detection line "|" or there is no detection line, thus presenting a symbol of "+" or "-".

[0149] Of course, in this embodiment, after the sample is added to the sample pad 12, the alkaline buffer salt can also be added to the gas generating pad 16. The alkaline buffer salt reacts with the ammonium salt on the gas generating pad 16 to generate ammonia gas, and this ammonia gas contacts the indicator 21, causing the indicator 21 to change color.

[0150] Moreover, in this embodiment, the ammonium salt can also be treated on the sample pad 12, and after the sample is added to the sample pad 12, the alkaline buffer salt is immediately added to the sample pad 12, causing the ammonium salt to react with the alkaline buffer salt to generate ammonia gas.

[0151] Alternatively, in this embodiment, the ammonium salt can also be processed on the sample pad 12. After the sample is added to the sample pad, when the ammonium salt flows with the sample to the gas generating pad 16, an alkaline buffer salt is added to the gas generating pad 16 to make the ammonium salt react with the alkaline buffer salt to produce ammonia gas.

[0152] Embodiment 3: Figure 9 and Figure 10 The detection device described

[0153] like Figure 6 The detection device 10 for detecting urine samples shown in the figure comprises a detection layer 1 and a symbol display layer 2, wherein the symbol display layer 2 covers the top of the detection layer 1. The detection layer 1 comprises a base card 11, on which a sample pad 12, a marking pad 13, a detection pad 17 and a water-absorbing pad 8 are sequentially overlapped and pasted. One end of the symbol display layer 2 overlaps the sample pad 12, and the other end overlaps the water-absorbing pad 8, so that a space 22 is formed between the symbol display layer 2, the marking pad and the detection pad. The detection pad 17 comprises a detection line 171, and the symbol display layer 2 is provided with an indicator line 21 in the region of the detection line 171 on the detection pad 17, and the relative positional relationship between the indicator line 21 and the detection line 171 is in a cross shape. An indicator that changes color when encountering ammonia gas, such as bromophenol blue and bromocresol green, is included at the position of the indicator line.

[0154] In this embodiment, compared with the detection device in Example 1, a gas generating pad is provided less often, and it is usually used for the detection of ammonium salts contained in liquid samples, or ammonium salts added to the sample or to the detection device during detection.

[0155] In this embodiment, the sample pad 12 contains alkaline buffer salts. During the test, since the urine sample itself contains ammonium salts. When the urine passes through the sample pad 12, the pH of the urine sample increases under the action of the alkaline buffer salts of the sample pad 12. The ammonium salts in the urine decompose in an alkaline environment to generate ammonia gas and release it from the urine. The released ammonia gas diffuses to the symbol display layer 2, combines with the indicator on the indicator line 21 of the symbol display layer, causing the indicator 21 to change color, forming an obvious indicator line "-", and combined with the test results, a "+" or "-" symbol is presented, such as Figure 6 and 7 shown.

[0156] Embodiment 4: Figure 9 and Figure 10 The detection device described

[0157] The detection device in this Example 4 has the same structure as that in Example 3, except that the sample pad 12 does not contain an alkaline buffer solution. During the test, after the urine sample is added to the sample pad 12, an alkaline buffer solution is dropped onto the sample pad 12. The ammonium salts in the urine decompose under the action of the alkaline buffer salts to generate ammonia gas. The released ammonia gas combines with the indicator on the indicating line of the symbol display layer, causing the indicator to change color and forming an obvious indicating line, "-". Then, combined with the test result, the symbols "+" or "-" are presented.

[0158] Example 5

[0159] The device structure in this Example 5 is the same as that in Example 1 or Example 3, except that the ammonium salts used to generate gas can also be added separately to the liquid flow paths before the detection lines are generated, such as the sample pad, the marking pad, the gas generation pad, or the detection pad.

[0160] Example 6

[0161] The device structure in this Example 6 is the same as that in Example 1 or Example 3. The ammonium salts and the alkaline buffer salts can be separately treated on the sample pad, with a certain distance between them. That is, the ammonium salts and the alkaline buffer salts do not contact before the sample is added to the sample pad. However, when the sample flows on the sample pad, one of the ammonium salts and the alkaline buffer salts (the one treated upstream of the sample flow) is driven to the other, causing the two to react and generate gas to change the color of the indicator.

[0162] Example 7

[0163] The device structure in this Example 7 is the same as that in Example 1. The ammonium salts and the alkaline buffer salts can be separately treated on the gas generation pad, with a certain distance between them. That is, the ammonium salts and the alkaline buffer salts do not contact before the sample flows onto the gas generation pad. However, when the sample flows onto the gas generation pad, one of the ammonium salts and the alkaline buffer salts (the one treated upstream of the sample flow) is driven to the other, causing the two to react and generate gas to change the color of the indicator.

[0164] Example 8: Figure 11 and Figure 12 the described vertical flow detection device

[0165] such as Figures 11 to 12In the design solution, the detection device 10 is a detection structure for vertical liquid flow, including a symbol display layer 2 and a sample detection layer 1, and the symbol display layer 2 covers the sample detection layer 1; among them, the sample detection layer 1 includes a bottom plate 11 and a detection pad 17, and the detection pad 17 is located on the bottom plate 11. The detection pad 17 contains a reagent that reacts with the analyte; when needed, a reagent that can generate gas, such as an ammonium salt, is also processed on the detection pad 17. At both ends of the side of the bottom plate, there are adhesive blocks 3, and the symbol display layer 2 is adhered to the adhesive blocks and covers the detection pad 17. The adhesive block 3 can be a movable connection that fixes one end of the symbol display layer to the bottom plate 11 and the other end can be torn off and re-adhered repeatedly, or it can be a movable connection where both ends can be torn off and re-adhered repeatedly. An acid-base indicator is processed on the symbol display layer 2, and a space 22 is formed between the indicator 21 area and the detection pad 17, and the symbol display layer 2 can be separated from the adhesive block by tearing. During detection, one end of the symbol display layer 2 that is movably connected to the adhesive block 2 is torn off to expose the detection pad 17. After adding the sample and / or alkaline buffer salt to the detection pad 17, the torn symbol display layer 2 is adhered to the adhesive block 3 again. When the analyte exists in the sample, a detection line 171 appears on the detection pad 17. At the same time, in an alkaline environment, the ammonium salt in the sample or processed on the detection pad decomposes to release ammonia gas, and the generated ammonia gas contacts the indicator on the symbol display layer, and the indicator line 21 shows a color, forming a symbol of "+" or "-" with the detection line 171, Figure 15 As shown in, the indicator line 21 and the detection line 171 form a "+".

[0166] In a more specific embodiment, the vertical flow detection device 10 includes a substrate pad, a gas generation pad, a reaction pad, a separation pad 5 and an indicator pad 2. According to the characteristics of different products, the gas generation pad and the reaction pad can be unified into one layer to form the detection layer 1. The function of the separation pad 5 is to be breathable but not permeable to water. When a liquid sample is added to the detection device, the sample penetrates through the substrate pad, the gas generation pad and the reaction pad. The substance to be detected in the sample reacts with the pre-treated substance on the reaction pad to form an obvious line. At the same time, when the sample flows through the substrate pad and the gas generation pad, ammonia gas is also released. The ammonia gas permeates through the separation pad 5 to change the color of the indicator to form an obvious line. The line formed by the reaction of the substance to be detected and the indicator line form a "+".

[0167] For example, in a saliva alcohol detection product, the alcohol existing in the sample reacts with the enzyme and substrate on the reaction pad to form a blue line. At the same time, when the sample flows through the substrate layer and the gas generation layer, ammonia gas is also released. The ammonia gas permeates through the separation pad to change the color of the indicator to form an obvious line. The line formed by the reaction of alcohol and the indicator line form a "+".

[0168] Example 9: Figure 13 , Figure 14 andFigure 15 The described detection device

[0169] As Figures 13 to 15 shown in the design scheme, the detection device 10 is also a vertical flow detection structure. Compared with Embodiment 8, the detection layer 1 includes not only the bottom plate 11 and the detection pad 17, but also a gas generating pad 16, and the gas generating pad 16 and the detection pad 17 are sequentially pasted on the bottom plate 11. A substance for generating gas, such as ammonium salt, etc., is processed on the gas generating pad 16. The sticky blocks 3 are respectively located at both ends of the detection pad 17, and a symbol display layer 2 is covered on the sticky blocks 3, so that the symbol display layer 2 containing the indicator 21 covers above the detection pad. The detection pad 17 contains a reagent that reacts with the analyte. During detection, one end of the symbol display layer 2 connected to the sticky block 3 is torn off to expose the detection pad 17. After adding the sample and / or alkaline buffer salt to the detection pad 17, the torn symbol display layer 2 is stuck to the sticky block 3 again. When the analyte exists in the sample, a detection line 171 appears on the detection pad 17. The sample continues to flow vertically downward and contacts the gas generating pad. After contacting the ammonium salt processed on the gas generating pad 16, the ammonium salt decomposes to generate gas, and the generated gas contacts the indicator 21 on the symbol display layer, and the indication line appears, forming a "+" or "-" symbol with the detection line.

[0170] In this embodiment, ammonium salt and alkaline buffer salt can be processed on the gas generating pad 16 at the same time, and the two are not processed together. When the sample flows onto the gas generating pad, as the liquid flows, the alkaline buffer salt mixes with the ammonium salt to generate gas.

[0171] Embodiment 10: Figure 17 The described detection device

[0172] As Figure 17 shown in the design scheme, the detection device 10 is in the opposite position to the detection device 10 in Figure 13 , that is, from top to bottom are the sample pad 12, the gas generating pad 16, the detection pad 17 and the symbol display layer 2 in turn. The sample pad 12, the gas generating pad 16 and the detection pad 17 constitute the detection layer 1. When adding a sample to the sample pad 12, the sample flows into the gas generating pad 16 and the detection pad 17 in turn. After the generated gas contacts the symbol display layer 2, the indicator changes color, and the detection result is superimposed with the detection line to display a "+" or "-" symbol. Among them, ammonium salt can be processed on the sample pad 12, the gas generating pad 16 or the detection pad 17. Similarly, alkaline buffer salt can also be processed on the sample pad 12, the gas generating pad 16 or the detection pad 17. However, when the alkaline buffer salt and ammonium salt are processed on the same pad, the two are not processed at the same position to avoid premature reaction and gas generation.

[0173] Embodiment 11: Figure 18 , Figure 19 andFigure 20 Detection plate

[0174] As Figures 18 to 20 The detection plate 40 shown in the figure includes an upper plate 41, a lower plate 42 and a detection device 10. The detection device 10 can be a lateral flow test strip or a vertical flow test strip. The treatment substances and methods of the structure and components of the detection device 10 are also the same as those in Examples 1-10.

[0175] Figure 19 As shown, the detection device 10 is placed in the bottom plate 41 and fixed therein; a cover plate 42 is covered on the bottom plate 41 so that the detection device 10 is covered between the cover plate 42 and the bottom plate 41 of the detection plate. There is a sample addition hole 45 on the cover plate 42, and the position of the sample addition hole 45 corresponds to the position of the sample pad 12, so that the position of the sample pad 12 is exposed at the sample addition hole 45 of the detection plate 40, and the sample can be directly added to the sample pad 12 through the sample addition hole 45. There is also a window 43 on the cover plate 42 for observing the final detection result.

[0176] In some other embodiments, the window 43 is not covered with a transparent cover layer beforehand, but the symbol display layer 2 is directly covered at the window 43, and the indicator 21 is coated at the symbol display layer at the window position and is located above the detection line 171.

[0177] As Figure 20 The detection plate 40 shown in the figure includes an upper plate 41, a lower plate 42 and a detection device 10. The window 43 is covered with a transparent cover layer beforehand, and the symbol display layer is directly adhered to the window 43, and the indicator 21 is located at the window and is located above the detection line 171.

[0178] As Figure 17 The detection plate 40 shown in the figure includes an upper plate 41, a lower plate 42 and a detection device 10. The detection device 10 includes a sample detection layer 1 and a symbol display layer 2. The symbol display layer is adhered to the sample detection layer and has a certain gap with the sample detection layer. The detection device 10 is placed in the bottom plate 41, and a cover plate 42 is covered on the bottom plate 41 so that the detection device 10 is covered between the cover plate 42 and the bottom plate 41 of the detection plate.

[0179] As Figure 18 The detection plate 40 shown in the figure includes an upper plate 41, a lower plate 42 and a detection device 10. The detection device 10 is a vertical flow test strip, and more specifically, it is a detection device selected from Examples 6 to 8.

[0180] Example 12: Screening the substrate carrier for gas generation

[0181] Experimental procedure:

[0182] a. Treat 1% NH4Cl substrate solution on glass fiber, filter paper and polyester film respectively and dry for later use.

[0183] b. Assemble the treated glass fiber, filter paper, and absorbent rod on the sample pad of the test strip (such as the test strip in Example 1). Compare with the product without the substrate layer assembled.

[0184] c. Detect using 100 mIU / ml hCG urine standard. Record the appearance time of the indication line, color grade, and the color of the test line.

[0185] Experimental results:

[0186]

[0187] Conclusion: When the substrate is processed on carriers of different materials, it will affect the release rate of the substrate, thereby affecting the appearance time and intensity of the indication line. In the comparative experiment, although 1% NH4Cl substrate was not added to the test strip. However, since the urine itself contains ammonium salts, when the urine contacts the alkaline buffer of the test strip, ammonia is released and contacts the indicator, causing the indicator to change color. Also, due to the relatively low concentration of ammonium salts in the urine, the color of the indication line is relatively light. When a gas generating pad with an ammonium salt substrate is added to the test strip, it can overcome the disadvantages of uneven color development of the indication line due to different ammonium salt concentrations in the samples themselves. It ensures that the indication line of the detection results of different samples is uniform and the color depth is consistent.

[0188] Example 13: Influence of the existence of the indication line on the test line

[0189] Experimental procedure:

[0190] a. Assemble the transparent sheet with the treated indication line and the detection device with a gas generating pad together to form an hCG test strip (cross-signal hCG test strip). A common hCG test strip (without a gas generating pad) is used as a comparison and detected simultaneously.

[0191] b. Detect using 25 mIU / ml and 100 mIU / ml hCG urine standards. Record the color grade of the test line.

[0192] Experimental results:

[0193] Detection reagent 25 mIU / ml 100 mIU / ml Ordinary hCG reagent strip Faint detection line appears Obvious detection line appears Cross-signal hCG reagent strip Faint detection line appears Obvious detection line appears

[0194] Conclusion: The existence of the indication line structure will not affect the strength of the test line.

[0195] The detection device described in the present invention can be applicable to sample types including: liquid samples such as urine, blood, saliva, or samples that can be processed into a liquid for detection, such as feces, etc.

[0196] The color-changing indicator described in the present invention can also be a redox indicator, which can produce a color change when encountering an oxidizing substance or a reducing substance for the supporting reaction. For example, potassium dichromate itself is light yellow and can turn blue when encountering ethanol gas.

Claims

1. A detection device for detecting an analyte in a sample, comprising a sample detection layer, on which a detection line indicating whether the analyte is present in the sample is provided, characterized in that, It further includes a symbol display layer, on which an indicating line containing an indicator is provided; after adding a sample, whether the analyte in the sample exists or not, the indicator will contact a gas that can cause it to change color, so that the indicator changes from a first color to a second color; the positions of the detection line and the indicating line are arranged in a certain shape; the detection device further includes a gas generating agent for the gas that can cause the indicator to change from the first color to the second color; when the gas generating agent includes more than two substances, before the detection device is used, at least all of the more than two substances will not be mixed together.

2. The detection device according to claim 1, wherein The indicator on the symbol display layer does not contact the sample detection layer.

3. The detection device according to claim 2, wherein A gas channel is provided between the symbol display layer and the sample detection layer.

4. The detection device according to claim 3, wherein, A gas channel is provided between the result display area on the sample detection layer and the indicator area on the symbol display layer.

5. The detection device according to claim 2, characterized in that, A liquid barrier layer is provided between the symbol display layer and the sample detection layer.

6. The detection device according to claim 5, characterized in that The liquid barrier layer is transparent.

7. The detection device according to any one of claims 1-6, characterized in that The material of the symbol display layer is a transparent or semi-transparent material.

8. The detection device according to any one of claims 1-6, characterized in that, The shape is in a "cross" shape.

9. The detection device according to claim 1, characterized in that The gas generating agent is selected from alkaline buffer salts, or ammonium salts, or a combination of ammonium salts and alkaline buffer salts.

10. The detection device according to claim 1, wherein, All or part of the gas generating agent is disposed on the sample detection layer.

11. The detection device according to claim 1, characterized in that, The sample detection layer includes a detection pad; or the sample detection layer includes a detection pad and a sample pad; or the sample detection layer includes a detection pad, a sample pad and a marking pad; or the sample detection layer includes a detection pad, a sample pad, a marking pad and a water absorption pad.

12. The detection device according to claim 11, wherein, The sample detection layer includes a sample pad, a marking pad, a detection pad and a water absorption pad that are overlapped in sequence from upstream to downstream.

13. The detection device according to claim 11, characterized in that, The sample detection layer includes a gas generating pad.

14. The detection device according to claim 13, characterized in that, The sample detection layer includes a sample pad, a marking pad, a gas generating pad, a detection pad and a water absorption pad that are overlapped in sequence from upstream to downstream.

15. The detection device according to claim 13, characterized in that, The sample detection layer includes a sample pad, a gas generating pad and a detection pad that are stacked in sequence; or the sample detection layer includes a gas generating pad and a detection pad that are stacked in sequence.

16. The detection device according to claim 13, wherein The gas generating agent is selected from alkaline buffer salts, or ammonium salts, or a combination of ammonium salts and alkaline buffer salts; the alkaline buffer salt and the ammonium salt are separately disposed on one or two of the sample pad, the marking pad, the gas generating pad, the detection pad and the water absorption pad; when the ammonium salt and the alkaline buffer salt are disposed on the same pad, there is a certain distance between them.

17. The detection device according to claim 9, characterized in that, The alkaline buffer salt is selected from borax, Na2CO3 or K3PO4.

18. The detection device according to claim 9, characterized in that, The ammonium salt is selected from ammonium chloride or ammonium carbonate.

19. The detection device according to claim 1, characterized in that, The indicator is selected from acid-base indicators.

20. The detection device according to claim 19, wherein The acid-base indicator is selected from: p-nitrophenol, phenolphthalein, thymolphthalein, α-naphtholphthalein, phenol red, cresol red, bromophenol blue, thymol blue, methyl orange, neutral red, methyl red, bromothymol blue, litmus, TCTB, bromocresol green, bromocresol purple.

21. The detection device according to claim 1, wherein The analyte is hCG, LH, FSH, HCV, HBV, human immunodeficiency virus, any abused drug, creatinine, bilirubin, nitrite, protein, white blood cell, blood sugar, toxin or bacterium.

22. The detection device according to claim 1, characterized in that, The analyte is hemoglobin in feces, hepatitis B surface antigen, alcohol or heavy metal.

23. The detection device according to claim 1, characterized in that, The symbol display layer is located on the sample detection layer.

24. The detection device according to claim 1, wherein, The shape is used to indicate the situation of the analyte in the sample after the detection is completed.

25. A method capable of forming an easily recognizable detection result, characterized in that, Including the detection device according to any one of claims 1-24, after the indicator on the symbol display layer comes into contact with the gas that can cause it to change color, the indicator changes from the first color to the second color; a distinguishable detection result is formed between the indicator showing the second color and the detection line on the detection layer.

26. The method according to claim 25, wherein Trigger the gas generator added to the detection device to generate gas, or trigger the gas generator added to the detection device to generate gas.

27. A detection board, comprising an upper board and a lower board, characterized in that, It further includes the detection device according to any one of claims 1-24.

28. The detection board according to claim 27, wherein, A window is provided on the upper plate.

29. The detection board according to claim 28, wherein, The symbol display layer of the detection device covers the window.

30. The detection board according to any one of claims 27-29, characterized in that, The sample detection layer includes a sample pad, a labeling pad, a gas generation pad, and a detection pad that are sequentially overlapped from upstream to downstream. An alkaline buffer salt is processed on the sample pad, an hCG antibody with a label is coated on the labeling pad, an ammonium salt is processed on the gas generation pad, and an hCG antibody is coated on the detection line of the detection pad.

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