CN108802018B

CN108802018B - Method capable of visually reading detection result and manufacturing method of detection device

Info

Publication number: CN108802018B
Application number: CN201710297068.4A
Authority: CN
Inventors: 费凤琴; 张春霞; 商涛
Original assignee: Leadway HK Ltd
Current assignee: Leadway HK Ltd
Priority date: 2017-04-28
Filing date: 2017-04-28
Publication date: 2022-02-22
Anticipated expiration: 2037-04-28
Also published as: CN108802018A

Abstract

The invention relates to a method for visually reading a detection result, which comprises a detection device, a display device and a display device, wherein the detection device comprises a sample detection layer and a symbol display layer; the symbol display layer is positioned on the sample detection layer; the symbol display layer is processed with an indicator; upon contact of the indicator with a gas capable of changing its color, the indicator changes from a first color to a second color, forming an identifiable symbol with the test results on the sample detection layer. And a sample detection method and a method of manufacturing a detection device that can visually read a detection result. The method and the detection device for visually reading the detection result can stably and clearly display the detection result, so that a common operator can more visually obtain the detection result. Thereby the crowd and the scope that make detection device use are wider.

Description

Method capable of visually reading detection result and manufacturing method of detection device

Technical Field

The present invention relates to the field of testing, and more particularly to a test device for determining the presence or absence of an analyte in a sample and a method of manufacturing the test device, and a method of testing a sample using the test device and allowing visual reading of the test results.

Background

The existing detection device utilizing the lateral cross flow mode generally comprises a test strip, wherein a sample adding pad, a marking pad, a detection pad and a sample absorption pad are sequentially assembled on the test strip, and the detection pad comprises a detection line and a control line. The detection line is used for judging whether the analyte exists in the sample, if the analyte is displayed positively, the analyte exists in the sample, and if the analyte is displayed negatively, the analyte does not exist in the sample. The quality control line is used for checking and confirming whether the detection process is successful.

In order to more intuitively indicate whether an analyte is present in a sample, there have been a number of products that make a positive result indication of the position of a detection line from a "-" form to a "+" form. The test result is shown as a "+" sign when the analyte is present and as a "-" sign when the analyte is not present in the sample. The "+" and "-" signs are shown in a manner more consistent with the positive and negative result indications that people are used to.

For example, in US7537937, a test strip is provided with a color indicator line perpendicular to the test line, and is disposed under the test pad marked with the test line. In the testing process, the indication line below the detection pad material is shown by utilizing the principle that the detection pad material becomes transparent after liquid chromatography. When no analyte exists in the sample, the detection line on the detection pad does not appear, the color indication line on the test piece below the detection pad is displayed through the transparent detection pad, and the whole detection result is represented as a "-" symbol. When the analyte exists in the sample, a detection line appears on the detection pad, a color indication line on the test piece below the detection pad is simultaneously displayed through the transparent detection pad, and the detection line and the color indication line are displayed in a staggered manner and are shown as a plus sign. However, since the detection zone material also has some transparency in a dry condition, the indicator line can be seen invisibly before the product is tested, which affects the appearance of the product.

As in CN200510049177.1, the positive control area comprises a water-absorbent strip of water-absorbent material containing one or more components that exhibit a first color when dry and a second color when wet. Wherein, the vertical indicating line of the product is processed on a layer of water-absorbing strip (water-absorbing paper) by using water-encountering color-changing ink, then the water-absorbing paper is cut into required line size and is stuck below the detection area. In the test process, on one hand, the absorbent paper changes color, and on the other hand, the detection area material becomes transparent after liquid chromatography, so that the detection results respectively show two modes of + and-respectively.

The main problem of this processing method is that the production process is complicated and requires multi-step assembly and processing.

Disclosure of Invention

In view of the above problems, the present invention provides a new detection device and a method for manufacturing the detection device, so as to better realize the detection and result display of the detection device.

Specifically, the detection device provided by the invention comprises a sample detection layer, a symbol display layer and a detection reagent, wherein the sample detection layer is provided with the detection reagent reacting with an analyte and a result display area; the indicator changes from a first color to a second color upon contact with a gas that causes the indicator to change color.

Preferably, when the sample is added to the sample detection layer for detection, a gas that changes color of the indicator is generated and contacted with the indicator to change the indicator from a first color to a second color.

Preferably, the detection means further comprises a gas generating agent which generates a gas which causes a colour change in the indicator.

Preferably, the indicator is not in contact with the result display area of the sample detection layer.

Preferably, a gas passage is provided between the sample detection layer and the symbol display layer.

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.

Preferably, the result display area on the sample detection layer corresponds to the indicator area position on the symbol display layer. Specifically, the position of the indicator is in a superimposed or overlapping relationship with the position of the result display area in space, i.e. the result display area is projected to overlap the indicator area, more specifically, the indicator of the indicator area overlaps the detection line of the result display area, viewed vertically downward from above the symbol display layer.

Preferably, the symbol display layer is disposed on the sample detection layer, and the symbol display layer is made of transparent or semitransparent material capable of observing the detection result of the sample detection layer, and forms a recognizable symbol with the detection line on the sample detection layer when the indicator on the symbol display layer changes to a second color when encountering gas.

Preferably, the recognizable alignment is a "+" or "-" symbol.

In some embodiments, the symbol display layer is made of a water-impermeable material or a water-permeable material. Preferably, the symbol display layer is made of a waterproof material.

In some embodiments, the material of the symbol display layer is selected from materials that are not air permeable or have a weak air permeability. When the symbol display layer is a material that is not gas-permeable or has a weak gas-permeable effect, the indicator may be added to the side of the symbol display layer that is in contact with the gas, that is, the side adjacent to the sample detection layer (detection pad).

In other embodiments, the symbol display layer is made of a material selected from breathable materials. When the symbol display layer is made of a gas permeable material, the indicator may be added to the surface of the symbol display layer which is in contact with the gas or the other surface of the symbol display layer, or may be added to the middle of the symbol display layer or may be added to the middle of two gas permeable symbol display layers, and the gas changes the color of the indicator after the gas contacts the indicator.

In some preferred embodiments, the material of the symbol display layer is selected from transparent and gas-impermeable materials. Such as PV, PP, film, etc., in which case the indicator treatment is on the side of the symbol display layer overlying the sample detection layer. In other preferred embodiments, the symbol display layer is made of a transparent, air-permeable, water-impermeable material. For example: a water-permeable, air-impermeable film, a PTFE film, or the like, in which case the indicator is treated on either side of the symbol display layer.

In a preferred embodiment, a liquid barrier layer is arranged between the sample detection layer and the symbol display layer, and the material of the liquid barrier layer is selected from transparent air-permeable and water-impermeable materials. The liquid barrier layer separates the indicator from the detection layer, which is more beneficial to fixing the indicator on the symbol display layer. The liquid isolation layer may or may not be in contact with the symbol display layer and the sample detection layer. Such as: the liquid isolating layer is only in contact with the symbol display layer, or the liquid isolating layer is only in contact with the sample detection layer, or the liquid isolating layer is in contact with both the symbol display layer and the liquid isolating layer or not in contact with both the symbol display layer and the liquid isolating layer.

Preferably, the indicator and the gas generating agent are selected from an acid-base indicator and an acid-base reaction generating reagent in a matching and combining manner.

Preferably, the acid-base indicator is selected from bromothymol blue, bromocresol green and phenolphthalein, and the acid-base reaction generating reagent is selected from alkaline buffer salts or a combination of ammonium salts and alkaline buffer salts.

Preferably, the acid-base reaction generating reagent is processed on the sample detection layer; the ammonium salt and the alkaline buffer salt are separately treated on the sample detection layer without contacting the ammonium salt and the alkaline buffer salt before the sample is added on the sample detection layer.

Preferably, the sample detection layer comprises a detection pad, and the result display area is positioned on the detection pad.

Preferably, the sample detection layer further comprises a sample pad and a label pad; the sample pad and the marker pad are connected in series upstream of the detection pad.

Preferably, the sample detection layer further comprises a gas generation pad; the gas generating pad and the detection pad are located upstream of the detection pad.

Preferably, the gas generating pad is connected between the label pad and the detection pad. Preferably, the symbol display layer covers the detection pad and the gas generation pad; and a gas channel is arranged between the symbol display layer and the detection pad.

Preferably, the alkaline buffer salt and/or ammonium salt is treated separately on one or both of the sample pad, the label pad, the gas generation pad, or the detection pad; when the ammonium salt and the alkaline buffer salt are treated on the same pad body, a certain distance is formed between the ammonium salt and the alkaline buffer salt.

In a specific embodiment, when the acid-base reaction generating reagent is selected from alkaline buffer salts, the alkaline buffer salts are disposed on the sample pad, the label pad, the gas generating pad or the detection pad.

In another embodiment, when the acid-base reaction generating reagent is selected from the group consisting of ammonium salts and alkaline buffer salts, the ammonium salts and the alkaline buffer salts are respectively disposed on one or both of the sample pad, the label pad, the gas generating pad and the detection pad; when the ammonium salt and the alkaline buffer salt are treated on the same pad body, the ammonium salt and the alkaline buffer salt have a certain distance, namely, the ammonium salt and the alkaline buffer salt are positioned at different positions.

In a preferred embodiment, the gas generant pad is treated with an ammonium salt.

More preferably, the sample pad is treated with an alkaline buffer salt.

Preferably, the gas generant pad is treated with an alkaline buffer salt and an ammonium salt at different locations on the gas generant pad with a spacing therebetween.

Preferably, the sample detection layer further comprises a water absorbent pad connected downstream of the detection pad; one end of the symbol display layer covers the sample pad, and the other end of the symbol display layer covers the water absorption pad; the symbol display layer is not in contact with the marking pad, the detection pad and the gas generation pad, and a gas channel is formed.

In some preferred embodiments, the detection device further comprises a gas generating pad; the gas generating pad and the detection pad are in vertical flow connection, and the gas generating pad and the symbol display layer are respectively arranged on two sides of the detection pad.

Preferably, the device further comprises a sample pad, wherein the sample pad is connected to the side, which is not connected with the detection pad, of the gas generation pad.

Preferably, both end parts of one surface of the detection pad are provided with sticky blocks; the symbol display layer is connected with the detection pad through the adhesive block; and a gas channel is arranged between the symbol display layer and the detection pad.

In some vertical flow test sample systems, the sample is preferably not in contact with the symbol display layer when the sample is added to the test layer, so that the sample needs to be added to the test layer after the symbol display layer is opened. Therefore, the movable connection, or the separable connection, of the sample detection layer and the symbol display layer is to enable the symbol display layer to be separated from the sample detection layer. The movable connection structure has various modes, such as adhesion capable of tearing off adhesion, or buckling, or plugging and the like. One end of the sample detection layer and the symbol display layer can be movably connected, and the other end of the sample detection layer and the symbol display layer can be fixedly connected; or both ends can be movably connected.

In some embodiments, the alkaline buffer salt and/or ammonium salt is treated separately on one or both 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 body, a certain distance is formed between the ammonium salt and the alkaline buffer salt.

Preferably, the ammonium salt is treated on the gas generant pad. Preferably, the gas generant pad is also treated with an alkaline buffer salt that is treated at a different location on the gas generant pad than the ammonium salt.

Preferably, the ammonium salt is treated on the sample pad. Preferably, the sample pad is also treated with an alkaline buffer salt, which is treated at a different location on the sample pad than the ammonium salt.

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

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

The invention also provides a detection plate, which comprises a bottom plate and a cover plate, wherein the detection device is positioned between the bottom plate and the cover plate, the detection device comprises a sample detection layer, and a result display area is arranged on the sample detection layer.

Preferably, the symbol display layer is located on the cover plate, and the sample detection layer is located on the base plate.

Preferably, the sample detection layer comprises a detection pad, and the result display area is located on the detection pad.

Preferably, the sample detection layer further comprises a sample pad, a label pad and a water absorbent pad; the sample pad and the marking pad are sequentially connected to the upstream of the detection pad, and the water absorption pad is connected to the downstream of the detection pad.

Preferably, the sample pad is treated with one or both of an ammonium salt and an alkaline buffer salt; the ammonium and alkaline buffer salts were treated at different locations on the sample pad.

Preferably, the sample detection layer further comprises a gas generation pad; the gas generating pad is located between the marking pad and the detection pad.

Preferably, the detection plate cover plate is provided with a window and a sample adding hole, the position of the window corresponds to the detection result area, and the sample adding hole is positioned at the sample pad.

In addition, the invention also provides a sample detection method capable of reading the detection result visually, wherein the sample detection method comprises a detection device, a sample detection layer and a symbol display layer, wherein the detection device comprises a sample detection layer and a symbol display layer; the symbol display layer is positioned on the sample detection layer; the symbol display layer is processed with an indicator;

applying and flowing a fluid sample through a sample detection layer, the sample detection layer performing sample detection to create a detection line;

at the same time, the detection device generates gas which changes the color of the indicator;

contacting the indicator of the indicia displaying layer with a gas to change the indicator from a first color to a second color;

the indicator of the second color is superimposed with the detection line to form a recognizable symbol.

Preferably, the kit further comprises a gas generating agent which reacts to generate a gas which causes the indicator to change colour when the sample is applied to the detection device.

Preferably, all or a portion of the gas generant is disposed on the sample detection layer.

Preferably, the indicator is selected from bromothymol blue, bromocresol green, phenolphthalein; the gas generant is selected from the group consisting of alkaline buffer salts, ammonium salts and combinations of alkaline buffer salts.

Preferably, after applying the sample to the sample detection layer, an alkaline buffer salt is subsequently applied to the sample detection layer such that the alkaline buffer salt flows through the sample detection layer immediately following the flow of the fluid sample.

Preferably, the sample detection layer comprises a sample pad, a marking pad, a gas generation pad and a detection pad which are connected in sequence; treating an ammonium salt on a gas generation pad; the sample flows through the sample pad, the marking pad, the gas generation pad and the detection pad in sequence, gas is generated on the gas generation pad, and the sample generates a detection line on the detection pad.

In another aspect, the present invention also provides a method of manufacturing a detection device, comprising:

(1) preparing a sample detection layer: providing a test pad having a result display area and to be analyzed

A detection reagent for the reaction of the reagent is added on the detection pad;

(2) preparation of the symbol display layer: providing a transparent or translucent carrier, preparing the indicator solution, and

treating an indicator solution on said support, said indicator being contacted with a gas capable of causing a colour change thereof,

changing from a first color to a second color;

(3) assembling the sample detection layer of step 1 and the symbol display layer of step 2, and allowing

The indicator is not in contact with the result display area of the sample detection layer;

(4) a gas generating agent capable of generating a gas that discolors an indicator is provided.

Preferably, part or all of the gas generant is disposed on the detection layer.

Preferably, the sample detection layer includes a detection pad, a sample pad, and a label pad, which are connected to each other in order in the direction of the flow of the liquid, and the gas generating agent is disposed on at least one of the sample pad, the label pad, and the detection pad.

Preferably, the gas generating pad is arranged at any position in front of the detection pad, and the gas generating agent is added on the gas generating pad.

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

Preferably, the indicator is selected from bromothymol blue, bromocresol green, phenolphthalein, and the gas generant is selected from the group consisting of an alkaline buffer salt, an ammonium salt, and a combination of alkaline buffer salts.

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

Preferably, ammonium chloride or ammonium carbonate or the like is prepared as a 1% solution and is disposed on the sample detection layer.

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

Preferably, the symbol display layer is made of a transparent or translucent water-impermeable material.

Preferably, a liquid barrier layer is arranged between the sample detection layer and the symbol display layer, and the material of the liquid barrier layer is selected from transparent air-permeable and water-impermeable materials.

The invention also provides a method for visually reading the detection result, which comprises a detection device, a display device and a display device, wherein the detection device comprises a sample detection layer and a symbol display layer; the symbol display layer is positioned on the sample detection layer; the symbol display layer is processed with an indicator; upon contact of the indicator with a gas capable of changing its color, the indicator changes from a first color to a second color, forming an identifiable symbol with the test results on the sample detection layer.

Advantageous effects

The device and the detection board can stably and definitely display the detection result, so that an ordinary operator can obtain the detection result more intuitively. Thereby the crowd and the scope that make detection device use are wider.

Drawings

FIG. 1 is a schematic view of a detection device of the present invention;

FIG. 2 is a schematic view of another detection device of the present invention;

FIG. 3 is a schematic view of another detection device of the present invention;

FIG. 4 is a schematic view of another detection device of the present invention;

FIG. 5 is a schematic view of a particular detection device of the present invention;

FIG. 6 is a top view of the device of FIG. 5 (positive test result display);

FIG. 7 is another top view of the device of FIG. 5 (negative test result display);

FIG. 8 is an exploded schematic view of the apparatus of FIG. 5;

FIG. 9 is a schematic view of another embodiment of the detection device of the present invention;

FIG. 10 is an exploded schematic view of the apparatus of FIG. 9;

FIG. 11 is a schematic view of a further embodiment of the detection device of the present invention;

FIG. 12 is a front view of the detection device of FIG. 11;

FIG. 13 is a schematic view of another detection device of the present invention;

FIG. 14 is a cross-sectional view of the test device of FIG. 13;

FIG. 15 is an exploded view of the detection device of FIG. 13;

FIG. 16 is a schematic view showing a result display area superimposed with an indicator area (positive detection result display);

FIG. 17 is a schematic view of another detection device of the present invention;

FIG. 18 is a schematic view of the structure of the detection plate of the present invention;

FIG. 19 is an exploded view of the sensing plate of FIG. 18;

FIG. 20 is another exploded view of the sensing plate of FIG. 18;

reference numerals:

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, (detection) result display area 18, detection pad 17, gas generation pad 16, marking pad 13, sample pad 12, absorbent pad 8, bottom card 11, detection line 171, quality control line 172, sticky block 3, detection plate 40, bottom plate 41, cover plate 42, window 43, sample adding hole 45, space/gas channel 22

Detailed Description

The present invention will be further described with reference to the structures or terms used herein.

Detection of

"detecting" means assaying or testing for the presence of a substance or material, such as, but not limited to, a chemical, organic compound, inorganic compound, metabolic product, drug or drug metabolite, organic tissue or a metabolite of organic tissue, nucleic acid, protein, or polymer. In addition, detection indicates the amount of the test substance or material. Further, the assay means immunodetection, chemical detection, enzyme detection, and the like.

Type of sample

Any type of sample can be tested with the device of the present invention, including bodily fluids (e.g., urine and other bodily fluids, as well as clinical samples). Liquid samples may be derived from solid or semi-solid samples, including stool, biological tissue, and food samples. These solid and semi-solid samples may be converted to liquid samples by any suitable method, such as mixing in a suitable liquid, mincing, macerating, incubating, dissolving, or enzymatically hydrolyzing the solid sample (e.g., water, phosphate buffer, or other buffer). "biological samples" include samples derived from living animals, plants and food, and also include 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 therein, whether human or animal. Food samples include processed food ingredients and end products, meat, cheese, wine, milk and drinking water. Plant samples include samples derived from any plant, plant tissue, plant cell culture, and conditioned medium therein. "environmental samples" are those samples derived from the environment (e.g., lake water samples or samples of other bodies of water, sewage samples, soil samples, groundwater samples, seawater samples, samples of waste water). Sewage and associated waste may also be included in the environmental sample.

Type of analyte

Examples of analytes that can be stably detected in the present invention include, but not exclusively, human chorionic gonadotropin (hCG), Luteinizing Hormone (LH), ovarian estrogen (FSH), Hepatitis C Virus (HCV), Hepatitis B Virus (HBV), hepatitis b surface antigen, hiv and any drugs of abuse. The analyte can be detected in any liquid or liquefied sample, such as urine, saliva, blood, plasma, or serum. Examples of other analytes are creatinine, bilirubin, nitrite, proteins (non-specific), blood, leukocytes, blood glucose, heavy metals and toxins, bacterial components (e.g., specific proteins and sugars of a particular type of bacteria, such as E.coli 0157: H7, Staphylococcus aureus, Salmonella, Clostridium perfringens, Campylobacter, Listeria monocytogenes, Vibrio enteritidis, or Bacillus cereus). Any other analyte suitable for lateral flow assay formats may be detected with the present device. The invention is explained in more detail below with reference to the figures and examples, without limiting the scope of the invention.

The detection device 10 of the present invention comprises two parts: a sample detection layer 1 and a symbol display layer 2; the symbol display layer 2 is processed with an indicator 21 which can change color; the detection device 10 is formed by the combination of these two parts, as shown in FIG. 1. The detection device 10 can display easily identified detection results or detection information after the sample is detected. Specifically, the symbol display layer 2 changes color by the indicator 21 to form a display symbol that can represent the detection information or the detection result of the detection device 10. The shape of the indicator 21 disposed on the symbol display layer 2 can be set as desired, so that the symbol displayed after changing color is the same as the indicator shape, such as: numbers, 1, 0, etc.; simple patterns, -, ×, Δ, etc.; characters; letters, Y, N, etc.; the shape of the symbol may be set by the indicator representation according to the needs of the detection apparatus 10.

In some preferred embodiments, the indicator on the symbol display layer 2 is not in contact with the sample detection layer 1. More specifically, the indicator-containing region 23 of the symbol display layer 2 is not in contact with the sample detection layer 1, and as shown in fig. 2 and 3, the bottom surface of the symbol display layer 2 is in direct contact with the sample detection layer 1 and covers the sample detection layer 1, and the indicator 21 is disposed on the upper surface of the symbol display layer 2 (i.e., the surface not in contact with the sample detection layer). In a specific embodiment, a gas channel is arranged between the sample detection layer and the symbol display layer; alternatively, 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, as shown in fig. 5, 9 and 11, when the indicator 21 is disposed on the side 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 and the detection layer 1 are not in contact, and the gap or space 22 is the gas channel 22 through which the gas is volatilized.

The positions of the sample detection layer 1 and the symbol display layer 2 on the detection device 10 may be such that the symbol display layer 2 covers a part or all of the sample detection layer 1. As shown in fig. 2, the symbol display layer 2 covers a part of the sample detection layer 1; as in fig. 3, the symbol display layer 2 covers the entire sample detection layer 1. Or the sample detection layer 1 and the symbol display layer 2 are at different positions of the detection device 10, i.e. the two layers do not overlap each other on the vertical projection plane.

The indicator changes from a first color to a second color upon contact with a gas that changes color, the second color displaying a symbol that may be used to indicate what test item the test device 10 is being used for. For example, in a detection device for detecting drug abuse, the indicator shape of the symbol display layer is different from each other, and in a detection device for detecting the intake of morphine, the indicator shape of the symbol display layer is MOP (which is an acronym for morphine). A test device for testing cocaine ingestion comprises a symbol display layer indicator in the form of COC (COC for cocaine). For example, in one embodiment, after the sample is added to the detection layer, the gas is generated by the liquid sample itself or by the trigger of the sample, so that the indicator shows the symbol COC, which indicates that the detection item of the detection device is cocaine.

The symbol displayed in the second color after the indicator color is changed can also be matched with the detection line of the sample detection layer to form an identifiable symbol which is easy to read by a user. In some embodiments, as shown in fig. 2 and 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. I.e. the position of the indicator area 23 is in a superimposed or overlapping spatial relationship with the position of the result display area 18. The color symbols formed by the indicators 21 can thus be superimposed on the detection lines 171 on the sample detection layer 1, i.e. the indicator color symbols form a new symbol after being projected perpendicular to the detection lines in a plane, as shown in fig. 6 and 7 and fig. 16, forming one or more easily understandable and recognizable result displays. FIG. 6 shows that after the sample is applied and the analyte is present or reaches a predetermined level, a detection line 171 appears on the sample detection layer and forms a "+" symbol with the colored indicator 21; in fig. 7, after the sample is added and the analyte is not present in the sample or the amount of the analyte does not reach the predetermined value, the result of the sample detection layer shows that the detection line 171 does not appear in the result display area, and the colored indicator 21 alone shows a "-" type symbol. Such symbols indicate that the interpretation habits of people in positive and negative tests are met, and people are used to indicate positive with "+" and negative with "-". In the detection of a conventional lateral flow test strip, the detection result is usually displayed with one detection line or without one detection line, and in the judgment of a conventional operator, the result is wrong due to unfamiliarity. In the present invention, the "+" or "-" symbol may be formed by the superposition of the color symbol of the disclosing agent and the detection line. Of course, the results of the superimposed detection may be in various forms, for example, the indicator may be "O", and the combination with the results of the detection may result in a detection result showing a negative or positive contrast such as "Φ", "Θ", or "O".

The indicator 21 of the symbol display layer displays the symbol by changing color, which may be from one color to another, so that the operator acquires the detection information by the change of color. For example, the color is changed from colorless to red, from light color to dark color, from red to green, blue, etc.; or, the color is changed from red to colorless, and from dark to light. Specifically, in general, in a detection device in which a detection line shows a recognizable color, i.e., a positive result after completion of detection, in order to prevent erroneous operation, the indicator is usually changed from a colorless state to a color that is easy to observe, or the indicator is changed from a first color to a second color after detection, the first color being the same as or similar to the background color of the detection pad 17. The indicator 21 is colorless or a color close to the bottom color of the detection pad before the detection is started, which is not easily perceived by the user, and this can prevent the user from mistakenly recognizing that the detection device which is not actually used has been used, compared to the case where the first color of the indicator is a color which is easily perceived. In the detecting device in which the detection line shows a recognizable color after the detection, i.e., a negative result, the indicator may be changed from an easily observable color to a colorless color, or the second color of the indicator may be the same as or similar to the background color of the detection pad.

The color change is effected by reaction of the indicator upon contact with a gas. This type of color-changing reaction is of many types, for example, acid-base indicating reactions.

The indicator is selected from acid-base indicators, such as nitrophenol, phenolphthalein, sulphophenolphthalein, azo compounds and other acid-base indicators; specifically, p-nitrophenol, phenolphthalein, thymolphthalein, alpha-naphtholphthalein phenol red, cresol red, bromophenol blue, thymol blue, methyl orange, neutral red, etc. More specifically, for example, there are selected methyl orange and methyl red which are orange in an acidic environment and yellow in an alkaline environment, bromothymol blue which is yellow in an acidic environment and blue in an alkaline environment, phenolphthalein which is colorless in an acidic environment and red in an alkaline environment, and litmus which is red in an acidic environment and blue in an alkaline environment. Different acid-base indicators can generate color change when meeting acid gas or alkaline gas of matched reaction.

The gas that triggers the color change of the indicator 21 is generated by a gas generating agent, and specifically, the gas may be generated by mixing different substances that do not mix with each other when the detection device 10 is not in use, or by mixing different substances with a liquid sample that at least do not mix all together, so that the gas is generated and released before being held free, resulting in the gas not being able to contact the indicator 21 on the detection device. For example, in the case of using ammonia gas to contact the bromophenol blue indicator to change the indicator from a pale yellow color to a blue color, the ammonia gas-generating substances include ammonium chloride and an alkaline buffer salt. Ammonium chloride and alkaline buffer salt are added at different positions of the detection pad and are not in contact with each other; or ammonium chloride and an alkaline buffer salt are added on different ones of the sample pad 12, the label pad 13 and the detection pad 17, respectively; alternatively, if the test device 10 includes a gas generating pad, one reagent of ammonium chloride or a basic buffer salt may be added to the gas generating pad 16 and the other reagent may be added at other locations where the fluid flows, such as one or more of the sample pad 12, the label pad 13, or the test pad 17. Or one of ammonium chloride and an alkaline buffer salt is formulated in solution for use, and the other reagent is added to one or more of the sample pad 12, the label pad 13, the gas generation pad 16, or the detection pad 17, and a solution reagent is added to allow the ammonium chloride and the alkaline buffer salt to mix to generate a gas during detection. Or preparing the ammonium chloride and the alkaline buffer salt into solutions, adding the two solutions into a detection device during detection, and mixing to generate ammonia gas.

The generated gas may also combine with moisture in the test space, causing the indicator to react and undergo a color change.

In some embodiments, the acid indicator 21 on the symbol display layer 2 is colored by ammonia gas generated by decomposition of ammonium salt in an alkaline environment. More specifically, some samples, such as urine samples, which have ammonium salts themselves, are mixed with alkaline buffer salts to decompose and generate ammonia gas while the samples are added into the detection device for detection, so that the acidic indicator changes from a first color to a second color to display the indicator symbol, or the indicator symbol is superposed with the detection result line to form a result display symbol. In other embodiments, the ammonium salt may be treated on the detection layer 1, and an alkaline buffer salt may be added simultaneously with the addition of the sample, so that the ammonium salt will desorb ammonia gas in an alkaline environment, causing the indicator 21 to change color. In some preferred embodiments, the sample itself contains an ammonium salt, and when the sample is added to the detection layer 1, the sample is subjected to an alkaline environment, which generates ammonia gas, causing the indicator 21 to change from a first color to a second color. In some embodiments, the alkaline buffer salt is selected from borax, NaCO3, K3PO4, and the like.

In a more specific embodiment, as shown in FIG. 4, the test device 10 may include a liquid barrier layer 5 between the sample test layer 1 and the symbol display layer 2, the liquid barrier layer 5 functioning as a gas-permeable and water-impermeable barrier. And the liquid barrier layer 5 is transparent. After the liquid sample is added to the detection layer, the substance to be detected in the sample reacts with the substance pretreated on the detection layer 1 to form an obvious line-detection line. Meanwhile, when the sample flows through the detection layer 1, gas is released to permeate the liquid barrier layer 5, so that the indicator 21 processed on the symbol display layer 2 is discolored to form a second color line. The line generated by the reaction of the substance to be detected forms a "+" or "-" with the indicator line.

The material of the symbol display layer 2 may be transparent or semitransparent material, so as to facilitate observation of the covered detection result region. The material of the symbol display layer 2 can be a waterproof material, and the material of the symbol display layer 2 can be a breathable or air-proof material; such as PTFE films, air and water impermeable films, PET, PE, PP, etc. When the symbol display layer 2 is made of a gas impermeable material, the indicator 21 is located on the side of the symbol display layer 2 adjacent to the sample detection layer. When the symbol display layer 2 is made of a breathable material, the indicator 21 may be located on a surface of the symbol display layer 2 adjacent to the sample detection layer or a surface of the symbol display layer away from the sample detection layer, that is, the indicator 21 may be located on a front surface or a back surface of the symbol display layer. Of course, when the liquid barrier layer 5 is provided between the symbol display layer 2 and the sample detection layer 1, the symbol display layer 2 may be made of a water-permeable material.

In some embodiments, the sample detection layer 1 includes a detection pad 17, the detection pad 17 has a detection result display region 18 thereon, and the symbol display layer 2 is overlaid on the detection pad 17 such that the indicator region 23 corresponds to the detection result display region 18, i.e., the two are spatially overlapped or superposed, as shown in fig. 5. In this way, the indicator 21 may be superimposed with the detection result 171 to form a recognizable symbol, as shown in fig. 6 and 7.

Also as shown in FIG. 5, in some embodiments, the sample detection layer 1 further comprises a gas generating pad 16, and the gas generating pad 16 is used for generating gas, so that the gas generating pad 16 is treated with ammonium salt, and after the sample flows through the gas generating pad 16, the ammonium salt decomposes to generate ammonia gas in an alkaline environment to change the color of the indicator 21.

In a more specific embodiment, the sample detection layer 1 further comprises a label pad 13, a sample pad 12, wherein the sample pad 12 and the label pad 13 are connected in sequence upstream of a gas generation pad 16, and the gas generation pad 16 is connected upstream of a detection pad 17, i.e., a sample flows through the sample pad 12, the label pad 13, the gas generation pad 16 and the detection pad 17 in sequence. In another embodiment, detection layer 1 further comprises an absorbent pad 8 attached downstream of detection pad 17 and a back card 11 holding sample pad 12, label pad 13, gas generating pad 16 and detection pad 17, absorbent pad 8. At this time, the sample pad 12 may be treated with an alkaline buffer salt, and after the sample is added to the sample pad 12, the alkaline buffer salt is driven to flow to the gas generation pad 16, so that the ammonium salt on the gas generation pad 16 is decomposed into ammonia gas in an alkaline environment.

In other embodiments, the location of the gas generant pad 16 on the detection device 10 may be selected as desired so long as the gas generated by the gas generant pad 16 contacts the indicator 21 on the indicia display layer 2.

In some embodiments, the symbol display layer 2 is connected to the sample pad 12 at one end and the absorbent pad 8 at the other end, so that a space is formed between the symbol display layer 2 and the marker pad 13, the gas generation pad 16 and the detection pad 17, and the space is a gas channel, which is more favorable for gas diffusion. This space may be open or closed.

In some embodiments, the symbol display layer 2 and the sample detection layer 1 may be fixedly connected, or may be removably connected or detachably connected. For example, the symbol display layer 2 is directly bonded and fixed with the sample detection layer 1; alternatively, the sample detection layer 1 is fixed to a base plate, and the symbol display layer 2 is fixed to a cover body, and when the cover body is closed with the base plate, the symbol display layer 2 is covered on the sample detection layer 1, as shown in fig. 20. Still alternatively, the end of the symbol display layer 2 is fixed to the sample detection layer 1 by a tearable adhesive tape, as shown in fig. 11, and so on. In some more preferred embodiments, the symbol display layer 2 forms a space 22 with the sample detection layer 1, such that the indicator area 23 of the symbol display layer is at a distance from the detection layer 1, as shown in FIG. 5.

In some embodiments, as shown in FIG. 11, the end of the sample detection layer of the detection device is protruded 3, and the end of the symbol display layer is connected to the protruded 3, so that the symbol display layer 2 and the sample detection layer 1 are connected to each other in a covering manner, and a space 22 is formed therebetween. Wherein the indicator area corresponds to the result display area position overlay, as shown in fig. 11 and 16.

The detection device of the present invention will be described below with respect to specific embodiments.

Example 1: the detection devices depicted in fig. 5, 6, 7 and 8

A lateral flow assay device 10 for detecting hCG in urine, as shown in figure 5, comprises a detection layer 1 and a symbol display layer 2, wherein the symbol display layer 2 covers the detection layer 1, and a certain space is reserved between the detection layer 1 and the symbol display layer 2 as a channel 22 for gas volatilization. Specifically, the detection layer 1 includes a base card 11, and a sample pad 12, a marker pad 13, a gas generating pad 16, a detection pad 17, and a water absorbent pad 8 are attached to the base card 11 in this order while being overlapped with each other, as shown in fig. 5. The symbol display layer 2 is overlapped on the sample pad 12 at one end and on the absorbent pad 8 at the other end, so that a space 22 is formed between the symbol display layer 2 and the marker pad, the gas generation pad and the detection pad. The sample pad 12 is used to receive a test sample and deliver the sample to a functional pad (e.g., a label pad, a test pad, etc.) downstream thereof. In this example, the label pad 13 is coated with a colloidal gold-labeled anti-hCG antibody (labeled antibody) that binds to hCG antigen in the sample to form a first binding substance. The detection pad 17 is provided with at least a detection line 171, in this embodiment, the detection line 171 is coated with hCG antibody, and the first binding substance flowing onto the detection pad is combined with the anti-hCG antibody on the detection line to form a macroscopic line. If the content of hCG in the urine is lower than the lowest detection threshold, no visible line can be formed on the detection line. A quality control line 172 may be further included on the detection pad 17, wherein the quality control line 172 is used to indicate whether the detection is successfully completed.

Solutions were prepared with different types of indicators shown in Table 1 at a certain concentration. The prepared indicator solution is then processed separately on different transparent plastic sheets to form the indicating lines 21 (the transparent plastic sheet in this example is the symbol display layer 2 according to the present invention). And assembling the side, adjacent to the sample detection layer, of the transparent sheet with the indicator together with the sample detection layer, wherein the indicator line is positioned right above the detection line to form a cross.

In one 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.

In this embodiment, an ammonium salt, such as ammonium chloride or ammonium carbonate, is formulated as a 1% aqueous solution and treated on gas generation pad 16 by soaking or the like, and sample pad 12 is treated with an alkaline buffer salt. For example, the alkaline buffer salt is 100mM Tris buffer, pH8.0, and after immersing the sample pad in the buffer, a sample pad with alkaline buffer is obtained. The soaked gas generation pad and sample pad are assembled into the detection device in a dry state. During testing, the pH of the sample increased after mixing with the sample pad alkaline buffer salt. When the ammonium salt in the gas generation pad is contacted with the alkaline sample, the ammonium salt is decomposed to generate ammonia gas and is released. The sample brings gaseous ammonia in the chromatographic process, and the gaseous ammonia is contacted with the indicator in the transparent plastic sheet, and the color of the indicator is changed.

When the hCG content in the sample is higher than the lowest detection value, a color line visible to the naked eye is formed on the detection line 171 of the detection pad. The color lines spatially coincide with the indication lines on the symbol display layer 2 by "+". The examiner can judge the sample as positive according to the appearance of "+" as shown in FIG. 6. If the hCG content in urine is lower than the minimum detection value, a colored line is not formed on the detection line of the detection pad, and a visible indication line appears only on the detection line of the symbol display layer, thereby forming a "-" symbol, as shown in fig. 7. The examiner judges the sample as negative according to "-".

The assay was performed with a urine standard containing 100mIU/ml hCG. The color of the indicator line 21 and the color of the detection line were recorded, and the results are shown in table 1.

Table 1:

each indicator reacts to produce a distinct color change. The intensity of the display color is also suitable. Of course, in this embodiment, the ammonium salt may be treated on the sample pad, and the alkaline buffer salt may be treated on the gas generation pad. After the urine sample is added to the sample pad, the ammonium salt flows to the gas generation pad along with the sample to react with the alkaline buffer salt to generate ammonia gas.

Example 2: the detection devices depicted in fig. 5, 6, 7 and 8

The test device 10 of this example 2 is identical in structure to that of example 1, except that no alkaline buffer salt is disposed on the sample pad 12. In carrying out the assay, a sample pad 12 of liquid alkaline buffer salt is added immediately after the sample is added. The alkaline buffer salt flows through the sample pad 12, the marker pad 13, and reaches the sample generation pad 16 in order to decompose the ammonium salt into ammonia gas. The released ammonia gas combines with the indicator on the indicator line 21 of the symbol display layer 2 to cause the indicator 21 to change color to form a clear indicator line "-"; at the same time, the sample continues to flow through gas generation pad 16 to the detection pad for detection, resulting in a detection result, i.e., either with or without a detection line, thus presenting a "+" or "-" sign.

In the hemoglobin test in human stool, a stool sample is diluted by an alkaline buffer solution to obtain a sample diluent, the sample diluent is dripped on a sample pad of the detection device in the embodiment, and meanwhile, alkaline buffer salt which triggers gas generation is also dripped on the sample pad. The alkaline buffer salt flows through the sample pad 12, the marker pad 13, and reaches the sample generation pad 16 to decompose the ammonium salt to generate ammonia gas. The released ammonia gas combines with the indicator on the indicator line 21 of the symbol display layer 2 to cause the indicator 21 to change color to form a clear indicator line "-". The labeled pad 13 contains latex-labeled anti-human hemoglobin antibody, and the antibody specifically binding human hemoglobin is fixed on the detection pad. The diluent flows through the label pad, the gas generation pad 16, to the detection pad for detection, resulting in a detection result, i.e. either with a detection line "|" or without a detection line, thus presenting a "+" or "-" sign.

Of course, in this embodiment, after the sample is added to the sample pad 12, an alkaline buffer salt may be added to the gas generation pad 16, and the alkaline buffer salt reacts with the ammonium salt on the gas generation pad 16 to generate ammonia gas, which comes into contact with the indicator 21 to change the color of the indicator 21.

In this embodiment, the ammonium salt may be treated on the sample pad 12, and the alkaline buffer salt may be added to the sample pad 12 immediately after the sample is added to the sample pad 12, so that the ammonium salt and the alkaline buffer salt react to generate the ammonia gas.

Alternatively, in this embodiment, the ammonium salt may be treated on the sample pad 12, and when the ammonium salt flows to the gas generation pad 16 along with the sample after the sample is added to the sample pad, an alkaline buffer salt may be added to the gas generation pad 16, so that the ammonium salt and the alkaline buffer salt react to generate ammonia gas.

Example 3: the detection device depicted in fig. 9 and 10

The detecting device 10 for detecting a urine sample shown in FIG. 6 comprises a detecting layer 1 and a symbol display layer 2, wherein the symbol display layer 2 is covered on the detecting layer 1. The detection layer 1 comprises a bottom card 11, and a sample pad 12, a marking pad 13, a detection pad 17 and a water absorption pad 8 are sequentially adhered to the bottom card 11 in a mutually overlapped manner. The symbol display layer 2 is overlapped on the sample pad 12 at one end and on the absorbent pad 8 at the other end, so that a space 22 is formed between the symbol display layer 2 and the marker pad and the detection pad. The detection pad 17 includes detection lines 171, the symbol display layer 2 is provided with indication lines 21 in the areas of the detection lines 171 on the detection pad 17, and the indication lines 21 and the detection lines 171 are in a crisscross relationship with each other. Indicator which changes color when meeting ammonia gas, such as bromophenol blue and bromocresol green, is contained at the position of the indicating line.

In this example, compared with the detection device in example 1, a gas generating pad is less provided, and is generally used for detecting ammonium salts in a liquid sample, or ammonium salts added to the sample or ammonium salts added to the detection device during detection.

In this embodiment, the sample pad 12 includes an alkaline buffer salt thereon. When tested, the urine sample contains ammonium salt. As the urine passes through the sample pad 12, the pH of the urine sample rises under the action of the sample pad 12 alkaline buffer salt. The ammonium salt in the urine is decomposed under the alkaline environment to generate ammonia gas and is released from the urine. The released ammonia gas diffuses to the site of the symbol display layer 2, combines with the indicator on the indicator line 21 of the symbol display layer to cause the indicator 21 to change color to form a clear indicator line "-", and combines with the detection result to present a symbol of "+" or "-", as shown in fig. 6 and 7.

Example 4: the detection device depicted in fig. 9 and 10

This example 4 is identical in structure to the detecting unit of example 3 except that no alkaline buffer solution is contained on the sample pad 12. During testing, after a urine sample is added into the sample pad 12, an alkaline buffer solution is dripped onto the sample pad 12, ammonium salt in the urine is decomposed under the action of alkaline buffer salt to generate ammonia gas, the released ammonia gas is combined with the indicator on the indicator line of the symbol display layer to cause the indicator to change color, an obvious indicator line, "-", is formed, and then a detection result is combined, so that a "+" or "-" symbol is presented.

Example 5

The apparatus of example 5 has the same structure as that of example 1 or example 3, except that an ammonium salt for generating a gas may be added to the liquid passage before the detection line is generated, such as the sample pad, the label pad, the gas generation pad, or the detection pad.

Example 6

The device of this example 6 has the same structure as that of example 1 or example 3, and ammonium salt and alkaline buffer salt can be separately treated on the sample pad with a certain distance therebetween. That is, the ammonium salt and the alkaline buffer salt are not contacted before the sample is added to the sample pad, and when the sample flows on the sample pad, one of the ammonium salt and the alkaline buffer salt (the one treated upstream in the flow of the sample) is brought to the other, so that the ammonium salt and the alkaline buffer salt react with each other to generate gas to change the color of the indicator.

Example 7

The device of example 7 was constructed as in example 1, and ammonium salt and alkaline buffer salt were separately treated on the gas generation pad with a distance therebetween. That is, the ammonium salt and the alkaline buffer salt are not in contact before the sample flows onto the gas generation pad, and when the sample flows onto the gas generation pad, one of the ammonium salt and the alkaline buffer salt (the one disposed upstream of the flow of the sample) is brought to the other, so that the ammonium salt and the alkaline buffer salt react with each other to generate gas to change the color of the indicator.

Example 8: vertical flow detection device as described in fig. 11 and 12

In the embodiments shown in fig. 11 to 12, the detecting device 10 is a vertical flow detecting structure of liquid, and includes a symbol display layer 2 and a sample detecting layer 1, wherein the symbol display layer 2 covers the sample detecting layer 1; wherein, the sample detection layer 1 comprises a bottom plate 11 and a detection pad 17, and the detection pad 17 is positioned on the bottom plate 11. The detection pad 17 contains a reagent that reacts with the analyte; the detection pad 17 is also treated with a gas generating reagent, such as an ammonium salt, if necessary. Both ends side has sticking block 3 on the bottom plate, and symbol display layer 2 glues on sticking block and covers in detecting pad 17 top, and this sticking block 3 can be to make symbol display layer one end fixed connection on bottom plate 11, and the other end can be torn repeatedly and bonded swing joint again, also can be that both ends are can tear repeatedly and bond swing joint again. The symbol display layer 2 is processed with an acid-base indicator, 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 sticky block in a tearing way. During detection, one end of the symbol display layer 2 movably connected on the sticky block 2 is torn to expose the detection pad 17, and after a sample and/or alkaline buffer salt is added on the detection pad 17, the torn symbol display layer 2 is stuck on the sticky block 3 again. Detection line 171 appears on detection pad 17 when the substance being analyzed is present in the sample. Meanwhile, in an alkaline environment, ammonia gas is decomposed from ammonium salt in the sample or treated on the detection pad and released, the generated ammonia gas contacts with the indicator on the symbol display layer, the indication line 21 shows color, and forms a "+" or "-" symbol with the detection line 171, and the indication line 21 forms "+" with the detection line 171 as shown in fig. 15. .

In a more specific embodiment, the vertical flow detection device 10 includes a substrate pad, a gas generation pad, a reaction pad, a spacer pad 5, and an indicator pad 2. The gas generating pad and the reaction pad may be unified into a detection layer 1 according to the characteristics of different products. The function of the insulating mat 5 is to be air-permeable and water-impermeable. When a liquid sample is applied to the test device, the sample permeates through the substrate pad, the gas generant pad and the reaction pad. The substance to be detected present in the sample reacts with the substance pretreated on the reaction pad to form an obvious line. At the same time, ammonia gas is also released as the sample flows through the substrate pad and the gas generation pad. The ammonia gas permeates the isolation pad 5, so that the indicator changes color to form an obvious line. The line generated by the reaction of the substance to be detected forms a plus sign with the indicator line.

For example, saliva alcohol, the alcohol present in the sample reacts with the enzyme and substrate on the reaction pad to form a blue line. Meanwhile, when the sample flows through the substrate layer and the gas generation layer, ammonia gas is also released simultaneously. The ammonia gas permeates the isolation pad, so that the indicator changes color to form an obvious line. The line produced by the alcohol reaction forms a "+" with the indicator line.

Example 9: FIG. 13, FIG. 14 and FIG. 15 depict detection devices

In the embodiments shown in fig. 13 to 15, the detecting device 10 is also of a vertical flow detecting structure, and compared with the embodiment 8, the detecting layer 1 includes a gas generating pad 16 in addition to the bottom plate 11 and the detecting pad 17, and the gas generating pad 16 and the detecting pad 17 are sequentially adhered to the bottom plate 11. The gas generant pad 16 is treated with a gas generant material such as an ammonium salt or the like. The adhesive blocks 3 are respectively located at both ends of the detection pad 17, and the symbol display layer 2 is covered on the adhesive blocks 3, so that the symbol display layer 2 containing the indicator 21 is covered 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 to expose the detection pad 17, and after a sample and/or alkaline buffer salt is added to the detection pad 17, the torn symbol display layer 2 is stuck to the sticky block 3 again. Detection line 171 appears on detection pad 17 when the substance being analyzed is present in the sample. The sample continues to flow vertically downward and, after contacting the gas generant pad, contacts the ammonium salt disposed on the gas generant pad 16, which decomposes to produce a gas, which contacts the indicator 21 on the indicia display layer, with the indicator line appearing to form a "+" or "-" symbol with the test line.

In this embodiment, both the ammonium salt and the alkaline buffer salt can be treated on the gas generant pad 16 without being treated together. After the sample flows onto the gas generating pad, the alkaline buffer salt mixes with the ammonium salt as the liquid flows, generating gas.

Implementation 10: FIG. 17 depicts a detection device

In the embodiment shown in fig. 17, the detecting device 10 is located opposite to the detecting device 10 in fig. 13, that is, the sample pad 12, the gas generating pad 16, the detecting pad 17 and the symbol display layer 2 are arranged from top to bottom, and the sample pad 12, the gas generating pad 16 and the detecting pad 17 form the detecting layer 1. The sample is applied to the sample pad 12, and the sample flows into the gas generation pad 16 and the detection pad 17 in this order. After the generated gas contacts the symbol display layer 2, the indicator changes color, and the indicator is superposed with the detection line to display a symbol showing a detection result of "+" or "-". Wherein ammonium salts can be treated on sample pad 12, gas generant pad 16 or detection pad 17, and likewise, alkaline buffer salts can be treated on sample pad 12, gas generant pad 16 or detection pad 17. However, when the alkaline buffer salt and the ammonium salt are treated on the same pad, they are not treated at the same position, so that the reaction occurs before the hands are free, and gas is generated.

Example 11: the detection plate of fig. 18, 19 and 20

The detection plate 40 as shown in fig. 18 to 20 includes an upper plate 41, a lower plate 42, and the detection device 10. The test device 10 may be a lateral flow test strip or a vertical flow test strip. The materials and methods of treatment of the structure and components of the detecting unit 10 are also the same as those of examples 1 to 10.

FIG. 19 shows the sensing device 10 positioned within the base plate 41 and secured therein; the cover plate 42 is closed on the base plate 41, and the detection device 10 is closed between the cover plate 42 and the base plate 41 of the detection plate. The cover plate 42 is provided with a sample adding hole 45, and the position of the sample adding 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 adding hole 45 of the detection plate 40, and a sample can be directly added to the sample pad 12 through the sample adding hole 45. The cover plate 42 also has a window 43 for viewing the final test result.

In other embodiments, the window 43 is not covered with the transparent cover layer in advance, but the symbol display layer 2 is directly covered on the window 43, and the indicator 21 is coated on the symbol display layer at the position of the window and positioned on the detection line 171.

The detection plate 40 shown in fig. 20 includes an upper plate 41, a lower plate 42, and the detection device 10. The window 43 is covered with a transparent cover layer in advance, and the symbol display layer is directly adhered to the window 43, and the indicator 21 is positioned at the window and on the detection line 171.

The detection plate 40 shown in fig. 17 includes an upper plate 41, a lower plate 42, and the detection device 10. The detection device 10 comprises a sample detection layer 1 and a symbol display layer 2, wherein the symbol display layer is adhered on the sample detection layer and has a certain gap with the sample detection layer. The detection device 10 is placed in the base plate 41, and the cover plate 42 is closed on the base plate 41, so that the detection device 10 is closed between the cover plate 42 and the base plate 41 of the detection plate.

The detection plate 40 shown in fig. 18 includes an upper plate 41, a lower plate 42, and the detection device 10. The test device 10 is a vertical flow test strip, more specifically a test device selected from those shown in examples 6 to 8.

Example 12: substrate carrier for screening gas generation

The experimental process comprises the following steps:

a. the 1% NH4Cl substrate solution was treated on glass fiber, filter paper and polyester film, respectively, and dried for use.

b. The treated glass fibers, filter paper and absorbent rod were mounted on a sample pad of test paper (e.g., test paper in example 1), respectively. In comparison with a product without a substrate layer assembled.

c. The detection is carried out by using 100mIU/ml of hCG urine standard. Record the time of appearance of the indicator line and the color grade and detect line color.

The experimental results are as follows:

and (4) conclusion: when the substrate is processed on carriers made of different materials, the release speed of the substrate can be influenced, and the appearance time and the strength of the indicator line are influenced. In the comparative experiment, although no 1% NH4Cl substrate was added to the test strip. However, since the urine itself contains ammonium salt, when the urine contacts with the alkaline buffer solution of the test strip, ammonia gas is released to contact with the indicator, which means that the indicator changes color. And the color of the indicator line is lighter due to the lower concentration of ammonium salt in the urine. When the gas generating pad with the ammonium salt substrate is added on the detection test paper, the defects that the sample contains different ammonium salt concentrations and the color development of the indicator line is not uniform can be overcome. The uniform lines and the consistent color depth of the indicating lines of different sample detection results are ensured.

Example 13: indicating the influence of the Presence of a line on a detection line

The experimental process comprises the following steps:

a. the indicator-treated transparent sheet was assembled with a test device having a gas generating pad to form an hCG test strip (cross signal hCG test strip). An ordinary hCG test paper (without gas generating pad) was used as a control and tested simultaneously.

b. The detection is carried out by using 25mIU/ml and 100mIU/ml of hCG urine standard. Record the detection line color grade.

The experimental results are as follows:

detection reagent	25mIU/ml	100mIU/ml
			Common hCG reagent strip	Occurence detection line	Obvious detection line
Cross signal hCG reagent strip	Occurence detection line	Obvious detection line

And (4) conclusion: the existence of the indication line structure can not influence the strength of the detection line.

The detection device of the present invention can be applied to sample types including: liquid samples such as urine, blood, saliva, etc., or samples that can be processed into a liquid for testing, such as stool, etc.

The color-changing indicator can also be a redox indicator, and the color-changing indicator can generate color change when encountering an oxidizing substance or a reducing substance which is matched with reaction. For example, potassium dichromate itself is pale yellow and turns blue when exposed to ethanol gas.

Claims

1. A sample detection method capable of visually reading detection results comprises

Providing a detection device, wherein the detection device comprises a sample detection layer and a symbol display layer, the symbol display layer is positioned on the sample detection layer, a detection line is arranged on the detection layer, and an indicator is processed on the symbol display layer;

providing a gas generant capable of generating a gas that causes a color change in the indicator;

applying a fluid sample to the detection device, wherein the sample flows through the sample detection layer, the sample detection layer detects the sample, and the detection line presents a corresponding color according to the existence condition of the analyte in the sample;

mixing the substances in the gas generating agent to generate gas for changing the color of the indicator;

the gas contacts the indicator on the symbol display layer to change the indicator from a first color to a second color;

the indicator with the second color is matched with the detection line to form an identifiable symbol with a negative or positive detection result.

2. The method for detecting a sample according to claim 1, wherein the gas generating agent is selected from a basic buffer salt, or a combination of an ammonium salt and a basic buffer salt.

3. The method for detecting a sample according to claim 1, wherein the gas generating agent is entirely or partially disposed on the sample detection layer.

4. The method for detecting a specimen according to claim 1, wherein the indicator is selected from acid-base indicators.

5. The method for testing a specimen according to claim 1, wherein the indicator is selected from the group consisting of: p-nitrophenol, phenolphthalein, thymolphthalein, alpha-naphtholphthalein phenol red, cresol red, bromophenol blue, thymol blue, methyl orange, neutral red, methyl red, bromothymol blue, litmus, TCTB, bromocresol green, bromocresol purple, bromofenol blue.

6. The method for detecting a specimen according to claim 1, wherein the bringing of the gas into contact with the indicator on the symbol display layer to change the indicator from the first color to the second color is carried out by decomposing an ammonium salt in an alkaline environment to generate ammonia gas to change the indicator on the symbol display layer from the first color to the second color.

7. The method of claim 1, wherein the gas generating agent reacts and generates a gas that changes color of the indicator when the sample is applied to the test device.

8. The method of claim 1, wherein after applying the sample to the sample detection layer, a basic buffer salt is subsequently applied to the sample detection layer such that the basic buffer salt flows through the sample detection layer immediately following the fluid sample.

9. The sample detection method according to any one of claims 1 to 8, wherein the sample detection layer comprises a sample pad, a label pad, a gas generation pad, and a detection pad, which are connected in this order; treating an ammonium salt on a gas generation pad; the sample flows through the sample pad, the labeling pad, the gas generation pad and the detection pad in sequence, gas is generated on the gas generation pad, the generated gas is contacted with the indicator, and the sample is contacted with the detection line on the detection pad.

10. The method for detecting a specimen according to any one of claims 1 to 8, wherein when the detecting means exhibits only the second color of the indicator and does not exhibit the color of the detection line, the result of the detection is negative; when the detection device shows the second color of the indicator and the color of the detection line, the detection result is positive.

11. The method for detecting a specimen according to claim 10, wherein when the detection result is negative, the result of the detection means is displayed in a line shape in which the indicator color of the symbol display layer appears; when the detection result is positive, the result of the detection device shows that the I-shaped character presented by the indicator color of the symbol display layer is matched with the I-shaped character of the detection line of the sample detection layer to form a cross-shaped character.

12. A method of manufacturing a detection device, comprising:

(1) preparing a sample detection layer: providing a detection pad with a result display area, and adding a detection reagent reacting with the analyte to a detection line of the detection pad, wherein the detection line is in a corresponding color according to the existence condition of the analyte in the sample;

(2) preparation of the symbol display layer: providing a transparent or translucent carrier, preparing an indicator solution, and treating the indicator solution on the carrier, wherein the indicator changes from a first color to a second color after contacting with a gas capable of changing the color of the indicator;

(3) assembling the sample detection layer of step (1) and the symbol display layer of step (2) together and leaving said indicator out of contact with the result display area of the sample detection layer;

(4) providing a gas generating agent, wherein the gas generating agent is used for applying a sample to a detection device, substances in the gas generating agent are mixed with each other, and the gas which can cause the indicator to generate color change is generated;

the indicator of the second color can cooperate with the detection line to form an identifiable symbol that the detection result is negative or positive.

13. The method of claim 12, wherein some or all of the gas generant is disposed on the detection layer.

14. The method of claim 13, wherein the sample detection layer comprises a detection pad, a sample pad, and a label pad, the sample pad, the label pad, and the detection pad being sequentially connected to each other in a direction of liquid flow, the gas generating agent being disposed on at least one of the sample pad, the label pad, and the detection pad.

15. The method of claim 14, further comprising a gas generating pad mounted anywhere before the detection pad, the gas generating agent being added to the gas generating pad.

16. The method of claim 12, wherein the position and size of the indicator are set on the symbol display layer in correspondence with the position of the detection line of the result display area on the detection layer; the indicator is prepared into a solution with a certain concentration and is evenly coated on the symbol display layer according to the set position and size of the indicator.

17. The method of claim 12, wherein the indicator is selected from the group consisting of acid-base indicators.

18. The method of claim 12, wherein the indicator is selected from the group consisting of: p-nitrophenol, phenolphthalein, thymolphthalein, alpha-naphtholphthalein phenol red, cresol red, bromophenol blue, thymol blue, methyl orange, neutral red, methyl red, bromothymol blue, litmus, TCTB, bromocresol green, bromocresol purple, bromofenol blue.

19. The method of claim 12, wherein the gas generant is selected from a basic buffer salt, or a combination of an ammonium salt and a basic buffer salt.

20. The method of claim 19, wherein the ammonium salt is selected from NH₄Cl or ammonium carbonate, wherein the alkaline buffer is selected from Tris buffer, borax and NaCO₃、K3PO4。

21. The method of claim 20, wherein the sample detection layer is treated with ammonium chloride or ammonium carbonate formulated as a 1% solution.

22. The method of claim 15, wherein the gas generant pad is formed from a material selected from one of fiberglass, filter paper, or polyester film.

23. The method of claim 12 wherein the indicia displaying layer is selected from transparent or translucent water impermeable materials.

24. A method for visually reading detection results comprises providing a detection device, wherein the detection device comprises a sample detection layer and a symbol display layer; the symbol display layer is positioned on the sample detection layer; the detection layer is provided with a detection line, and the symbol display layer is processed with an indicator; after the indicator contacts the gas capable of changing color, the indicator changes from a first color to a second color; the gas is from a gas generating agent, the gas generating agent is formed by applying a sample to a detection device, substances in the gas generating agent are mixed with each other to generate gas for changing the color of the indicator; the indicator of the second color forms an identifiable symbol with the test result on the sample detection layer, wherein the test result is negative or positive.

25. The method of claim 24, wherein the gas generant is selected from a basic buffer salt, or a combination of an ammonium salt and a basic buffer salt.

26. The method of claim 24, wherein the gas generant is disposed in whole or in part on the sample detection layer.

27. The method of claim 24, wherein the indicator is selected from the group consisting of acid-base indicators.

28. The method of claim 27, wherein the acid-base indicator is selected from the group consisting of: p-nitrophenol, phenolphthalein, thymolphthalein, alpha-naphtholphthalein phenol red, cresol red, bromophenol blue, thymol blue, methyl orange, neutral red, methyl red, bromothymol blue, litmus, TCTB, bromocresol green, bromocresol purple, bromofenol blue.

29. The method of claim 24 wherein the indicator on the indicia displaying layer changes color from a first color to a second color by the generation of ammonia gas through the decomposition of an ammonium salt in an alkaline environment.

30. The method of claim 24, wherein the gas generating agent reacts and generates a gas that causes a color change in the indicator when the sample is applied to the detection device.

31. The method of any one of claims 24 to 30, wherein the sample detection layer comprises a sample pad, a label pad, a gas generation pad and a detection pad connected in series; treating an ammonium salt on a gas generation pad; the sample flows through the sample pad, the labeling pad, the gas generation pad and the detection pad in sequence, gas is generated on the gas generation pad, the generated gas is contacted with the indicator, and the sample is contacted with the detection line on the detection pad.

32. The method of claim 31, wherein when the detection device exhibits only the second color of the indicator and no color of the detection line is present, the detection result is negative; when the detection device shows the second color of the indicator and the color of the detection line, the detection result is positive.

33. The method of claim 32, wherein when the detection result is negative, the result of the detection device is displayed as a line in the color of the indicator of the symbol display layer; when the detection result is positive, the result of the detection device shows that the I-shaped character presented by the indicator color of the symbol display layer is matched with the I-shaped character of the detection line of the sample detection layer to form a cross-shaped character.

34. The method of any one of claims 24-30, wherein when the detection device exhibits only the second color of the indicator and no color of the detection line is present, the detection result is negative; when the detection device shows the second color of the indicator and the color of the detection line, the detection result is positive.

35. The method of claim 34, wherein when the detection result is negative, the result of the detection device is displayed as a line in the color of the indicator of the symbol display layer; when the detection result is positive, the result of the detection device shows that the I-shaped character presented by the indicator color of the symbol display layer is matched with the I-shaped character of the detection line of the sample detection layer to form a cross-shaped character.