Test paper and kit for detecting urea in body fluid

Abstract

The invention discloses test paper and a kit for detecting urea in body fluid, and the test paper comprises a base layer which comprises a near end and a far end transversely extending from the near end; the sampling area is arranged at the far end of the base layer and is used for absorbing body fluid to be detected; the reaction area is arranged on the base layer and is used for absorbing the body fluid in the sampling area so as to react by utilizing urease in the reaction area; the diffusion area is arranged on the base layer, is connected with the reaction area and is used for performing lateral chromatography on reactants generated in the reaction area from the far end to the near end; the color development area is arranged on the base layer, is isolated from the reaction area through the diffusion area and is used for absorbing reactants subjected to lateral chromatography by the diffusion area so as to carry out color development reaction by utilizing color development substances in the color development area, so that a detection result of the urea in the body fluid is displayed.

Description

Technical Field

[0001] The present application relates to the technical field of urea detection, and in particular to a test paper and a kit for detecting saliva urea. Background Art

[0002] At present, the methods used to detect whether urea is contained in liquid mainly include liquid reagent detection and test paper detection. Liquid reagent detection has the disadvantages of being difficult to store and carry, requiring special configuration of a placement stand and test tube, and inconvenient operation, while test paper detection has the advantages of being easy to carry and simple to operate.

[0003] In the related art, the test paper used to detect whether the liquid contains urea is mostly a vertical test paper. The vertical test paper includes carriers with reaction reagents stacked on each other, and the liquid sample to be tested flows from top to bottom through each reaction reagent layer, and finally displays the test result. For example, the urea nitrogen test paper disclosed in the invention patent CN106645675A is suitable for detecting whether urea nitrogen exists in the blood; another example is the urea test paper disclosed in the Chinese utility model patent CN210604396U. The urease test paper layer of this scheme is arranged on the upper layer of the phenol red chemical layer. If the liquid sample to be tested contains urea, the urease in the urease test paper layer will decompose the urea in the liquid sample to be tested to produce ammonia and carbon dioxide. Ammonia is easily soluble in water and is alkaline in aqueous solution. Under the action of gravity, it moves down to the phenol red chemical layer with the solution to produce a color change reaction. The above-mentioned vertical detection test strip is limited by the structural design, which results in that the reaction area and the color development area cannot be completely isolated, and has limitations such as short color development and reading time windows.

[0004] Therefore, the current detection accuracy of the test paper mainly depends on the accurate reading time / photographing time of the color development result. In other words, the current test paper needs to complete the reading / photographing of the color development result immediately after the reaction is completed, which limits the use of the test paper in professional scenarios such as laboratories and hospitals. Therefore, how to design a urea test paper that can extend the reading time window for individual users is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the shortcomings of the related art described above, the purpose of the present application is to provide a test strip and a kit for detecting urea in body fluids, a method and a system for detecting urea in body fluids, a computer device, a computer-readable storage medium, and a computer program product, so as to solve the technical problem of how to design a urea detection test strip that can extend the reading time window for easy use by individual users.

[0006] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present application provides a test paper for detecting urea in body fluids, comprising: a base layer, comprising a proximal end and a distal end extending laterally from the proximal end; a sampling area, arranged at the distal end of the base layer for absorbing the body fluid to be detected; a reaction area, arranged at the base layer for absorbing the body fluid in the sampling area to react with the urease in the reaction area; a diffusion area, arranged at the base layer and connected to the reaction area for laterally chromatographing the reactants produced in the reaction area from the distal end toward the proximal end; a color development area, arranged at the base layer and isolated from the reaction area by the diffusion area, for absorbing the reactants laterally chromatographed from the diffusion area to perform a color development reaction with the color development substance in the color development area, so as to display the detection result of urea in body fluids.

[0007] The second aspect of the present application provides a kit for detecting urea in body fluids, comprising: a shell having a built-in space, a first window located at the distal end of the shell, and a second window away from the first window; a base layer arranged in the built-in space; a sampling area arranged at the distal end of the base layer and used to absorb the body fluid to be detected through the first window; a reaction area arranged on the base layer and used to absorb the body fluid in the sampling area to react with the urease in the reaction area; a diffusion area arranged on the base layer and connected to the proximal end of the reaction area for laterally transferring the reactant in the reaction area; a color development area, arranged on the base layer corresponding to the second window and isolated from the reaction area by the diffusion area, used to absorb the reactant laterally transferred from the diffusion area to perform a color development reaction with the color development substance in the color development area, so as to display the detection result of urea in body fluids through the second window.

[0008] The third aspect of the present application provides a method for detecting urea in body fluids, comprising: obtaining a detection image obtained by photographing the test paper as described in the first aspect of the present application or the reagent kit as described in the second aspect of the present application using an image acquisition device; wherein the detection image is photographed within a reading time window after the test paper or the reagent kit absorbs the user's body fluid to be detected, and the detection image includes an image of a color development area; based on the detection image, determining color development data corresponding to the image of the color development area; based on the color development data and a standard curve corresponding to the test paper or the reagent kit, determining the urea concentration of the body fluid.

[0009] The fourth aspect of the present application provides a system for detecting urea in body fluids, comprising: an acquisition module, used to acquire a detection image obtained by photographing the test paper as described in the first aspect of the present application or the reagent kit as described in the second aspect of the present application using an image acquisition device; wherein the detection image is photographed within a reading time window after the test paper or the reagent kit absorbs the body fluid to be detected, and the detection image includes an image of a color development area; a color development data determination module, used to determine the color development data corresponding to the image of the color development area based on the detection image; and a concentration determination module, used to determine the urea concentration of the body fluid based on the color development data and a standard curve corresponding to the test paper or the reagent kit.

[0010] The fifth aspect of the present application provides a computer device, comprising: a storage device for storing at least one program; a processing device, connected to the storage device, for calling the at least one program from the storage device and executing it to implement the method for detecting urea in body fluids as described in the third aspect of the present application.

[0011] A sixth aspect of the present application provides a computer-readable storage medium storing at least one program, which, when called and executed by a processor of a computer, implements the method for detecting urea in body fluids as described in the third aspect of the present application.

[0012] A seventh aspect of the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the method for detecting urea in body fluids as described in the third aspect of the present application.

[0013] In summary, the present application provides a test paper and a kit for detecting urea in body fluids, a method and a system for detecting urea in body fluids, a computer device, a computer-readable storage medium, and a computer program product. The test paper arranges the sampling area, the reaction area, the diffusion area, and the color development area in sequence horizontally / laterally, so that the reaction area and the color development area are effectively separated by the diffusion area in the middle. The diffusion area can prevent the urease in the reaction area from entering the color development area, so that the catalytic reaction is terminated before the reaction liquid reaches the color development area, so as to improve the stability of the color development reaction in the color development area, and thus can extend the reading time window of the color development result of the test paper for the convenience of individual users. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The specific features of the present application are shown in the attached claims. The features and advantages of the invention involved in the present application can be better understood by referring to the exemplary embodiments and drawings described in detail below. The drawings are briefly described as follows:

[0015] Figure 1 Shown is a cross-sectional view of a test paper for detecting urea in body fluids in one embodiment of the present application.

[0016] Figure 2 Shown is a cross-sectional view of a test paper for detecting urea in body fluids in another embodiment of the present application.

[0017] Figure 3 The display is a standard curve diagram obtained based on analyzing the image obtained by photography in one embodiment of the present application.

[0018] Figure 4 Shown is a standard curve corresponding to the test paper prepared using a reaction reagent with a urease concentration of 65 kU / L in a pair of ratios of the present application.

[0019] Figure 5 The standard curve corresponding to the test paper prepared by the present application using the reaction reagent with the buffer concentration of 1.25mM and pH of 7.4 in a pair of ratios is shown.

[0020] Figure 6 Shown is a top view of a kit for detecting urea in body fluids in one embodiment of the present application.

[0021] Figure 7 Shown is a standard curve diagram of a test paper with a detection range of urea concentration of 5-30 mM in another embodiment of the present application.

[0022] Figure 8 Shown is a schematic flow chart of a method for detecting urea in body fluids in one embodiment of the present application.

[0023] Fig. 9 Shown is a structural block diagram of a system for detecting urea in body fluids in one embodiment of the present application. DETAILED DESCRIPTION

[0024] The following specific embodiments are used to illustrate the embodiments of the present application, and those familiar with the technology can easily understand the advantages of the present application and the technical effects that can be achieved by the content disclosed in this specification. In the following description, some embodiments can refer to the accompanying drawings. It should be understood that other embodiments without drawing drawings can also be used, and specific structures, parts or mechanisms, components and operational changes can be made without departing from the spirit and scope of the present application. The following detailed description should not be considered restrictive, and the scope of the embodiments of the present application is limited only by the claims published in the present application. The terms used here are only for describing specific embodiments and are not intended to limit the present application.

[0025] It should be understood that, although in some embodiments the term first, second or third etc. can be used to describe various elements or parameters in this article, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another element or parameter, and are not used to define the order, priority or importance of multiple elements. For example, the first window can be referred to as the second window, and similarly, the second window can be referred to as the first window, without departing from the scope of the various described embodiments, the first window and the second window are both describing a window, but unless the context clearly indicates otherwise, they are not the same window.

[0026] Furthermore, as used in this article, the singular forms "one", "an" and "the" are intended to also include plural forms, unless there is an indication to the contrary in the context. It should be further understood that the terms "comprising", "including" indicate the presence of the described features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. For example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment. In addition, the term "and / or" that may be used hereinafter, describes the association relationship of associated objects, indicating that three kinds of relationships may exist, for example, A and / or B, which can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / ", if not otherwise specified, generally represents that the associated objects before and after are a kind of "and / or" relationship. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two. Furthermore, the terms "or" and "and / or" used in this document are interpreted as inclusive, or mean any one or any combination. Exceptions to this definition will only occur when a combination of elements, functions, steps or operations are inherently mutually exclusive in some manner.

[0027] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by ordinary technicians in the field to which this application belongs. It will also be understood that the terms used herein should be interpreted as having the meaning consistent with their meaning in the context of this specification and the relevant field, and should not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0028] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element, layer or region to another element, layer or region as illustrated in the figure. It will be understood that these terms are intended to cover different device orientations other than the orientation depicted in the figure. In this application, the "vertical", "horizontal" and "parallel" are defined as: including the situation of ±10% on the basis of the standard definition. For example, vertical usually refers to an angle of 90° relative to a reference line, but in this application, vertical refers to the situation within 80° to 100°. Unless otherwise explicitly stated, comparative quantitative terms (such as "above" and "below") are intended to cover the concept of equality. As an example, "above" can not only mean "greater than" in a mathematical sense, but also "equal to".

[0029] In addition, the use of endpoints to limit the range of values ​​herein includes all values ​​contained in the range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Unless otherwise indicated, all numerical values ​​used to indicate the number of components, molecular weight, etc. in the specification and claims should be understood to be modified by the term "about" in all cases. Accordingly, unless otherwise indicated, the numerical parameters listed in this specification and claims are approximate values, which may vary depending on the desired properties that the present invention attempts to obtain. Each numerical parameter should be constructed at least according to the number of significant figures stated and by applying general rounding techniques, but this does not limit the basic principle that the scope of the claims is equivalent.

[0030] Although the numerical ranges and parameters setting forth the overall scope of the invention are approximations, the numerical values ​​set forth in the specific examples are provided as precisely as possible. However, all numerical values ​​necessarily include a certain range resulting from the standard deviation of their respective testing measurements.

[0031] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. When used herein, the singular forms "a", "an", and "the" are intended to also include the plural forms unless the context clearly indicates otherwise. It will also be understood that when used herein, the terms "comprise", "include", "include" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or increase of one or more other features, integers, steps, operations, elements, parts and / or combinations thereof.

[0032] As described in the background technology, the test strips used to detect whether the liquid contains urea are mostly vertical test strips. The area of ​​the reaction reagent carrier in the vertical test strips is relatively small, so a small amount of liquid sample is required. At the same time, there are certain requirements for the sample addition amount, which cannot exceed the maximum capacity that the reaction reagent carrier can accommodate. If the amount of liquid sample added is large, and the reaction reagent layer that reaches liquid saturation cannot absorb excess sample, these excess liquid samples will overflow from the test strip, polluting the environment or contacting the tester; in addition, the excess liquid will also gather on the reaction reagent layer to form droplets, which will not only affect the interpretation of the results by optical and other detection instruments, but also seriously pollute the detection instruments; it may also cause the color development area to be contaminated by the sample, the reaction liquid moves down to the color development area, resulting in the inability to terminate the color development, and the data read by the fixed reading time of the equipment deviates from the preset standard, resulting in inaccurate quantification and other problems.

[0033] To solve the above problems, the invention patent CN 102128918A adopts a liquid locking structure, which is intended to flow vertically into the reaction reagent layer to be absorbed when the liquid sample is added to the sample adding layer. When the reaction reagent layer is saturated with liquid, the liquid diffuses into the liquid locking component overlapped with the reaction reagent layer. Since the speed at which the liquid locking component absorbs liquid is less than or equal to the speed at which the reaction reagent layer absorbs liquid, when the excess liquid diffuses to the liquid locking component, the liquid on the reaction reagent layer is sufficient to carry out the relevant detection reaction, thereby not affecting the effective amount required for the detection reaction. When an excess sample is added, the excess sample is absorbed by the liquid locking component, so the excess sample will not form droplets overflowing from the test paper. However, this type of liquid locking structure has a complex process, requiring the liquid locking component to absorb liquid at a speed less than or equal to the speed at which the reaction reagent layer absorbs liquid, and has high material requirements for the liquid locking component, and adds a process to the test paper production process, making the test paper production process more complicated.

[0034] In addition, Ortho Clinical Diagnostics, an American company, launched a hospital-based urea test product MicroSlide is also a longitudinal dry chemical test paper, which uses highly precise quantitative sampling and timed reading to ensure the accuracy of the test. This type of test paper uses a precise sampling device to make the injection volume accurate to 5.5μL, and uses the matching dry biochemical analyzer to regularly collect color data and then analyze the urea content in the sample. This method has high requirements for test paper process and equipment accuracy. It is only suitable for hospital-side testing products and is not convenient for individual users, which limits the use scenarios of dry chemical test papers.

[0035] As mentioned above, the enzyme kinetic method is a method of quantitative or semi-quantitative testing by fixing the dosage and reaction time of the enzyme, and presenting different enzyme kinetic curves according to the different substrate concentrations, and then reflecting the change of the pH of the reaction system in the color development area, which is more common in chemical reagent kits and reagent trays, and the above-mentioned longitudinal test strips all use this method. The design of the longitudinal test strips, whether flowing from top to bottom or migrating from bottom to top, cannot achieve significant separation of the physical distance between the color development area and the reaction area at the design level. If the sample is to complete the enzyme kinetics quantification after passing through the reaction area, the reaction should be terminated in theory or the color development data should be read immediately. To terminate the reaction, it is usually necessary to change the pH value of the reaction system, which conflicts with the most commonly used pH indicator in the dry chemical test strips to indicate the reaction intensity. Therefore, most longitudinal dry chemical urea test strips cannot complete the action of terminating the reaction, so that their detection accuracy depends on the more accurate result collection timing.

[0036] Therefore, the detection accuracy of the current test paper mainly depends on the reading time / photographing time of the accurate color development result. Specifically, the test paper currently used to detect whether urea is contained in a liquid (such as blood) is arranged vertically between the reaction zone and the color development zone and the interval between the two is in the micrometer level, resulting in a shorter reading time window of the color development result, which is inconvenient for individual users to use, and limits the use scene of the dry chemical test paper. For example, the thickness of the carrier / substrate of each layer in the current longitudinal detection test paper is in the micrometer level, resulting in that even if the reaction zone and the color development zone are isolated in the longitudinal detection test paper, the interval between the reaction zone and the color development zone is maintained at the micrometer level due to the insufficient thickness of the isolated substrate, and then the stability of the color development in the color development zone is affected, resulting in a short reading time window.

[0037] In view of this, some embodiments provided in the present application disclose a test paper for detecting urea in body fluids, the test paper comprising a base layer, a sampling area, a reaction area, a diffusion area, and a color development area, the reaction area being used to absorb body fluids in the sampling area so as to react using urease in the reaction area, the diffusion area being used to laterally chromatograph the reactants produced in the reaction area from the distal end toward the proximal end, the color development area being isolated from the reaction area by the diffusion area and being used to absorb reactants laterally chromatographed by the diffusion area so as to perform a color development reaction using the color development substance in the color development area so as to display the detection result of urea in body fluids, the test paper of the present application uses the diffusion area so that the laterally arranged reaction area and the color development area are effectively separated by the diffusion area in the middle, the diffusion area can prevent urease in the reaction area from entering the color development area, and then the diffusion area can terminate the catalytic reaction of urease to improve the stability of the color development reaction in the color development area, thereby extending the reading time window of the color development result in the color development area for the convenience of individual users.

[0038] Wherein, the body fluid may be a body fluid of a human body or an animal body. Since the content of urea in the body fluid of an animal body or a human body is correlated with the content of urea in blood, the content of urea in blood can be calculated using the content of urea in the body fluid. The body fluid includes but is not limited to saliva, tears, sweat, urine, blood, serum, plasma, etc.

[0039] In one embodiment, the test paper uses saliva as the liquid to be tested, that is, the test paper of the present application is a test paper for detecting urea in saliva. Compared with collecting blood, serum, plasma, etc. for urea detection, saliva does not need to be collected in hospitals or laboratories, etc., which is convenient for individual users.

[0040] The test paper may also be called a test strip, a reagent strip, or a test strip, etc. The test paper may display the test result of urea in body fluid. Specifically, the test result may be represented by the color of the color-developing area in the test paper, and then the image of the color-developing area is acquired and analyzed to quantitatively calculate the urea content according to the image color of the color-developing area.

[0041] In one embodiment, see Figure 1 , which is a cross-sectional view of a test paper for detecting urea in body fluids in one embodiment of the present application, as shown in the figure, the test paper for detecting urea in body fluids comprises a base layer 1, a sampling area 2, a reaction area 3, a diffusion area 4, and a color development area 5. Specifically, the base layer 1 comprises a proximal end and a distal end extending laterally from the proximal end, the distal end of the base layer 1 is provided with a sampling area 2 for absorbing body fluids to be detected, the reaction area 3 is used to absorb body fluids in the sampling area 2 to react with urease in the reaction area 3, the diffusion area 4 is connected to the reaction area 3 and is used to laterally chromatograph the reactants produced in the reaction area 3 from the distal end toward the proximal end, the color development area 5 is isolated from the reaction area 3 by the diffusion area 4, and is used to absorb the reactants from the laterally chromatographed diffusion area 4 to perform a color development reaction with the color development substance in the color development area 5, so as to display the detection result of urea in body fluids.

[0042] In one embodiment, the base layer includes a proximal end and a distal end extending laterally from the proximal end. The proximal end and the distal end are opposite ends of the base layer, and the end of the base layer used to configure the sampling area is called the distal end of the base layer. Conversely, the end of the base layer away from the sampling area is called the proximal end of the base layer. Similarly, the side of each layer (sampling area, reaction area, diffusion area, and color development area) in the test paper that is relatively close to the proximal end of the base layer is also called the proximal end of each layer. Conversely, the side of each layer in the test paper that is relatively far from the proximal end of the base layer is called the distal end of each layer.

[0043] In one embodiment, the base layer is formed of a material having a water absorption rate lower than a preset water absorption rate to avoid absorbing liquids (body fluids, reactants) in each layer (sampling area, reaction area, diffusion area, and color development area). In one example, the preset water absorption rate is 1%, 2%, 3%, or 4%. For example, the base layer is a PVC (Polyvinyl chloride) board; further, the PVC board is a self-adhesive PVC board. For another example, the material of the base layer is polypropylene (pp) or polyethylene (pe), etc. It should be noted that the material of the base layer is not limited to the above examples. In other embodiments, any material with a water absorption rate lower than the preset water absorption rate can be used as the material of the base layer.

[0044] In one embodiment, in the test paper, the size of the base layer needs to at least meet the size required for the configuration of the sampling area, reaction area, diffusion area, and color development area. In one example, the width of the base layer is greater than or equal to the width of any layer in the sampling area, reaction area, diffusion area, and color development area. In one example, the length of the base layer is related to the length of each layer in the sampling area, reaction area, diffusion area, and color development area. For example, the length of the base layer needs to be greater than or equal to the sum of the lengths of each layer in the sampling area, reaction area, diffusion area, and color development area. In another example, when there is an overlapping area between adjacent layers (such as a reaction area and a diffusion area), the length of the base layer is related to the length of each layer in the sampling area, reaction area, diffusion area, and color development area and the size of the overlapping area of ​​the adjacent layers.

[0045] In one embodiment, if Figure 1 As shown, the sampling area 2 is arranged at the distal end of the base layer 1 for absorbing the body fluid to be detected.

[0046] In some embodiments, the sampling area 2 can be set at the distal end of the base layer 1 by gluing. For example, the base layer 1 is a PVC board with adhesive backing, and the sampling area 2 is glued to the adhesive backing side of the base layer 1. In other examples, the sampling area can also be fixed at the distal end of the base layer by fixing methods such as clamping and pressing.

[0047] In some embodiments, the user can drop the body fluid to be tested on the sampling area 2 of the test paper. Taking saliva as an example, the user can use a sampling tube, a dropper or other sampling container to directly take out the body fluid to be tested from the oral cavity or a container containing the body fluid to be tested and drop it on the sampling area 2, so that the sampling area 2 can absorb the body fluid to be tested. The user can also directly immerse the sampling area 2 in a container containing the body fluid to be tested so that the sampling area 2 can absorb the body fluid to be tested. It should be noted that the present application does not limit the way in which the sampling area absorbs the body fluid to be tested.

[0048] Taking the example of a user dropping a body fluid to be detected on the sampling area of ​​the test paper, in one example, the amount of the body fluid to be detected dropped on the sampling area is 50-200 μL. For example, the amount of the body fluid to be detected dropped on the sampling area is 50 μL, 60 μL, 70 μL, 80 μL, 90 μL, 100 μL, 110 μL, 120 μL, 130 μL, 140 μL, 150 μL, 160 μL, 170 μL, 180 μL, 190 μL, 200 μL.

[0049] In some embodiments, the material of the sampling area is a water-absorbing material, such as glass fiber membrane, polyester fiber membrane, absorbent paper, or filter paper.

[0050] In some embodiments, in the test paper, the length of the sampling area is between 15mm-30mm, and the width of the sampling area is between 3mm-5mm, that is, the length of the substrate of the sampling area is between 15mm-30mm, and the width of the substrate of the sampling area is between 3mm-5mm. For example, the length of the substrate of the sampling area is 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, or 30mm, and the width of the substrate of the sampling area is 3mm, 4mm, or 5mm.

[0051] It should be noted that the dimensions of each layer specified in the embodiments of the present application and the cover plate described later are not the dimensions during the manufacturing process (such as spraying or marking), but the dimensions of each layer and the cover plate in the final test paper. During the manufacturing process, it is only necessary to meet the size of the substrate required by each manufacturing process.

[0052] In one embodiment, if Figure 1 As shown, the reaction zone 3 is arranged on the base layer 1, and the reaction zone 3 is used to absorb the body fluid in the sampling zone 2 to react with the urease in the reaction zone 3. Specifically, the reaction zone 3 is arranged at the rear side / proximal end of the sampling zone 2, and then, the reaction zone 3 can absorb the body fluid in the sampling zone 2, and the reaction zone uses the urease in the reaction zone to react (catalytic reaction) with the urea in the body fluid to produce ammonia, and then obtain a reactant including ammonia ions (also referred to as a reaction solution).

[0053] In some embodiments, the reaction zone 3 can be set on the base layer 1 by gluing. For example, the base layer 1 is a PVC board with adhesive backing, and the reaction zone 3 is glued to the adhesive backing side of the base layer 1. In other examples, the reaction zone 3 can also be fixed on the base layer by fixing methods such as clamping and pressing.

[0054] Wherein, the reaction zone is formed by configuring the prefabricated reaction reagent on the substrate of the reaction zone. In some embodiments, the reaction reagent can be configured on the substrate of the reaction zone using a scribing process or a gold spraying process. For example, the reaction reagent is evenly scribed on the substrate of the reaction zone using a film-scribing gold spraying instrument. For another example, the reaction reagent is evenly sprayed on the substrate of the reaction zone using a film-scribing gold spraying instrument. Furthermore, after the reaction reagent is configured on the substrate of the reaction zone, it is necessary to perform a drying process, for example, drying in a 37°C blast drying oven for 60 minutes.

[0055] In one embodiment, the distribution density (also referred to as spraying amount or filming amount) of the reaction reagent disposed on the substrate in the reaction zone is 6-8 μL / cm 2 For example, the distribution density of the reaction reagents on the substrate in the reaction zone is 6 μL / cm 2 , 7μL / cm 2 , or 8μL / cm 2 .

[0056] In some embodiments, the substrate of the reaction zone is a water-absorbing material. For example, the substrate of the reaction zone is a nitrocellulose membrane, a PES membrane, a PVDF membrane, a cellulose acetate membrane, a mixed cellulose membrane, an NC membrane, a water-absorbing paper, or a filter paper. The nitrocellulose membrane may have a backing or may not have a backing.

[0057] In some embodiments, in the test paper, the length of the reaction zone is between 5 mm and 15 mm, and the width of the reaction zone is between 3 mm and 5 mm, that is, the length of the substrate of the reaction zone is between 5 mm and 15 mm, and the width of the substrate of the reaction zone is between 3 mm and 5 mm. For example, the length of the substrate of the reaction zone is 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm, and the width of the substrate of the reaction zone is 3 mm, 4 mm, or 5 mm.

[0058] In some embodiments, the reaction reagent includes a buffer, a protective agent, a metal ion chelator, a preservative, a surfactant, and urease; wherein the buffer is used to stabilize the pH value of the reaction reagent to prevent the influence of external factors on the pH value of the reaction reagent. The metal ion chelator is used to prevent the metal ions in the reaction reagent from affecting the catalytic reaction. The preservative is used to ensure that the reaction reagent remains stable during the validity period. The surfactant is used to promote the uniform distribution of the reaction reagent on the substrate of the reaction zone. The urease is used to catalyze the reaction with urea in the body fluid. The protective agent may include at least one of a protein protective agent, a carbohydrate protective agent, and a reducing protective agent. The protein protective agent is used to prevent the urease from denaturing or inactivating. The carbohydrate protective agent is used to stabilize the urease during the drying process to prevent the urease from becoming unstable due to the change of the hydration layer environment, or even crystallizing. The reducing protective agent is used to prevent oxidation reactions from occurring in the reaction reagent. Specifically, the reducing protective agent can provide a reducing environment to delay the oxidation of the disulfide bonds of the urease by oxygen in the air, thereby causing the three-dimensional structure of the urease to change. It should be noted that the effects of the various substances (buffer, protective agent, metal ion chelator, preservative, surfactant, and urease) in the reaction reagents described in the examples of the present application are the main effects of the various substances, and the various substances may also have other effects that they can play in the reaction reagents.

[0059] In one embodiment, the final concentration of urease in the reaction reagent is 10-50KU / L. For example, the final concentration of urease in the reaction reagent is 10KU / L, 15KU / L, 20KU / L, 25KU / L, 30KU / L, 35KU / L, 40KU / L, 45KU / L or 50KU / L. It should be noted that when the concentration of urease in the reaction reagent exceeds the range of 10-50KU / L, the accuracy of the test result (color development in the color development area) will be affected, and further, the linearity of the standard curve obtained by fitting based on the test result will be poor or the fitted standard curve will be nonlinear. For example, when the concentration of urease is greater than 50KU / L, the linearity of the standard curve is poor. Wherein, the standard curve is fitted according to the value of G / (R+G+B) of each image obtained by different urea concentrations and analysis. For example, the G / (R+G+B) value of an image is obtained based on the G / (R+G+B) value of each pixel in the image. For example, the G / (R+G+B) value of an image is the average value of the G / (R+G+B) values ​​of all pixels in the image.

[0060] In one embodiment, the final concentration of the buffer in the reaction reagent is 0.05-0.5 mM. For example, the final concentration of the buffer in the reaction reagent is 0.05 mM, 0.06 mM, 0.07 mM, 0.08 mM, 0.09 mM, 0.10 mM, 0.11 mM, 0.12 mM, 0.13 mM, 0.14 mM, 0.15 mM, 0.16 mM, 0.17 mM, 0.18 mM, 0.19 mM, 0.20 mM, 0.21 mM, 0.22 mM, 0.23 mM, 0.24 mM, 0.25 mM, 0.26 mM In one example, the buffer in the reaction reagent includes potassium dihydrogen phosphate and disodium hydrogen phosphate dihydrate.

[0061] In one embodiment, the final concentration of the carbohydrate protective agent in the reaction reagent is 2.5-50mM, for example, the final concentration of the carbohydrate protective agent is 2.5mM, 3.0mM, 3.5mM, 4.0mM, 4.5mM, 5.0mM, 5.5mM, 6.0mM, 6.5mM, 7.0mM, 7.5mM, 8.0mM, 8.5mM, 9.0mM, 9.5mM, 10.0mM, 10.5mM, 11.0mM, 11.5mM, 12.0mM, 12 .5mM, 13.0mM, 13.5mM, 14.0mM, 14.5mM, 15.0mM, 15.5mM, 16.0mM, 16.5mM, 17.0mM, 17.5mM, 18.0mM, 18.5mM , 19.0mM, 19.5mM, 20.0mM, 20.5mM, 21.0mM, 21.5mM, 22.0mM, 22.5mM, 23.0mM, 23.5mM, 24.0mM, 24.5mM, 25.0 mM, 25.5mM, 26.0mM, 26.5mM, 27.0mM, 27.5mM, 28.0mM, 28.5mM, 29.0mM, 29.5mM, 30.0mM, 30.5mM, 31.0mM, 3 1.5mM, 32.0mM, 32.5mM, 33.0mM, 33.5mM, 34.0mM, 34.5mM, 35.0mM, 35.5mM, 36.0mM, 36.5mM, 37.0mM, 37.5mM , 38.0mM, 38.5mM, 39.0mM, 39.5mM, 40.0mM, 40.5mM, 41.0mM, 41.5mM, 42.0mM, 42.5mM, 43.0mM, 43.5mM, 44.0mM, 44.5mM, 45.0mM, 45.5mM, 46.0mM, 46.5mM, 47.0mM, 47.5mM, 48.0mM, 48.5mM, 49.0mM, 49.5mM, or 50.0mM. In one example, the carbohydrate protective agent in the reaction reagent includes sucrose and / or trehalose.

[0062] In one embodiment, the final concentration of the protein protective agent in the reaction reagent is 1-5 μM, for example, the final concentration of the protein protective agent is 1.0 μM, 1.5 μM, 2.0 μM, 2.5 μM, 3.0 μM, 3.5 μM, 4.0 μM, 4.5 μM, or 5.0 μM. In one example, the protein protective agent in the reaction reagent includes bovine serum albumin.

[0063] In one embodiment, the final concentration of the reducing protective agent in the reaction reagent is 0.5-5mM. For example, the final concentration of the protein protective agent is 0.5mM, 0.6mM, 0.7mM, 0.8mM, 0.9mM, 1.0mM, 1.1mM, 1.2mM, 1.3mM, 1.4mM, 1.5mM, 1.6mM, 1.7mM, 1.8mM, 1.9mM, 2.0mM, 2.1mM, 2.2mM, 2.3mM , 2.4mM, 2.5mM, 2.6mM, 2.7mM, 2.8mM, 2.9mM, 3.0mM, 3.1mM, 3.2mM, 3.3mM, 3.4mM, 3.5mM, 3.6mM, 3.7mM, 3.8mM, 3.9mM, 4.0mM, 4.1mM, 4.2mM, 4.3mM, 4.4mM, 4.5mM, 4.6mM, 4.7mM, 4.8mM, 4.9mM, or 5.0mM. In one example, the reducing protective agent in the reaction reagent includes dithiothreitol.

[0064] In one embodiment, the final concentration of the metal ion chelator in the reaction reagent is 1-5 μM, for example, the final concentration of the metal ion chelator is 1.0 μM, 1.5 μM, 2.0 μM, 2.5 μM, 3.0 μM, 3.5 μM, 4.0 μM, 4.5 μM, or 5.0 μM. In one example, the metal ion chelator in the reaction reagent includes ethylenediaminetetraacetic acid.

[0065] In one embodiment, the final concentration of the preservative in the reaction reagent is 5-10 mM, for example, the final concentration of the preservative is 5.0 mM, 5.5 mM, 6.0 mM, 6.5 mM, 7.0 mM, 7.5 mM, 8.0 mM, 8.5 mM, 9.0 mM, 9.5 mM, 10.0 mM. In one example, the preservative in the reaction reagent includes sodium benzoate.

[0066] In one embodiment, the final concentration of the surfactant in the reaction reagent is 0.5-2 μM, for example, 0.5 μM, 0.6 μM, 0.7 μM, 0.8 μM, 0.9 μM, 1.0 μM, 1.1 μM, 1.2 μM, 1.3 μM, 1.4 μM, 1.5 μM, 1.6 μM, 1.7 μM, 1.8 μM, 1.9 μM, or 2.0 μM. In one example, the surfactant in the reaction reagent includes Triton-X-100.

[0067] In one embodiment, the pH value of the reaction reagent is maintained between 4.5 and 6.5. For example, the pH value of the reaction reagent is maintained at 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, or 6.5. In one embodiment, the pH adjusting agent for adjusting the reaction reagent to acidity can be hydrochloric acid, in other words, the reaction reagent also includes hydrochloric acid.

[0068] It should be noted that when the final concentration or pH value of the buffer or other substances in the reaction reagent exceeds the above range, it will also affect the accuracy of the test results, which will lead to poor linearity of the fitted standard curve or nonlinearity of the fitted curve. For example, when the final concentration of the buffer exceeds 0.5 mM, the standard curve fitted based on the test results will become nonlinear. For another example, when the pH value exceeds 6.5 (for example, 7.4), the fitted standard curve will become nonlinear.

[0069] In a specific embodiment, the reaction reagent is prepared by adding potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, trehalose, bovine serum albumin, ethylenediaminetetraacetic acid, dithiothreitol, and a preservative to water and fully dissolving them, adding a surfactant, adjusting the pH to acidic, and then adding urease; wherein the final concentrations of potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, trehalose, bovine serum albumin, ethylenediaminetetraacetic acid, dithiothreitol, preservative, surfactant, and urease in the reaction reagent are 0.05-0.5mM, 0.05-0.5mM, 2.5-50mM, 1-5μM, 1-5μM, 0.5-5mM, 5-10mM, 0.5-2μM, and 10-50KU / L, respectively.

[0070] In another specific embodiment, the reaction reagent is prepared by adding potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, sucrose, trehalose, bovine serum albumin, ethylenediaminetetraacetic acid, and a preservative to water and fully dissolving them, adding a surfactant, adjusting the pH to acidic, and then adding urease; wherein the final concentrations of potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, sucrose, trehalose, bovine serum albumin, ethylenediaminetetraacetic acid, preservative, surfactant, and urease in the reaction reagent are 0.05-0.5mM, 0.05-0.5mM, 2.5-50mM, 2.5-50mM, 1-5μM, 1-5μM, 5-10mM, 0.5-2μM, and 10-50KU / L, respectively. In one example, the final concentrations of potassium dihydrogen phosphate, sodium dihydrogen phosphate dihydrate, sucrose, trehalose, bovine serum albumin, ethylenediaminetetraacetic acid, preservatives, surfactants, and urease in the reaction reagents are 0.1 mM, 0.1 mM, 25 mM, 25 mM, 2.5 μM, 2.5 μM, 7.5 mM, 1 μM, and 30 KU / L, respectively.

[0071] In one embodiment, if Figure 1 As shown, the diffusion zone 4 is arranged on the base layer 1, and the diffusion zone 4 is connected to the reaction zone 3 for laterally chromatographing the reactants produced in the reaction zone from the distal end to the proximal end. Specifically, the diffusion zone 4 is arranged at the rear side / proximal end of the reaction zone 3, and is connected to the rear side / proximal end of the reaction zone 3. Then, the diffusion zone 4 can absorb the reactants in the reaction zone 3 and laterally chromatograph the reactants produced in the reaction zone 3 from the distal end of the diffusion zone 4 to the proximal end. For example, the diffusion zone 4 is arranged along Figure 1 The reactants produced in the reaction zone 3 are subjected to lateral chromatography in the direction of the lateral chromatography indicated by the middle arrow.

[0072] In some embodiments, the diffusion area 4 can be set on the base layer 1 by gluing. For example, the base layer 1 is a PVC board with adhesive backing, and the diffusion area 4 is glued to the adhesive backing side of the base layer 1. In other examples, the diffusion area 4 can also be fixed on the base layer by fixing methods such as clamping and pressing.

[0073] In one embodiment, the diffusion zone is formed by configuring a dispersing reagent on a substrate. In this way, the reactants can be uniformly and quickly diffused laterally in the diffusion zone to the color development zone to improve the accuracy and reliability of the detection. In one embodiment, the dispersing reagent can be configured on the substrate of the diffusion zone using a streaking process or a gold spraying process. For example, the dispersing reagent is uniformly streaked on the substrate of the diffusion zone using a film-scribing gold spraying instrument. For another example, the dispersing reagent is uniformly sprayed on the substrate of the diffusion zone using a film-scribing gold spraying instrument. In another embodiment, the diffusion zone is made by soaking the substrate in a bubble film tank containing the dispersing reagent. Furthermore, after the dispersing reagent is configured on the substrate of the diffusion zone, it is necessary to perform a drying process, for example, drying in a 37°C forced air drying oven for 2 hours.

[0074] In one embodiment, the distribution density (also referred to as the spraying amount or the filming amount) of the dispersing agent disposed on the substrate in the diffusion zone is 7-9 μL / cm 2 For example, the distribution density of the dispersed reagent configured on the substrate of the reaction zone is 7 μL / cm 2 , 8μL / cm 2 , or 9μL / cm 2 .

[0075] In some embodiments, the substrate of the diffusion zone is a water-absorbing material. For example, the substrate of the diffusion zone is a nitrocellulose membrane, a PES membrane, a PVDF membrane, a cellulose acetate membrane, a mixed cellulose membrane, an NC membrane, a water-absorbing paper, or a filter paper. The nitrocellulose membrane may have a backing or may not have a backing.

[0076] In some embodiments, in the test paper, the length of the diffusion zone is between 5 mm and 15 mm, and the width of the diffusion zone is between 3 mm and 5 mm, that is, the length of the substrate of the diffusion zone is between 5 mm and 15 mm, and the width of the substrate of the diffusion zone is between 3 mm and 5 mm. For example, the length of the substrate of the diffusion zone is 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm, and the width of the substrate of the diffusion zone is 3 mm, 4 mm, or 5 mm.

[0077] In some embodiments, the dispersing agent includes a dispersant. The dispersant is used to promote the dispersion and mixing of the reactants in the diffusion zone, so that a relatively uniform color development can be achieved in the color development zone, thereby avoiding the uneven pH distribution in the color development zone due to deviations in the reaction process, reducing reading errors, and improving the accuracy of detection. It should be noted that the role of the dispersant described in the embodiment of the present application is the main role of the dispersant, and the dispersant can also have other roles that it can play in the dispersing agent. The final concentration of the dispersant in the dispersing agent is 0.5%-1.5%, for example, the final concentration of the dispersant in the dispersing agent is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%; wherein, the dispersant is exemplified by sorbitol.

[0078] Furthermore, in one embodiment, the dispersing agent further comprises 0.9% sodium chloride. For example, the dispersing agent comprises 0.9% sodium chloride and 1.0% sorbitol.

[0079] In another embodiment, the dispersing agent may further include an enzyme inhibitor, for example, the dispersing agent includes a dispersant and an enzyme inhibitor, thereby accelerating diffusion while preventing the residual urease in the reactant from continuing to catalyze the reaction. The final concentration of the enzyme inhibitor in the dispersing agent is 0.01-0.05 mM. In a specific embodiment, the dispersing agent is prepared by adding sorbitol to water until the final concentration of sorbitol is 0.5%-1.5%. For example, the final concentration of sorbitol is 1%.

[0080] In one embodiment, if Figure 1 As shown, the color development area 5 is arranged on the base layer 1 and is isolated from the reaction area 3 by the diffusion area 4. The color development area 5 is used to absorb the reactants from the lateral chromatography of the diffusion area 4 to perform a color development reaction using the color development substance in the color development area 5, so as to display the detection result of body fluid urea. Specifically, the color development area 5 is arranged at the rear side / proximal end of the diffusion area 4, and is isolated from the reaction area 3 by the diffusion area 4. The color development area 5 performs a color development reaction with the reactants using the color development substance to display the detection result of body fluid urea; in this way, the color development area can improve the stability of the detection result, that is, the stability of the color development, by being isolated from the reaction area, and prolong the reading time window of the detection result.

[0081] In one embodiment, the pH value of the reactant changes with the concentration of the ammonium ions contained in the reactant, and then the color-developing substance can present different colors when performing a color development reaction, and then the color-developing area of ​​different colors is the test result. In other words, the test result can be represented by the color of the color-developing area in the test paper; further, by obtaining an image of the color-developing area, the image is color-analyzed to quantitatively calculate the urea concentration / ammonia ion concentration through the image color of the color-developing area. For example, the G / (R+G+B) value of the image can be determined through the image of the color-developing area, and then the urea concentration / content can be determined through the G / (R+G+B) value of the image and the standard curve.

[0082] In some embodiments, the color development area 5 can be set on the base layer 1 by gluing. For example, the base layer 1 is a PVC board with adhesive backing, and the color development area 5 is glued to the adhesive backing side of the base layer 1. In other examples, the color development area 5 can also be fixed on the base layer by fixing methods such as clipping and pressing.

[0083] Wherein, the color development area is formed by configuring a prefabricated color development reagent on the substrate of the color development area. In some embodiments, the color development reagent can be configured on the substrate of the color development area using a streaking process or a gold spraying process. For example, the color development reagent is evenly streaked on the substrate of the color development area using a film streaking gold spraying instrument. For another example, the color development reagent is evenly sprayed on the substrate of the color development area using a film streaking gold spraying instrument. Furthermore, after the color development reagent is configured on the substrate of the color development area, it is necessary to perform a drying process, for example, drying in a 37°C forced air drying oven for 60 minutes.

[0084] In one embodiment, the distribution density (also referred to as the spraying amount or the filming amount) of the color developing reagent disposed on the substrate of the color developing area is 8-10 μL / cm 2 For example, the distribution density of the color developing reagent configured on the substrate of the color developing area is 8 μL / cm 2 , 9μL / cm 2 , or 10μL / cm 2 .

[0085] In some embodiments, the substrate of the color development area is a water-absorbing material. For example, the substrate of the color development area includes NC membrane, PES membrane, PVDF membrane, cellulose acetate membrane, mixed cellulose membrane, water-absorbing paper, or filter paper.

[0086] In some embodiments, in the test paper, the length of the color development zone is between 5mm-15mm, and the width of the color development zone is between 3mm-5mm, that is, the length of the substrate of the color development zone is between 5mm-15mm, and the width of the substrate of the color development zone is between 3mm-5mm. For example, the length of the substrate of the color development zone is 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, or 15mm, and the width of the substrate of the color development zone is 3mm, 4mm, or 5mm.

[0087] In some embodiments, the color developing reagent includes a buffer, a color developing substance, a preservative, and a surfactant. The buffer is used to stabilize the pH value of the color developing reagent to prevent the influence of external factors on the pH value of the color developing reagent, and the preservative is used to ensure that the color developing reagent remains stable within the validity period. The surfactant is used to promote the uniform distribution of the color developing reagent on the substrate of the color developing area. The color developing substance is used to generate a color development reaction to obtain the detection result.

[0088] In one embodiment, the final concentration of the buffer in the colorimetric reagent is 0.05-0.5 mM. For example, the final concentration of the buffer in the colorimetric reagent is 0.05 mM, 0.06 mM, 0.07 mM, 0.08 mM, 0.09 mM, 0.10 mM, 0.11 mM, 0.12 mM, 0.13 mM, 0.14 mM, 0.15 mM, 0.16 mM, 0.17 mM, 0.18 mM, 0.19 mM, 0.20 mM, 0.21 mM, 0.22 mM, 0.23 mM, 0.24 mM, 0.25 mM, 0.26 mM. In one example, the buffer in the color developing reagent includes citric acid monohydrate and sodium citrate dihydrate.

[0089] In one embodiment, the final concentration of the preservative in the colorimetric reagent is 5-10 mM, for example, the final concentration of the preservative in the colorimetric reagent is 5.0 mM, 5.5 mM, 6.0 mM, 6.5 mM, 7.0 mM, 7.5 mM, 8.0 mM, 8.5 mM, 9.0 mM, 9.5 mM, 10.0 mM. In one example, the preservative in the colorimetric reagent includes sodium benzoate.

[0090] In one embodiment, the final concentration of the surfactant in the color developing reagent is 0.5-2 μM, for example, the final concentration of the surfactant in the color developing reagent is 0.5 μM, 0.6 μM, 0.7 μM, 0.8 μM, 0.9 μM, 1.0 μM, 1.1 μM, 1.2 μM, 1.3 μM, 1.4 μM, 1.5 μM, 1.6 μM, 1.7 μM, 1.8 μM, 1.9 μM, or 2.0 μM. In one example, the surfactant in the reaction reagent includes Triton-X-100.

[0091] In one embodiment, the final concentration of the color developing substance in the color developing reagent is 1-5mM, and the final concentration of the color developing substance in the color developing reagent is 1mM, 1.5mM, 2.0mM, 2.5mM, 3.0mM, 3.5mM, 4.0mM, 4.5mM, or 5.0mM. In one example, the color developing substance in the color developing reagent is phenol red. In other examples, the display substance can also be other pH indicators suitable for detecting urea.

[0092] In one embodiment, the pH value of the color developing reagent is maintained between 2.5 and 5.5. For example, the pH value of the color developing reagent is maintained at 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, or 5.5. In one embodiment, the pH adjusting agent for adjusting the color developing reagent to acidity can be hydrochloric acid, in other words, the color developing reagent also includes hydrochloric acid.

[0093] It should be noted that when the final concentration or pH value of the buffer solution or other substances in the color developing reagent exceeds the above range, it will also affect the accuracy of the test results, thereby causing the linearity of the fitted standard curve to be poor or the fitted curve to be nonlinear.

[0094] In a specific embodiment, the color reagent is prepared by adding citric acid monohydrate, sodium citric acid dihydrate, phenol red, and a preservative to water and fully dissolving them, adding a surfactant, and adjusting the pH to acidic; wherein the final concentrations of citric acid monohydrate, sodium citric acid dihydrate, phenol red, a preservative, and a surfactant in the color reagent are 0.05-0.5mM, 0.05-0.5mM, 1-5mM, 5-10mM, and 0.5-2μM, respectively. In an example, the final concentrations of citric acid monohydrate, sodium citric acid dihydrate, phenol red, a preservative (such as sodium benzoate), and a surfactant (such as Triton X 100) in the color reagent are 0.1mM, 0.1mM, 2.5mM, 7.5mM, and 1μM, respectively.

[0095] The color development zone described in the present application is not provided with a water-absorbing material on the back side. Due to the size limitation of the color development zone, the water holding capacity of the color development zone is limited. After the color development zone is fully absorbed by the reactants, the reactants in the reaction zone lose the power to continue to migrate laterally through capillary action, thereby physically isolating the path for the reactants generated in the reaction zone to continuously migrate to the color development zone, objectively terminating the color development reaction, and then making the detection results of the color development zone stably displayed after the reaction is completed, without continuous color change, further extending the reading time window.

[0096] In one embodiment, the test paper further includes a protective layer covering any one or more of the reaction zone, diffusion zone, and color development zone. The protective layer is used to control the evaporation of water and the escape of ammonia. Specifically, the concentration of ammonium ions in the reactants is a direct factor affecting the color intensity of the color development zone. The evaporation of water and the escape of ammonium ions in the form of ammonia will cause changes in the concentration of ammonium ions in the reaction solution, thereby affecting the color intensity of the color development zone. Furthermore, the protective layer can also be used to fix reagents. In some examples, the test paper includes a protective layer covering any one of the reaction zone, diffusion zone, and color development zone. In other examples, the test paper includes a protective layer covering any two of the reaction zone, diffusion zone, and color development zone; for example, Figure 1 As shown, the test paper includes a protective layer 6 covering the reaction area 3 and the color development area 5, so that the evaporation of water and the escape of ammonia gas in the reaction area 3 and the color development area 5 can be avoided, and the fixing of the reaction reagent by the protective layer 6 can prevent the reaction reagent from migrating to the diffusion area 4 or even the color development area 5 and affecting the termination of the reaction. The fixing of the color development reagent by the protective layer 6 can ensure that the color development reagent stably develops color in a certain area without migrating with the liquid, thereby ensuring the stability of the sampling of the color development result, and thus ensuring the accuracy and stability of the detection. Further, in some other embodiments, the test paper includes a protective layer covering the reaction area, the diffusion area, and the color development area, so that the evaporation of water and the escape of ammonia gas in the whole process of the reactant diffusing from the reaction area to the color development area can be avoided, further improving the accuracy of the detection.

[0097] In the embodiment where the body fluid is saliva, the content of urea in saliva is relatively low, and the accuracy of saliva urea detection can be improved by providing the protective layer in any of the above embodiments in the test paper.

[0098] In one embodiment, the protective layer is formed by configuring the protective reagent on any one or more of the reaction zone, diffusion zone, and color development zone. Taking the test paper including a protective layer covering the reaction zone and the color development zone as an example, the formation of the protective layer is explained. First, the reaction reagent is configured on the substrate of the reaction zone and the color development reagent is configured on the substrate of the color development zone, and then the protective reagent is configured in the area of ​​the reaction zone and the color development zone. It should be noted that when configuring the protective reagent, the size of the reaction layer and the color development layer can be larger than the size specified in the above embodiment, and the size of the color development zone and the reaction zone in the test paper only needs to meet the above definition. Furthermore, after the protective reagent is configured on the reaction zone and the color development zone, it is necessary to perform a drying process, for example, drying in a 37°C forced air drying oven for 60 minutes.

[0099] In one embodiment, the distribution density (also referred to as spraying amount or filming amount) of the protective reagent configured in the reaction zone, diffusion zone, and / or color development zone is 14-16 μL / cm 2 For example, the distribution density of the protective reagent configured in the reaction zone, diffusion zone, and / or color development zone is 14 μL / cm 2 , 15μL / cm 2 , or 17μL / cm 2 .

[0100] In one embodiment, the protective reagent includes a buffer and a film-forming agent. The buffer is used to stabilize the pH value of the reaction reagent to prevent the influence of external factors on the pH value of the reaction reagent. The film-forming agent is used to form a protective film on the surface of the reaction area and the color development area.

[0101] In one embodiment, the final concentration of the buffer in the protective reagent is 0.05-0.5 mM. For example, the final concentration of the buffer in the protective reagent is 0.05 mM, 0.06 mM, 0.07 mM, 0.08 mM, 0.09 mM, 0.10 mM, 0.11 mM, 0.12 mM, 0.13 mM, 0.14 mM, 0.15 mM, 0.16 mM, 0.17 mM, 0.18 mM, 0.19 mM, 0.20 mM, 0.21 mM, 0.22 mM, 0.23 mM, 0.24 mM, 0.25 mM, 0.26 mM 47mM, 0.48mM, 0.49mM, or 0.50mM. In one example, the buffer in the protective reagent includes potassium dihydrogen phosphate and disodium hydrogen phosphate dihydrate.

[0102] In one embodiment, the final concentration of the film-forming agent in the protective agent is 0.5%-1.5%, for example, the final concentration of the film-forming agent in the protective agent is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%. In one example, the film-forming agent in the protective agent includes chitosan, chitosan quaternary ammonium salt, carboxymethyl chitosan, starch, modified starch, chondroitin sulfate, keratin, silk protein, cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, konjac glucomannan, dextran, alginate, carrageenan, xanthan gum, gum arabic, poloxamer, polyethylene glycol, polylactic acid, polylysine, polylactide, polyvinyl alcohol, polyacrylonitrile, or polyvinyl pyrrolidone.

[0103] In one embodiment, the pH value of the protective agent is maintained between 4.5 and 6.5. For example, the pH value of the protective agent is maintained at 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, or 6.5. In one embodiment, the pH adjusting agent for adjusting the protective agent to acidity can be hydrochloric acid, in other words, the protective agent also includes hydrochloric acid.

[0104] In a specific embodiment, the protective agent is prepared by adding potassium dihydrogen phosphate and disodium hydrogen phosphate dihydrate to water, fully dissolving them, adjusting the pH to acidic, and then adding a film-forming agent; wherein the final concentrations of potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, and the film-forming agent in the protective agent are 0.05-0.5mM, 0.05-0.5mM, and 0.5%-1.5%, respectively. In an example, the final concentrations of potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, and the film-forming agent in the protective agent are 0.07mM, 0.03mM, and 1%, respectively.

[0105] It should be noted that when the final concentration or pH value of the buffer solution or other substances in the protective reagent exceeds the above range, it will also affect the accuracy of the test results, thereby causing the linearity of the fitted standard curve to be poor or the fitted curve to be nonlinear.

[0106] See also Figure 1 , the test paper for detecting urea in body fluids also includes a cover plate 7, and the cover plate 7 is arranged at the proximal end of the color development area 5. For example, the cover plate 7 is directly adhered to the base layer 1. For another example, the cover plate 7 is fixed to the proximal end of the color development area 5 by fixing methods such as clamping and pressing. In this embodiment, the cover plate 7 is made of non-water-absorbing material. Non-water-absorbing material refers to a material whose water absorption rate is lower than the preset water absorption rate. For example, the cover plate 7 is made of PVC. By setting the cover plate 7 to a non-water-absorbing material, it is possible to prevent the color development area 5 from absorbing too much reactant, so as to improve the stability of color development and the accuracy of detection.

[0107] Further, if Figure 1 As shown, the distal end of the cover plate 7 and the proximal end of the color development area 5 also have an overlapping area. The length of the overlapping area is 1-2 mm, for example.

[0108] In some embodiments, in the test paper, the length of the cover is between 15mm-30mm, and the width of the cover is between 3mm-5mm. For example, the length of the cover is 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, or 30mm, and the width of the cover is 3mm, 4mm, or 5mm.

[0109] The reaction area, diffusion area, and color development area of ​​the test paper for detecting urea in body fluid described in the present application can be as follows Figure 1 The shown ones are formed on different substrates and connected in sequence, or they can be formed in different regions on the same substrate. Adjacent reaction regions and diffusion regions, or adjacent diffusion regions and color development regions can be formed in different regions on the same substrate.

[0110] In one embodiment, if Figure 1 As shown, the diffusion zone 4, the reaction zone 3, and the color development zone 5 are formed on different substrates, and the diffusion zone 4 is located between the reaction zone 3 and the color development zone 5 to spatially isolate the reaction zone 3 and the color development zone 5; in other words, the substrates of the diffusion zone 4, the reaction zone 3, and the color development zone 5 are independent three-section substrates, and the diffusion zone 4 is arranged in the middle of the reaction zone 3 and the color development zone 5 to spatially isolate the reaction zone 3 and the color development zone 5. In this embodiment, the sampling zone 2, the reaction zone 3, the diffusion zone 4, and the color development zone 5 can be adhered to the base layer 1 through the adhesive on the base layer 1. The adhesive is exemplified by the adhesive on the base layer 1.

[0111] Further, if Figure 1 As shown, the sampling area 2, the reaction area 3, the diffusion area 4, and the color development area 5 are arranged in sequence on the base layer 1 to form a liquid passage through a plurality of overlapping areas, so that the test paper can perform lateral chromatography on the reactant. In one example, the length of the overlapping area is 1-2 mm. For example. The length of the overlapping area is 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, or 3.0 mm.

[0112] In another embodiment, see Figure 2 , which is a cross-sectional view of a test paper for detecting urea in body fluids in another embodiment of the present application. As shown in the figure, the reaction area 3, the diffusion area 4, and the color development area 5 are sequentially formed on different areas of the same substrate. Specifically, the reaction area 3 is formed in the distal area of ​​a substrate, the color development area 5 is formed in the proximal area of ​​the substrate, and the diffusion area 4 is formed in the middle area of ​​the substrate. For example, the distal area, the middle area, and the proximal area on a substrate are respectively configured with reaction reagents, dispersion reagents, and color development reagents to form the reaction area 3, the diffusion area 4, and the color development area 5. Among them, the distal area, the middle area, and the proximal area are sequentially connected. In this embodiment, the reaction area 3, the diffusion area 4, and the color development area 5 as a whole and the sampling area 2 can be pasted on the base layer 1 through the adhesive on the base layer 1. Further, in one embodiment, the proximal end of the sampling area 2 and the distal end of the reaction area 3 have an overlapping area. The length of the overlapping area is 1-2mm for example.

[0113] In another embodiment, the reaction zone and the diffusion zone are formed on different areas on the same substrate, and the color development zone is formed on another independent substrate; further, the proximal end of the sampling zone and the distal end of the reaction zone have an overlapping area, and the proximal end of the diffusion zone and the distal end of the color development zone have an overlapping area.

[0114] In another embodiment, the diffusion zone and the color development zone are formed on different areas on the same substrate, and the reaction zone is formed on another independent substrate; further, the proximal end of the sampling zone and the distal end of the reaction zone have an overlapping area, and the proximal end of the reaction zone and the distal end of the diffusion zone have an overlapping area.

[0115] Based on the description of the above embodiments, in some embodiments, the present application provides methods for preparing two test papers of Embodiment 1 and Embodiment 2 to prepare two test papers with different structures for detecting urea in body fluids.

[0116] Embodiment 1:

[0117] The first step is to weigh 1.36 mg potassium dihydrogen phosphate, 1.78 mg sodium dihydrogen phosphate dihydrate, 8.56 g trehalose, 250 mg bovine serum albumin, 10 mg ethylenediaminetetraacetic acid, 15.43 mg dithiothreitol, and 100 mg sodium benzoate and dissolve them in ultrapure water. After fully dissolved, add 150 μL of Triton X 100, add hydrochloric acid to adjust the pH value of the solution to 6.5 and dilute to 100 mL, dissolve urease in the above solution to ensure that the final concentration of urease is 15 kU / L, and prepare the reaction reagent; weigh 1 g sorbitol and dissolve it in ultrapure water, and dilute to 100 mL after fully dissolved to prepare a dispersing reagent; weigh 1.68 mg citric acid monohydrate, 0.59 mg sodium citric acid dihydrate, 0.1 g phenol red, and 100 mg sodium benzoate and dissolve them in ultrapure water. After fully dissolved, add 150 μL of Triton X 100, add hydrochloric acid to adjust the pH value of the solution to 3.5 and dilute to 100 mL to prepare a colorimetric reagent; weigh 0.95 mg of potassium dihydrogen phosphate, 0.53 mg of disodium hydrogen phosphate dihydrate, and 1 g of chitosan and dissolve them in ultrapure water. After fully dissolved, add hydrochloric acid to adjust the pH value of the solution to 6.5 and dilute to 100 mL to prepare a protective reagent.

[0118] In the second step, the prepared reaction reagent is evenly sprayed on the substrate (nitrocellulose membrane) in the reaction zone at a spraying amount of 7 μL / cm2 using a film-scratch gold spraying instrument, and the membrane is placed in a 37°C air drying oven for drying for 60 minutes; the substrate (nitrocellulose membrane) in the diffusion zone is placed in a bubble film tank containing 60 mL of a dispersing reagent and soaked for 5 minutes, then taken out and placed in a 37°C air drying oven for drying for 2 hours; the prepared color development reagent is evenly sprayed on the substrate (nitrocellulose membrane) in the color development zone at a spraying amount of 9 μL / cm2 using a film-scratch gold spraying instrument, and the membrane is placed in a 37°C air drying oven for drying for 60 minutes; then, after the nitrocellulose membrane sprayed with the reaction reagent and the color development reagent is dried, the prepared protection reagent is evenly sprayed on the reaction zone and the color development zone respectively at a spraying amount of 15 μL / cm2 using a film-scratch gold spraying instrument, and the membrane is placed in a 37°C air drying oven for drying for 60 minutes.

[0119] In the third step, the 18 mm long sampling area (glass fiber membrane), the 7 mm long reaction area, the 8 mm long diffusion area, the 7 mm long color development area, and the 15 mm long cover plate are overlapped and pasted on the PVC board in sequence. After pasting, they are cut into 4 mm wide test papers for detecting urea in body fluids. The structure of the test paper prepared in this embodiment is as follows Figure 1 shown.

[0120] Embodiment 2:

[0121] The first step is to weigh 1.36 mg potassium dihydrogen phosphate, 1.78 mg sodium dihydrogen phosphate dihydrate, 8.56 g trehalose, 250 mg bovine serum albumin, 10 mg ethylenediaminetetraacetic acid, 15.43 mg dithiothreitol, and 100 mg sodium benzoate and dissolve them in ultrapure water. After fully dissolved, add 150 μL of Triton X 100, add hydrochloric acid to adjust the pH value of the solution to 6.5 and dilute to 100 mL, dissolve urease in the above solution to ensure that the final concentration of urease is 15 kU / L, and prepare the reaction reagent; weigh 1 g sorbitol and dissolve it in ultrapure water, and dilute to 100 mL after fully dissolved to prepare a dispersing reagent; weigh 1.68 mg citric acid monohydrate, 0.59 mg sodium citric acid dihydrate, 0.1 g phenol red, and 100 mg sodium benzoate and dissolve them in ultrapure water. After fully dissolved, add 150 μL of Triton X 100, add hydrochloric acid to adjust the pH value of the solution to 3.5 and dilute to 100 mL to prepare a colorimetric reagent; weigh 0.95 mg of potassium dihydrogen phosphate, 0.53 mg of disodium hydrogen phosphate dihydrate, and 1 g of chitosan and dissolve them in ultrapure water. After fully dissolved, add hydrochloric acid to adjust the pH value of the solution to 6.5 and dilute to 100 mL to prepare a protective reagent.

[0122] In the second step, a piece of NC film is used as the substrate of the reaction area, diffusion area, and color development area, and the prepared reaction reagent, dispersion reagent, and color development reagent are respectively drawn in the corresponding area with a slip amount of 7μL / cm, 8μL / cm, and 9μL / cm by a film-spraying gold spraying instrument. The drawing area of ​​the reaction reagent is the first 7mm, the drawing area of ​​the dispersion reagent is connected to the drawing area of ​​the reaction reagent and the length is 8mm, and the drawing area of ​​the color development reagent is connected to the drawing area of ​​the dispersion reagent and the length is 7mm. After each drawing is completed, it is dried in a 37℃ blast drying oven for 60min; after drying, the prepared protective reagent is sprayed evenly on the reaction area and the color development area with a spray amount of 15μL / cm2 by a film-spraying gold spraying instrument, and placed in a 37℃ blast drying oven for 60min.

[0123] In the third step, a 15 mm long sampling area (glass fiber membrane), a 22 mm long NC membrane, and a 15 mm long cover plate are overlapped and pasted on the PVC plate in sequence. After pasting, the test paper is cut into 4 mm wide test paper for detecting urea in body fluids. The structure of the test paper prepared in this embodiment is as follows: Figure 2 shown.

[0124] The test paper for detecting urea in body fluids corresponding to the preparation method of Example 1 was tested, and 6 portions of saliva with urea concentrations of 2mM, 4mM, 6mM, 8mM, 10mM, and 12mM were taken as samples, and the amount of each portion of saliva was 100μL. 6 portions of 100μL of saliva were dropped on the sampling areas of 6 test papers respectively, and reacted at room temperature. The color development of the color development area remained stable within the time window of 5-10min after the sample was added, and the color development area of ​​the saliva of the 6 test papers was photographed at 5min. After analyzing the image, the standard curve was fitted according to the G / (R+G+B) value of the image obtained by different urea concentrations and analysis, and the standard curve obtained by fitting is shown in the figure below. Figure 3 As shown, according to Figure 3 It can be seen that the standard deviation of the fitted standard curve is 0.9925, which has good linearity. In other words, the test paper in this embodiment has high detection accuracy.

[0125] Further, five test strips with urea concentrations of 2 mM, 4 mM, 6 mM, 8 mM and 10 mM in the above embodiment were taken, and the color development areas of the saliva of the five test strips were photographed at 5 min, 8 min, and 10 min, respectively, and the G / (R+G+B) value of the image corresponding to each test strip was analyzed. The G / (R+G+B) values ​​of the images at different times with different urea concentrations are shown in the following table:

[0126]

[0127] According to the table, at 5min, 8min, and 10min, the values ​​of G / (R+G+B) corresponding to each urea concentration remain relatively stable. Figure 3 It can be seen that the test paper of the present application has both high detection accuracy and a long reading time window, thereby meeting the sampling time requirements of users' self-testing.

[0128] It should be noted that the stable color development time of 5-10 minutes shown in the table should not be understood as a limitation on the stable color development time of the test paper of the present application. In the laboratory, the test paper for detecting urea in saliva corresponding to the preparation method of Example 1 was tested, and a stable color development time of 5-15 minutes can be achieved; further, the test paper can achieve a stable color development time of up to 5-30 minutes through optimized design. For example, by optimizing the concentration of each substance in the reagent and the size of each area in the test paper within the optional range of the concentration of each substance and the optional range of the size of each area provided in the embodiments of the present application, the test paper of the present application can achieve a stable color development time of 5-30 minutes.

[0129] In a pair of ratios, 6 test strips were prepared by replacing the urease concentration in the preparation method of Example 1 with 65 kU / L, and 6 portions of saliva with urea concentrations of 2 mM, 4 mM, 6 mM, 8 mM, 10 mM, and 12 mM were taken as samples, each portion of saliva had an amount of 100 μL, and 6 portions of 100 μL of saliva were dropped on the sampling areas of 6 test strips, respectively, and reacted at room temperature. The color development areas of the saliva of the 6 test strips were photographed at 5 minutes. After analyzing the image, the standard curve was fitted according to the different urea concentrations and the image G / (R+G+B) obtained by analysis. The fitted image is shown in FIG. Figure 4 As shown, Figure 4 The standard curve corresponding to the test paper prepared by the reaction reagent with a urease concentration of 65 kU / L in the present application is shown as follows: Figure 4 As shown, when the urease concentration exceeds the limited range of urease concentration in the aforementioned examples, the linearity of the standard curve is poor.

[0130] In another comparative example, the buffer concentration of the reaction reagent in the preparation method of Example 1 was replaced with 1.25 and the pH of the reaction reagent was 7.4 to prepare 6 test strips, and 6 portions of saliva with urea concentrations of 2mM, 4mM, 6mM, 8mM, 10mM, and 12mM were taken as samples, and the amount of each portion of saliva was 100μL. 6 portions of 100μL of saliva were dropped on the sampling areas of 6 test strips, respectively, and reacted at room temperature. The color development areas of the saliva of the 6 test strips were photographed at 5min. After analyzing the image, the standard curve was fitted according to the G / (R+G+B) of the image obtained by different urea concentrations and analysis. The fitted image is as shown in FIG. Figure 5 As shown, Figure 5 The standard curve corresponding to the test paper prepared by the reaction reagent with a buffer concentration of 1.25 mM and a pH of 7.4 in the present application is shown as follows: Figure 5 As shown, when the buffer concentration and pH value exceed the defined ranges of the buffer concentration and pH value in the previous examples, the standard curve becomes nonlinear.

[0131] It should be noted that Figure 3 The urea concentrations of the samples in the table should not be construed as limiting the urea concentration range that can be detected by the present application. For example, by selecting the urease and the color developing substance within the final concentration range provided in the previous examples of the present application, the test paper can have good detection accuracy within the detection range of different urea concentrations. For example, see Figure 7 , showing a standard curve diagram of a test paper with a urea concentration detection range of 5-30 mM in another embodiment of the present application. As shown in the figure, the standard deviation of the fitted standard curve is 0.9923, which also has good linearity.

[0132] In one embodiment, see Figure 6 Combined with Figure 1 and Figure 2 , Figure 6 The top view of the kit for detecting urea in body fluids in one embodiment of the present application is shown. As shown in the figure, the kit for detecting urea in body fluids includes a shell 8, a base layer 1, a sampling area 2, a reaction area 3, a diffusion area 4, and a color development area 5. The shell 8 is provided with a first window 81 located at the far end of the shell 8, and a second window 82 far away from the first window 81; the sampling area 2, the reaction area 3, the diffusion area 4, and the color development area 5 are arranged on the base layer 1, and the base layer 1 is arranged in the built-in space of the shell 8. The sampling area 2 absorbs the body fluid to be detected through the first window 81, and the diffusion area 4 is arranged on the base layer 1 and connected to the proximal end of the reaction area 3 for lateral transfer of the reactant in the reaction area; the color development area 5 corresponds to the second window 82 and is isolated from the reaction area 3 through the diffusion area 4. The color development area 5 is used to absorb the reactant laterally transferred from the diffusion area 4 to perform a color development reaction using the color development substance in the color development area 5, so as to display the detection result of urea in body fluids through the second window 82.

[0133] In one embodiment, the shell is a detachable structure, so that the test paper / base layer can be fixed in the shell after the shell is disassembled. For example, the shell includes a detachable upper shell and a lower shell. Taking the test paper / base layer arranged in the lower shell as an example, in one example, the lower shell has a fixing groove, and the test paper / base layer can be fixed in the fixing groove; in another example, the test paper / base layer can be fixed to the lower shell by an adhesive structure. It should be noted that the present application does not limit the setting method of the test paper / base layer.

[0134] like Figure 6 As shown, the shape of the first window is an ellipse, and the shape of the second window is a rectangle. It should be noted that the present application does not limit the shapes of the first window and the second window. In other embodiments, the shapes of the first window and the second window may also be other regular shapes or irregular shapes such as rectangles and circles.

[0135] In some embodiments, the size of the area corresponding to the first window needs to be slightly smaller than or equal to the size of the sampling area to ensure that the body fluid is fully in contact with the sampling area and to control the amount of body fluid entering. In one embodiment, the size of the second window needs to be slightly smaller than or equal to the size of the color development area to ensure that the color change in the color development area can be clearly seen through the second window.

[0136] In one embodiment, the first window and the second window are opened in the upper shell of the shell, the first window is located at the far end of the upper shell, and the second window is far away from the first window.

[0137] The base layer is located in the shell. The sampling area is arranged at the distal end of the base layer and is used to absorb the body fluid to be detected through the first window. The reaction area is arranged on the base layer and is used to absorb the body fluid in the sampling area so as to react with the urease in the reaction area. The diffusion area is arranged on the base layer and connected to the proximal end of the reaction area for lateral transfer of the reactant in the reaction area. The color development area is arranged on the base layer corresponding to the second window and is isolated from the reaction area by the diffusion area. The color development area is used to absorb the reactant laterally transferred from the diffusion area so as to perform a color development reaction with the color development substance in the color development area so as to display the detection result of urea in the body fluid through the second window.

[0138] Furthermore, in one embodiment, the kit for detecting urea in body fluids further includes a protective layer covering the reaction area and the color development area.

[0139] Furthermore, in one embodiment, the kit for detecting urea in body fluids further comprises a cover plate disposed at the proximal end of the color development area.

[0140] Here, the configuration and function of each layer (base layer, sampling area, reaction area, diffusion area, color development area, and protective layer) and the cover plate in the kit for detecting urea in body fluids of the present application are the same or similar to the configuration and function of the corresponding layers (base layer, sampling area, reaction area, diffusion area, color development area, and protective layer) and the cover plate in the above-mentioned test paper for detecting urea in body fluids, and will not be repeated here.

[0141] In summary, the test paper and kit for detecting urea in body fluids provided by the present application, through the diffusion zone, the horizontally arranged reaction zone and the color development zone are effectively separated by the diffusion zone in the middle, and the diffusion zone can prevent urease in the reaction zone from entering the color development zone, and then the diffusion zone can terminate the catalytic reaction of urease to improve the stability of the color development reaction in the color development zone, thereby extending the reading time window of the color development result in the color development zone for the convenience of individual users; in addition, the test paper of the present application uses saliva as the liquid to be detected, which can be further convenient for personal use. Moreover, the present application can further extend the reading time window and the stability of the color development and improve the detection accuracy by setting a protective layer. Furthermore, the present application sets the cover plate of the back side of the color development zone as a non-water-absorbing material to further improve the stability of the color development and extend the reading time window.

[0142] In some embodiments of the present application, a method for detecting urea in body fluids is provided, which can be executed by a computer device configured with a system for detecting urea in body fluids. For example, the system for detecting urea in body fluids can be configured as a module in a computer device for execution. The system for detecting urea in body fluids is a software tool or software module that can process data, and it processes data with the help of a hardware device in the computer device and an operating environment provided by an operating system.

[0143] In one embodiment, the computer device can be configured as an electronic device, that is, the method for detecting urea in body fluids is executed by the electronic device. For example, the electronic device includes a computer device such as a desktop computer, a laptop computer, a tablet computer, a smart TV, a smart phone, and a tablet computer. The electronic device can also be an electronic device composed of a host with multiple virtual machines and a human-computer interaction device corresponding to each virtual machine (such as a touch display, a keyboard, and a mouse).

[0144] In one embodiment, the computer device may be configured as a server, that is, the method for detecting urea in body fluids is executed by the server. The server may be arranged on one or more physical servers according to various factors such as function and load. In some examples, the server may be a server based on a cloud architecture, and the server refers to a cloud computing platform provided by a cloud computing provider, and the cloud computing platform can provide services such as IaaS (Infrastructureas-a-Service), PaaS (Platform-as-a-Service), and SaaS (Software-as-a-Service). Among them, the cloud computing platform includes a public cloud (Public Cloud), a private cloud (Private Cloud), and a hybrid cloud (Hybrid Cloud). In some examples, the server may be composed of a distributed or centralized server cluster. For example, the server cluster is composed of at least one physical server. Multiple virtual servers are configured in each physical server, each virtual server runs at least one functional module in the system, and each virtual server communicates through a network.

[0145] In one embodiment, see Figure 8 , which is a flow chart of a method for detecting urea in body fluid in one embodiment of the present application. As shown in the figure, the method for detecting urea in body fluid includes step S110, step S120, and step S130. The following takes the method for detecting urea in body fluid executed by a computer device as an example to describe various embodiments.

[0146] In step S110, the computer device acquires a detection image obtained by photographing the test paper or the reagent kit using an image capture device.

[0147] The detection image is taken within the reading time window after the test paper or the test kit absorbs the body fluid to be detected. Specifically, after the sampling area of ​​the test paper or the test kit described in any of the aforementioned embodiments absorbs the body fluid to be detected, it will react in the reaction area and laterally chromatograph the reactant to the color development area through the diffusion area. After the reactant reacts with the color-developing substance in the color development area, the color development is stable within the reading time window (i.e., the stable display time described above). The user can use the image capture device configured on the computer device (such as the camera configured on the smart phone) or the image capture device independent of the computer device to shoot the test paper or the test kit to obtain the detection image within the reading time window. In the following embodiments, it is explained by taking the example of a user using the image capture device configured on the computer device to shoot to obtain the detection image.

[0148] The detection image includes an image of the color development area in the test paper or the reagent box. Specifically, the detection image includes a color image of the color development area. The image acquisition device is an image camera device that can acquire a color image. For example, the image acquisition device is a camera including a CCD or a CMOS.

[0149] After the computer device acquires the detection image, the computer device executes step S120.

[0150] In step S120, the computer device determines color development data corresponding to the image of the color development area based on the detection image.

[0151] Specifically, the computer device determines the image of the color development area by performing image recognition on the detection image, and then obtains the color development data based on the R, G, and B values ​​of each pixel in the image of the color development area.

[0152] Wherein, the color development data is used to indicate the color of the image in the color development area. In one example, the color development data is the value of G / (R+G+B) of the image in the color development area, and the value of G / (R+G+B) of the image in the color development area is a mean. For example, the mean of the R, G, and B values ​​of all pixels in the image of the color development area can be calculated first, and then the value of G / (R+G+B) of the image can be calculated according to the formula G / (R+G+B). For another example, the G / (R+G+B) value of each pixel can be calculated first, and then the value of G / (R+G+B) of the image in the color development area can be obtained after averaging. It should be noted that, according to different software designs or different color-developing substances in test strips or test kits, in other examples, the color development data can also be the value of R / (R+G+B) or the value of B / (R+G+B) of the image in the color development area.

[0153] In step S130, the computer device determines the urea concentration of the body fluid according to the color development data and a standard curve corresponding to the test paper or the test kit.

[0154] In one embodiment, the standard curve represents the corresponding relationship between the urea concentration of the body fluid and the color development data, and then the urea concentration of the corresponding body fluid can be determined after the standard curve of the test paper or the kit and the color development data are known. Figure 3 The standard curve shown and the calculated value of G / (R+G+B) of the image of the color development area can obtain the corresponding urea concentration. In one example, the standard curve is pre-stored, for example, pre-stored in the computer device or pre-stored in a server connected to the computer device.

[0155] In some embodiments, the standard curves of different batches are different. For this reason, the method for detecting urea in body fluids also includes the step of obtaining the batch information of the test paper or the test kit to determine the standard curve corresponding to the batch information. In one example, the user inputs the batch information of the test paper or the test kit through an input device (such as a touch screen or a keyboard, etc.) of a computer device. In another example, the test paper or the test kit is provided with a mark of batch information, for example, the mark is configured on the base of the test paper or on the housing of the test kit by pasting or printing, and accordingly, the detection image also includes an image of the mark, and then the computer device can obtain the batch information of the test paper or the test kit by identifying the image of the mark.

[0156] In one embodiment, the method for detecting urea in body fluids further includes a step of determining the user's evaluation information based on the determined urea concentration of the body fluid and the type of the body fluid. The evaluation information includes the user's health information and advice information. Examples of the health information include the user's health condition, and / or treatment effect, etc. Examples of the advice information include dietary advice, work and rest advice, and / or treatment advice, etc. In one example, the evaluation information corresponding to different body fluid types and different urea concentrations is pre-stored, and then the computer device can determine the corresponding evaluation information based on the urea concentration of the body fluid and the type of the body fluid. It should be noted that the evaluation information can also be remotely input by a doctor based on different body fluid types and different urea concentrations, and then the computer device can directly obtain the evaluation information to display to the user.

[0157] In one embodiment, see Fig. 9 , which is a structural block diagram of a system for detecting urea in body fluids in one embodiment of the present application. The system 9 for detecting urea in body fluids includes an acquisition module 90, a color development data determination module 91, and a concentration determination module 92.

[0158] The above modules can be implemented in software run by different types of processors. For example, a module of executable code may include one or more physical or logical blocks of computer instructions organized as objects, programs, or functions. However, the executable files of the modules do not have to be physically located together, but may include different commands stored in different locations, which, when logically connected together, comprise the module and achieve the specified goals of the module.

[0159] Of course, the module of executable code can be one or many instructions, and can even be distributed in several different code segments, distributed in different programs and distributed in multiple storage devices. Similarly, operation data can be identified and shown in the module, and the operation data can be embodied in any suitable form and organized in any suitable type of data structure. The operation data can be collected as a single data set, or can be distributed in different locations (including different storage devices), and can exist at least partially as electrical signals in a system or network. When a module or a portion of a module is implemented in software, the software portion is stored on one or more computer-readable media.

[0160] The acquisition module 90 is used to acquire a detection image obtained by photographing the test paper described in any of the above embodiments or the reagent kit described in any of the above embodiments using an image acquisition device; wherein the detection image is photographed within a reading time window after the test paper or the reagent kit absorbs the body fluid to be detected, and the detection image includes an image of the color development area.

[0161] The color development data determination module 91 is used to determine the color development data corresponding to the image of the color development area based on the detection image.

[0162] The concentration determination module 92 is used to determine the color development data corresponding to the image of the color development area based on the detection image.

[0163] In one embodiment, the system for detecting urea in body fluids further includes a standard curve determination module (not shown), which is used to obtain batch information of the test paper or the test kit to determine a standard curve corresponding to the batch information.

[0164] In one embodiment, the system for detecting urea in body fluids further comprises an evaluation information module (not shown), wherein the evaluation information module is used to determine user evaluation information according to the determined urea concentration of the body fluid and the type of the body fluid.

[0165] Here, the working method of each module in the system 9 for detecting urea in body fluids of the present application is the same as or similar to the corresponding steps in the above-mentioned method for detecting urea in body fluids, and will not be repeated here.

[0166] The present application also provides a computer-readable and writable storage medium, on which at least one program is stored. When the at least one program is called, it executes the method for detecting urea in body fluid described in any of the above embodiments.

[0167] In one embodiment, the present application further provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement the method for detecting urea in body fluids described in any of the above-mentioned embodiments.

[0168] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application.

[0169] In the embodiments provided in the present application, the computer readable and writable storage medium may include a read-only memory (ROM), a random access memory (RAM), an EEPROM, a CD-ROM or other optical disk storage device, a magnetic disk storage device or other magnetic storage device, a flash memory, a USB flash drive, a mobile hard disk, or any other medium that can be used to store the desired program code in the form of an instruction or data structure and can be accessed by a computer. In addition, any connection can be appropriately referred to as a computer-readable medium. For example, if the instruction is sent from a website, a server or other remote source using a coaxial cable, an optical fiber cable, a twisted pair, a digital subscriber line (DSL), or wireless technologies such as infrared, radio and microwaves, the coaxial cable, optical fiber cable, twisted pair, DSL, or wireless technologies such as infrared, radio and microwaves are included in the definition of the medium. However, it should be understood that computer readable and writable storage media and data storage media do not include connections, carriers, signals or other temporary media, but are intended to be non-temporary, tangible storage media. Disk and disc, as used in this application, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

[0170] The present application also discloses a computer device, which is used to implement the method for detecting urea in body fluid described in any of the above embodiments. The computer device is a device capable of performing digital calculation, logic processing, and information processing on data. The computer device includes a storage device and a processing device connected to the storage device.

[0171] In some embodiments, the storage device is used to store at least one program, and the at least one program is executable by the processing device to coordinate the method for detecting urea in body fluid described in any of the above embodiments of the storage device.

[0172] Here, the storage device includes, but is not limited to, a read-only memory, a random access memory, and a non-volatile memory. For example, the storage device includes a flash memory device or other non-volatile solid-state storage device. In some embodiments, the storage device may also include a memory remote from one or more processing devices, such as a network attached memory accessed via an RF circuit or an external port and a communication network, wherein the communication network may be the Internet, one or more intranets, a local area network, a wide area network, a storage area network, etc., or a suitable combination thereof. The memory controller may control access to the memory by other components of the device, such as the CPU and peripheral interfaces.

[0173] In some embodiments, the processing device includes one or more processors. The processing device can be operated to perform data read and write operations with the storage device. The processing device includes one or more general-purpose microprocessors, one or more application-specific processors (ASICs), one or more digital signal processors, one or more field programmable logic arrays (FPGAs), or any combination thereof.

[0174] Furthermore, the computer device also includes an interface device. In some embodiments, the interface device includes at least one interface unit, each of which is used to output a visual interface, receive a human-computer interaction event generated according to a user's operation (for example, receiving batch information input by a user), etc. For example, the interface device includes but is not limited to: a serial interface such as an HDMI interface or a USB interface, or a parallel interface, etc. In one embodiment, the interface device also includes a network communication unit, which is a device for data transmission using a wired or wireless network, examples of which include but are not limited to: an integrated circuit including a network card, a local area network module such as a WiFi module or a Bluetooth module, a wide area network module such as a mobile network, etc.

[0175] In one embodiment, the computer device further comprises an input device, which is exemplified by a touch screen connected to the processing device. The input device is used to provide a human-computer interaction interface for user input. In one embodiment, the computer device further comprises an image capture device, which is connected to the processing device and is used to capture the test paper or the reagent box to obtain a detection image.

[0176] In one or more exemplary aspects, the functions described in the method for detecting urea in body fluids described in the present application can be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored or transmitted as one or more instructions or codes to a computer-readable medium. The steps of the method or algorithm disclosed in the present application can be embodied in a processor-executable software module, wherein the processor-executable software module can be located on a tangible, non-temporary computer storage medium. A tangible, non-temporary computer storage medium can be any available medium that a computer can access.

[0177] The flowchart and block diagram in the accompanying drawings described in the present application illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. Based on this, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be realized by a dedicated hardware-based system that performs a specified function or operation, or can be realized by a combination of dedicated hardware and computer instructions.

[0178] In summary, the method and system, computer device, computer-readable storage medium, and computer program product provided in the present application for detecting urea in body fluids acquire a detection image within a longer reading time window of a test strip or a test kit, determine the color data corresponding to the image of the color development area based on the detection image, and use a pre-configured standard curve to accurately determine the urea concentration of the body fluid.

[0179] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A test paper for detecting urea in body fluids, characterized in that: include: A base layer, comprising a proximal end and a distal end extending laterally from the proximal end; A sampling area, disposed at the distal end of the base layer, for absorbing body fluid to be detected; A reaction zone, disposed in the base layer and used to absorb the body fluid in the sampling zone so as to react with the urease in the reaction zone; A diffusion zone, disposed on the base layer and connected to the reaction zone, for lateral chromatography of reactants produced in the reaction zone from the distal end toward the proximal end; The color development zone is arranged on the base layer and isolated from the reaction zone by the diffusion zone, and is used to absorb the reactants from the lateral chromatography of the diffusion zone to perform a color development reaction using the color development substance in the color development zone, so as to display the detection result of urea in the body fluid.

2. The test paper according to claim 1, characterized in that The base layer is a PVC board.

3. The test paper according to claim 1, characterized in that The material of the sampling area includes glass fiber membrane, polyester fiber membrane, absorbent paper, or filter paper.

4. The test paper according to claim 1, characterized in that The substrates of the reaction zone and the diffusion zone include nitrocellulose membrane, PES membrane, PVDF membrane, cellulose acetate membrane, mixed cellulose membrane, absorbent paper, or filter paper.

5. The test paper according to claim 1, characterized in that The reaction zone is formed by disposing prefabricated reaction reagents on a substrate.

6. The test paper according to claim 5, characterized in that The reaction reagents include a buffer, a protective agent, a metal ion chelating agent, a preservative, a surfactant, and urease; wherein the final concentration of urease in the reaction reagents is 10-50 KU / L.

7. The test paper according to claim 6, characterized in that The reaction reagent is prepared by adding potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, sucrose and / or trehalose, bovine serum albumin, ethylenediaminetetraacetic acid, dithiothreitol, and a preservative to water and fully dissolving them, adding a surfactant, adjusting the pH to be acidic, and then adding urease; wherein the final concentrations of potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, sucrose / trehalose, bovine serum albumin, ethylenediaminetetraacetic acid, dithiothreitol, preservative, surfactant, and urease in the reaction reagent are 0.05-0.5 mM, respectively. 0.05-0.5 mM, 2.5-50 mM, 1-5 μM, 1-5 μM, 0.5-5 mM, 5-10 mM, 0.5-2 μM, and 10-50 KU / L.

8. The test paper according to claim 5 or 7, characterized in that The pH value of the reaction reagent is maintained between 4.5 and 6.

5.

9. The test paper according to claim 1, characterized in that The diffusion zone is formed by disposing a dispersion agent on a substrate.

10. The test paper according to claim 9, characterized in that The dispersing agent includes a dispersant; wherein the final concentration of the dispersant is 0.5%-1.5%.

11. The test paper according to claim 10, characterized in that The dispersing agent also includes enzyme inhibitors and / or sodium chloride.

12. The test paper according to claim 10, characterized in that The dispersing agent is prepared by adding sorbitol to water to a final concentration of 0.5%-1.5%.

13. The test paper according to claim 1, characterized in that The substrate of the color development area includes NC membrane, PES membrane, PVDF membrane, cellulose acetate membrane, mixed cellulose membrane, absorbent paper, or filter paper.

14. The test paper according to claim 1, characterized in that The color development area is formed by disposing a pre-made color development reagent on a substrate.

15. The test paper according to claim 14, characterized in that The color developing reagent comprises a buffer, a color developing substance, a preservative, and a surfactant.

16. The test paper according to claim 15, characterized in that The color developing reagent is prepared by adding citric acid monohydrate, sodium citrate dihydrate, phenol red, and a preservative to water and fully dissolving them, then adding a surfactant and adjusting the pH to be acidic; wherein the final concentrations of citric acid monohydrate, sodium citrate dihydrate, phenol red, the preservative, and the surfactant in the color developing reagent are 0.05-0.5mM, 0.05-0.5mM, 1-5mM, 5-10mM, and 0.5-2μM, respectively.

17. The test paper according to claim 14 or 16, characterized in that: The pH value of the color developing reagent is maintained between 2.5 and 5.

5.

18. The test paper according to claim 1, characterized in that The test paper further comprises a protective layer covering any one or more of the reaction area, the diffusion area, and the color development area.

19. The test paper according to claim 18, characterized in that The protective layer is formed by disposing the protective reagent on any one or more of the reaction area, the diffusion area, and the color development area.

20. The test paper according to claim 19, characterized in that The protective reagent includes a buffer and a film-forming agent.

21. The test paper according to claim 20, characterized in that The protective reagent is prepared by adding potassium dihydrogen phosphate and disodium hydrogen phosphate dihydrate into water, fully dissolving them, adjusting the pH to be acidic, and then adding a film-forming agent; wherein the final concentrations of potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate, and the film-forming agent in the protective reagent are 0.05-0.5mM, 0.05-0.5mM, and 0.5%-1.5%, respectively.

22. The test paper according to claim 20, characterized in that The film-forming agent includes chitosan, chitosan quaternary ammonium salt, carboxymethyl chitosan, starch, modified starch, chondroitin sulfate, keratin, silk protein, cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, konjac glucomannan, dextran, alginate, carrageenan, xanthan gum, gum arabic, poloxamer, polyethylene glycol, polylactic acid, polylysine, polylactide, polyvinyl alcohol, polyacrylonitrile, or polyvinyl pyrrolidone.

23. The test paper according to claim 19 or 21, characterized in that: The pH value of the protective reagent is maintained between 4.5 and 6.

5.

24. The test paper according to claim 1, characterized in that The length of the sampling area is between 15mm and 30mm.

25. The test paper according to claim 1, characterized in that The lengths of the reaction zone, diffusion zone, and color development zone are between 5 mm and 15 mm.

26. The test paper according to claim 24 or 25, characterized in that The widths of the sampling area, reaction area, diffusion area, and color development area are between 3-5 mm.

27. The test paper according to claim 1, characterized in that The diffusion zone, the reaction zone, and the color development zone are formed on different substrates, and the diffusion zone is located between the reaction zone and the color development zone to spatially isolate the reaction zone and the color development zone.

28. The test paper according to claim 27, characterized in that The sampling area, the reaction area, the diffusion area, and the color development area are adhered to the base layer through the adhesive on the base layer.

29. The test paper according to claim 27, characterized in that The sampling area, the reaction area, the diffusion area, and the color development area are sequentially overlapped and arranged on the base layer to form a liquid passage through a plurality of overlapping areas.

30. The test paper according to claim 29, characterized in that The length of the overlapping area is 1-2 mm.

31. The test paper according to claim 1, characterized in that The reaction area, diffusion area, and color development area are sequentially formed on different areas of the same substrate.

32. The test paper according to claim 27 or 31, characterized in that The test paper further comprises a cover plate arranged at the proximal end of the color development area; wherein the cover plate is made of a non-water-absorbent material.

33. A kit for detecting urea in body fluids, characterized in that: include: A housing having a built-in space, a first window located at a distal end of the housing, and a second window away from the first window; A base layer, arranged in the built-in space; a sampling area, disposed at the distal end of the base layer and used to absorb body fluid to be detected through the first window; A reaction zone, disposed on the base layer, for absorbing the body fluid in the sampling zone to react with the urease in the reaction zone; a diffusion zone, disposed on the base layer and connected to the proximal end of the reaction zone for laterally transferring reactants in the reaction zone; The color development area is arranged on the base layer corresponding to the second window and is isolated from the reaction area by the diffusion area. It is used to absorb the reactants transferred laterally from the diffusion area to use the color development substances in the color development area to perform a color development reaction, so as to display the detection result of urea in the body fluid through the second window.

34. A method for detecting urea in body fluids, characterized in that: include: Acquire a test image obtained by photographing the test paper according to any one of claims 1 to 32 or the reagent kit according to claim 33 using an image capture device; wherein the test image is photographed within a reading time window after the test paper or the reagent kit absorbs the user's body fluid to be tested, and the test image includes an image of a color development area; Determining color development data corresponding to the image of the color development area based on the detection image; The urea concentration of the body fluid is determined based on the color development data and a standard curve corresponding to the test strip or the kit.

35. The method for detecting urea in body fluid according to claim 34, characterized in that: The step of obtaining the batch information of the test strip or the test kit to determine a standard curve corresponding to the batch information is also included.

36. The method for detecting urea in body fluid according to claim 34, characterized in that: The method further includes determining evaluation information of the user based on the determined urea concentration of the body fluid and the type of the body fluid.

37. A system for detecting urea in body fluids, characterized in that: include: An acquisition module, used to acquire a detection image obtained by photographing the test paper according to any one of claims 1 to 32 or the reagent kit according to claim 33 using an image acquisition device; wherein the detection image is photographed within a reading time window after the test paper or the reagent kit absorbs the body fluid to be detected, and the detection image includes an image of a color development area; a color development data determination module, used to determine the color development data corresponding to the image of the color development area based on the detection image; The concentration determination module is used to determine the urea concentration of the body fluid based on the color development data and the standard curve corresponding to the test paper or the kit.

38. A computer device, characterized in that: include: A storage device for storing at least one program; A processing device is connected to the storage device, and is used to call the at least one program from the storage device and implement the method for detecting urea in body fluid as described in any one of claims 34 to 36 when executing.

39. A computer-readable storage medium, characterized in that: At least one program is stored, and when the at least one program is called and executed by a processor of a computer, the method for detecting urea in body fluid as claimed in any one of claims 34 to 36 is implemented.

40. A computer program product, characterized in that When the computer program product is run on a computer, the computer is caused to execute the method for detecting urea in body fluid according to any one of claims 34 to 36.

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