Test paper for detecting blood glucose and preparation method therefor

Abstract

A test paper for detecting blood glucose, the test paper comprising a substrate layer (10), an electrode layer, a reagent layer and a covering layer, which are sequentially arranged. The reagent layer comprises 2-3 parts of FAD-GDH, 3-5 parts of a high polymer, 2-3 parts of an electronic medium, 0.2-1 part of a surfactant and 1-2 parts of a buffer solution, wherein the high polymer comprises a first polymer having a degree of polymerization of 200-400 and a second polymer having a degree of polymerization of 200-300. The method for preparing the test paper for detecting blood glucose comprises sputtering a metal layer on the substrate layer (10), etching the electrode layer on the metal layer, dropwise adding a reaction liquid in a reaction area of the electrode layer, drying the reaction liquid to obtain the reagent layer, and pasting the covering layer on the electrode layer, which avoids the problems of instability and low accuracy caused by "coffee-ring" effect.

Description

Blood glucose test strip and preparation method thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 29, 2023, with application number "202311866845.4" and invention name "A blood glucose test strip and its preparation method", the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to a blood glucose test strip and a preparation method thereof, belonging to the technical field of blood glucose testing. Background Art

[0003] With the development of blood sugar testing technology, patients are becoming more and more aware of self-testing and monitoring of blood sugar. They test their blood sugar regularly to understand their blood sugar control status and provide a reference for adjusting their diet and treatment plans.

[0004] At present, most blood glucose reagents on the market use carbon paste screen-printed electrode materials and metal-coated electrode materials. Compared with carbon paste screen-printed electrode materials, metal-coated electrode materials have the advantages of softer material, easier processing, hydrophilic electrode surface, good resistance consistency, such as surface resistance accuracy can reach <1%, the material is an inert metal material, strong conductivity, and not easily affected by environmental temperature and humidity. However, as the basic material of blood glucose or other rapid diagnosis test strips, coated metal electrode materials have more prominent problems: Since metal electrodes are produced by coating technology, the electrode surface is very uniform and there is no height difference. The enzyme solution is prone to irregular diffusion on the electrode surface. After curing in the drying tunnel, it is easy to form an obvious "coffee ring", that is, during the drying process of the droplet, the evaporation rate at the edge of the droplet is greater than the evaporation rate at the center of the droplet, thereby generating a supplementary water flow from the center to the edge inside the droplet. Driven by the replenishing water flow, the particulate matter suspended in the droplet is carried to the edge of the droplet and deposited. After the droplet is completely dry, the particles will deposit into a ring along the three-phase contact line, causing the central enzyme layer to become thinner. When testing medium and high concentrations of blood sugar, it will cause low current and poor current consistency, affecting the stability and accuracy of the test paper. Summary of the Invention

[0005] In order to solve the above problems, the present application provides a blood glucose test strip and a preparation method thereof, which solves the problem of test strip instability and low accuracy caused by the "coffee ring" effect when the coated metal electrode material is used as the material of the blood glucose test strip.

[0006] According to one aspect of the present application, a blood glucose test strip is provided, comprising a base layer, an electrode layer, a reagent layer, and a cover layer arranged in sequence; the reagent layer comprising: 2-3 parts FAD-GDH, 3-5 parts polymer, 2-3 parts electron mediator, 0.2-1 part surfactant, and 1-2 parts buffer solution;

[0007] The high polymer includes a first polymer with a polymerization degree of 200-400 and a second polymer with a polymerization degree of 200-300.

[0008] By selecting a polymer with this degree of polymerization, it is possible to prevent the polymer from becoming brittle after curing due to excessively high polymerization, thereby avoiding the enzyme layer from cracking and falling off after curing; at the same time, it is possible to prevent the effective ingredients from not being firmly fixed on the electrode due to too low a degree of polymerization.

[0009] Optionally, the weight ratio of the first polymer to the second polymer is 1:2-4;

[0010] Specifically, the first polymer and the second polymer are independently selected from at least one of sodium hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and polyvinyl pyrrolidone.

[0011] Optionally, the first polymer is sodium hydroxymethylcellulose with a degree of polymerization of 300-400; and the second polymer is hydroxypropyl cellulose with a degree of polymerization of 200-300. By selecting two polymers with different degrees of polymerization, the crystallization rate is controlled so that the polymer with the faster crystallization rate crystallizes first, thereby slowing or hindering the flow of liquid toward the edge, thereby reducing the "anti-coffee ring effect."

[0012] Optionally, the electron mediator is at least one of a ruthenium compound, phenazine methosulfate and thionine; preferably, the electron mediator comprises phenazine methosulfate and thionine in a weight ratio of 1:0.2-0.5; and / or

[0013] The surfactant comprises 0.2-0.5 parts of cetyl ammonium bromide and 0.2-0.5 parts of Trition 100; and / or

[0014] The reagent layer also includes 0.5-1 parts of trehalose and 0.3-0.5 parts of potassium chloride.

[0015] Because the electroactive center of dehydrogenase is hidden relatively deep, common electron mediators cannot transfer the electrons of the enzyme reaction. Therefore, phenazine methyl sulfate is used as a hydrogen donor to transfer electrons from the dehydrogenase active center. The molecular structure of thionine is stable and contains multiple electron donors and acceptors, which enables it to efficiently transfer electrons. Through the synergistic effect of PMS and thionine, the electrons of the blood glucose and enzyme reaction can be transferred to the electrode surface, and then quantitative monitoring of blood glucose can be achieved based on the number of transferred electrons.

[0016] Surfactants are added to regulate the diffusion capacity of the reaction solution, forming a uniform enzyme layer. Trehalose acts as an enzyme protectant to maintain enzyme activity and stability. Potassium chloride provides a suitable microenvironment for the enzyme, ensuring maximum enzyme activity. These components work together to ensure the test paper has high detection sensitivity.

[0017] Optionally, the reagent layer includes: 2 parts of FAD-GDH, 1 part of sodium hydroxymethylcellulose, 3 parts of hydroxypropyl cellulose, 1.4 parts of phenazine methosulfate, 0.6 parts of thionine, 0.5 parts of hexadecyl ammonium bromide, 0.2 parts of Trition 100, 1 part of trehalose, 1 part of phosphate buffer system and 90 parts of water.

[0018] Optionally, the electrode layer includes a pair of reaction electrodes, a pair of hematocrit test electrodes and a sample detection electrode.

[0019] Specifically, the width between adjacent electrodes in the electrode layer is 60-100 μm. By controlling the width between adjacent electrodes, the diffusion speed of the reaction solution is reduced.

[0020] According to another aspect of the present application, a method for preparing any of the above-mentioned blood glucose test strips is provided, comprising the following steps: sputtering a metal layer on a base layer, etching the metal layer to form an electrode layer, dripping a reaction solution into a reaction region of the electrode layer, drying the reaction solution to obtain a reagent layer, and attaching a cover layer above the electrode layer;

[0021] Wherein, the drying temperature of the drying process is gradually reduced.

[0022] Optionally, the drying process includes a high temperature stage, a medium temperature stage and a low temperature stage;

[0023] Specifically, the temperature of the high temperature stage is 60-75°C, the temperature of the medium temperature stage is 40-50°C, and the temperature of the low temperature stage is 30-35°C;

[0024] Preferably, the temperature of the high temperature stage is 65°C, the temperature of the medium temperature stage is 50°C, and the temperature of the low temperature stage is 30°C.

[0025] The initial drying stage is a high-temperature stage to accelerate the volatilization of the solvent, promote the rapid crystallization of the crystalline material, inhibit the flow of liquid to the edges, and ensure the final formation of a uniform thickness of the reagent layer. In the later stages, by setting medium and low temperature stages, the baking temperature is gradually reduced, the curing rate is slowed down, and the coffee ring effect is reduced.

[0026] Optionally, the total time of the drying process is 20-30 minutes;

[0027] Preferably, the duration of the high temperature stage is 3-5 minutes, the duration of the medium temperature stage is 10-15 minutes, and the duration of the low temperature stage is 5-10 minutes.

[0028] Optionally, after sputtering a metal layer onto the substrate, the surface of the metal layer is treated with a plasma air source to reduce the contact angle of the metal layer to 40-70°, preferably 45-55°. By reducing the contact angle of the metal layer, the hydrophilicity of the metal layer surface is enhanced, thereby reducing the thickness of the droplets, improving the uniformity of the droplet diffusion, and accelerating the initial crystallization rate of the crystalline material.

[0029] The beneficial effects of this application include but are not limited to:

[0030] 1. According to a blood glucose test strip provided by the present application, the reagent layer comprises FAD-GDH, a polymer, an electron mediator, a surfactant, and a buffer solution. FAD-GDH can quickly and accurately catalyze the oxidation reaction of glucose, thereby improving the sensitivity of the test strip, and can improve the sensitivity, stability, and accuracy of the test strip. The different crystallization rates in the polymer are utilized to slow down or hinder the flow of liquid to the edge, reducing the phenomenon of irregular diffusion of the enzyme solution. The electron mediator helps to promote the transfer of electrons generated in the glucose oxidation reaction. The surfactant can improve the wettability between the reagent layer and blood, which is conducive to the rapid diffusion of blood and sufficient contact of the reagent layer, thereby improving the accuracy of the test. The above-mentioned configuration improves the performance of the blood glucose test strip.

[0031] 2. According to the preparation method of a blood glucose test strip provided in this application, the method is simple and easy to implement, including the steps of sputtering a metal layer, etching an electrode layer, dripping a reaction liquid, drying and pasting a covering layer, and can efficiently prepare a blood glucose test strip.

[0032] 3. According to the preparation method of a blood glucose test strip provided in the present application, the drying process adopts a gradient curing and drying temperature process, which is beneficial to maintaining the stability and activity of the components in the test strip, and slowing down the replenishment water flow from the center to the edge, which will drive the particulate matter suspended in the droplet to move to the edge of the droplet and deposit; the surface of the metal layer is treated by a plasma air source to reduce the contact angle, which is conducive to forming a uniform and stable solidified enzyme layer, improving the surface consistency, making blood easier to be absorbed, and improving the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0034] FIG1 is a schematic diagram of the layered structure of a blood glucose test strip according to an embodiment of the present application;

[0035] FIG2 is a picture of a blood glucose test strip according to Example 1 of the present application under a microscope;

[0036] FIG3 is a graph showing the height distribution of an enzyme membrane of a blood glucose detection reagent according to an embodiment of the present application;

[0037] FIG4 is a picture of a blood glucose test strip involved in Comparative Example 1 of the present application under a microscope;

[0038] FIG5 is a picture of a blood glucose test strip under a microscope involved in Comparative Example 2 of the present application;

[0039] FIG6 is a schematic diagram of a height distribution curve of an enzyme membrane of a blood glucose detection reagent involved in Comparative Example 2 of the present application;

[0040] FIG7 is a graph showing the height distribution of an enzyme membrane of a blood glucose detection reagent according to Comparative Example 3 of the present application;

[0041] FIG8 is a linear relationship diagram between blood glucose concentration and current of the test paper prepared in Example 1 of the present application.

[0042] List of components and reference numerals: 1 first reaction electrode, 2 second reaction electrode, 3 first hematocrit test electrode, 4 second hematocrit test electrode, 5 sampling detection electrode, 6 exhaust hole, 7 integrated hydrophilic septum, 8 grooved double-sided adhesive layer, 9 hydrophilic film layer. DETAILED DESCRIPTION

[0043] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0044] The present application will be further described below in conjunction with specific embodiments. It is pointed out that the following embodiments should not be understood as limiting the scope of protection of the present application. Simple replacements or adjustments made by ordinary technicians in this field based on the contents of the present application are all within the scope of protection of the present application.

[0045] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0046] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0047] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0048] In addition, in the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0050] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0051] In this application, unless otherwise expressly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0052] In an exemplary embodiment of the present application, FIG1 shows the structure of a blood glucose test strip, which includes, from bottom to top, a base layer 10, an electrode layer, a reagent layer, and a covering layer. The covering layer includes a grooved double-sided adhesive layer 8 and a hydrophilic film layer 9, which form an integrated hydrophilic partition 7 and are arranged above the reagent layer. The hydrophilic film layer 9 is provided with an exhaust hole 6 on one side close to the reagent layer; the electrode layer includes a pair of reaction electrodes (i.e., a first reaction electrode 1 and a second reaction electrode 2), a pair of hematocrit test electrodes (i.e., a first hematocrit test electrode 3 and a second hematocrit test electrode 4) and an injection detection electrode 5, and the reagent layer covers the reaction electrode and the injection detection electrode; the siphon reaction area is composed of the reaction electrode, the hematocrit test electrode and the injection detection electrode, and the siphon pool is composed of the hollow portion of the grooved double-sided adhesive, the hydrophilic film layer and the exhaust hole on the hydrophilic film layer;

[0053] In an exemplary embodiment of the present application, a method for preparing a blood glucose test strip comprises the following steps:

[0054] (1) sputtering a metal layer on the substrate layer, treating the surface of the metal layer with a plasma air source to reduce the contact angle of the metal layer surface to 40-70°;

[0055] (2) Etching the metal layer to form an electrode layer, the electrode layer includes a pair of reaction electrodes, a pair of hematocrit test electrodes and a sample detection electrode, and the width between adjacent electrodes in the electrode layer is 60-100 μm.

[0056] (3) After adding a reaction solution dropwise to the reaction zone of the electrode layer, the reaction solution includes 2-3 parts of FAD-GDH, 3-5 parts of a polymer, 2-3 parts of an electron mediator, 0.2-1 parts of a surfactant and 1-2 parts of a buffer solution; wherein the polymer includes a first polymer with a degree of polymerization of 200-400 and a second polymer with a degree of polymerization of 200-300; the weight ratio of the first polymer to the second polymer is 1:2-4; the electron mediator includes phenazine methyl sulfate and thionine in a weight ratio of 1:0.2-0.5; the surfactant includes 0.2-0.5 parts of hexadecyl ammonium bromide and 0.2-0.5 parts of Trition 100; and further includes 0.5-1 parts of trehalose and 0.3-0.5 parts of potassium chloride.

[0057] (4) drying the reaction solution to obtain a reagent layer, wherein the drying process includes a high temperature stage, a medium temperature stage, and a low temperature stage; the high temperature stage is at a temperature of 60-75°C and lasts for 3-5 minutes, the medium temperature stage is at a temperature of 40-50°C and lasts for 10-15 minutes, and the low temperature stage is at a temperature of 30-35°C and lasts for 5-10 minutes;

[0058] (5) A covering layer is attached on top of the electrode layer.

[0059] Example 1

[0060] (1) sputtering a metal layer on the substrate layer, treating the surface of the metal layer with a plasma air source, and reducing the contact angle of the metal layer surface to 55°;

[0061] (2) Etching the metal layer to form an electrode layer, the electrode layer includes a pair of reaction electrodes, a pair of hematocrit test electrodes and a sample detection electrode, and the width between adjacent electrodes in the electrode layer is 80 μm.

[0062] A reaction solution was added dropwise to the reaction area of ​​the electrode layer and then dried to obtain a reagent layer, wherein the reaction solution included 2 parts of FAD-GDH, 1 part of sodium hydroxymethyl cellulose with a degree of polymerization of 300, 3 parts of hydroxypropyl cellulose with a degree of polymerization of 200, 1.4 parts of phenazine methyl sulfate, 0.6 parts of thionine, 0.5 parts of hexadecyl ammonium bromide, 0.2 parts of Trition 100, 1 part of trehalose, 1 part of phosphate buffer system and 90 parts of water.

[0063] (3) drying the reaction solution to obtain a reagent layer, wherein the drying process includes a high temperature stage, a medium temperature stage, and a low temperature stage; the high temperature stage is at 65°C for 4 minutes, the medium temperature stage is at 45°C for 12 minutes, and the low temperature stage is at 32°C for 8 minutes;

[0064] (4) A covering layer is attached on top of the electrode layer.

[0065] The enzyme membrane prepared by this embodiment was observed using a 200x magnifying glass. As shown in Figure 2, it can be seen that after drying, the liquid as a whole is radiated from the center, with uniform color, and the enzyme membrane is uniform as a whole. The distribution of the enzyme membrane height is characterized using a profilometer. As shown in Figure 3, the overall height distribution of the enzyme membrane is relatively uniform, with an average height of about 5 μm.

[0066] Example 2

[0067] The difference between Example 2 and Example 1 is that, in step (3), the temperature of the high temperature stage is 65°C and the duration is 12 minutes, and the temperature of the low temperature stage is 32°C and the duration is 12 minutes; the remaining steps are the same as Example 1.

[0068] Example 3

[0069] The difference from Example 1 is that in step (3), the temperature of the high-temperature stage is 75°C, the temperature of the medium-temperature stage is 40°C, and the temperature of the low-temperature stage is 30°C; the remaining steps are the same as Example 1.

[0070] Example 4

[0071] The difference from Example 1 is that in step (1), a plasma air source is not used to treat the surface of the metal layer.

[0072] The remaining steps are the same as those in Example 1.

[0073] Example 5

[0074] The difference from Example 1 is that in step (2), the polymer in the reaction solution is selected to be 2 parts of sodium hydroxymethyl cellulose with a degree of polymerization of 300 and 4 parts of hydroxypropyl cellulose with a degree of polymerization of 200 instead of 1 part of sodium hydroxymethyl cellulose with a degree of polymerization of 300 and 3 parts of hydroxypropyl cellulose with a degree of polymerization of 200.

[0075] The remaining steps are the same as those in Example 1.

[0076] Example 6

[0077] The difference from Example 1 is that in step (2), the electron mediator in the reaction solution is selected as 3 parts of ruthenium compound,

[0078] The remaining steps are the same as those in Example 1.

[0079] Example 7

[0080] The difference from Example 1 is that in step (2), the electron mediator in the reaction solution is 2 parts of thionine.

[0081] The remaining steps are the same as those in Example 1.

[0082] Comparative Example 1

[0083] The difference from Example 1 is that in step (2), the polymer in the reaction solution is replaced by 1 part of sodium hydroxymethyl cellulose with a degree of polymerization of 200 and 3 parts of hydroxypropyl cellulose with a degree of polymerization of 500 instead of 1 part of sodium hydroxymethyl cellulose with a degree of polymerization of 300 and 3 parts of hydroxypropyl cellulose with a degree of polymerization of 200.

[0084] The remaining steps are the same as those in Example 1.

[0085] The enzyme membrane prepared in this example was observed using a 200x magnifying glass. As shown in FIG4 , it can be seen that the color of the edge and the middle of the enzyme membrane are inconsistent, and the overall color distribution is uneven, indicating that the enzyme membrane is unevenly distributed.

[0086] Comparative Example 2

[0087] The difference from Example 1 is that in step (2), the polymer in the reaction solution is replaced by 4 parts of sodium hydroxymethyl cellulose with a degree of polymerization of 300 instead of 1 part of sodium hydroxymethyl cellulose with a degree of polymerization of 300 and 3 parts of hydroxypropyl cellulose with a degree of polymerization of 200.

[0088] The remaining steps are the same as those in Example 1.

[0089] Adopt 200 times of magnifying glasses to observe the enzyme membrane that this embodiment prepares, as shown in Figure 5, it can be seen that enzyme membrane edge is inconsistent with middle part color, and color is the state of uneven distribution as a whole, and there is a large amount of crystallization at the edge, and the center is a hollow form, and illustrates that enzyme membrane is unevenly distributed.Utilize profilometer to characterize the distribution of enzyme membrane height, as shown in Figure 6, it can be seen that enzyme membrane presents both sides high, and middle low height distribution, both sides height is about 20um, and middle average height is about 3um.

[0090] Comparative Example 3

[0091] The difference from Example 1 is that in step (3), the drying process is carried out at 45°C for 24 minutes.

[0092] The remaining steps are the same as those in Example 1.

[0093] The enzyme membrane prepared in this example was observed using a 200x magnifying glass. As shown in FIG7 , it can be seen that the color of the edge and the middle of the enzyme membrane are inconsistent, the color is unevenly distributed as a whole, and the center is hollow, indicating that the thickness of the enzyme membrane is unevenly distributed.

[0094] Experimental example

[0095] The blood glucose test strips prepared in the above Examples 1-7 and Comparative Examples 1-3 were connected to the blood glucose meter detection circuit. Blood samples with different blood glucose concentrations were prepared in the laboratory and the test strips were tested. The sensitivity of the blood glucose test strips in detecting blood glucose was tested, and the values ​​of R2, intercept / slope, and repeatability coefficient of variation CV% of the fitting equation were obtained to obtain the test data statistics table as shown in Table 1.

[0096] Table 1

[0097] The closer R2 is to 1, the better the fitting effect is; the intercept / slope value represents the influence of the background current on the low-concentration blood glucose fitting result. The larger the value, the greater the influence. When the intercept / slope is 0, it means that the intercept is 0, which means that the fitting curve passes through the origin, indicating that the background current is 0; the average coefficient of variation is the consistency of the test results of 10 test strips. The smaller the coefficient of variation, the smaller the difference between the test strips. As can be seen from the above table, the blood glucose test strips prepared in this application have high sensitivity, small background current, and high consistency in the test results of the test strips. In addition, Figure 8 is a linear relationship diagram of the test strip blood glucose concentration and current prepared in Example 1 of the present application. It can be seen from the figure that the test strip has a good fitting effect, a small background current, and higher sensitivity.

[0098] The foregoing is merely an embodiment of the present application, and the scope of protection of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the technical ideas and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A blood glucose test strip, wherein, The test strip includes a base layer, an electrode layer, a reagent layer, and a covering layer arranged in sequence; the reagent layer includes: 2-3 parts of FAD-GDH, 3-5 parts of polymer, 2-3 parts of electron mediator, 0.2-1 part of surfactant, and 1-2 parts of buffer solution; Among them, the polymer includes a first polymer with a polymerization degree of 200-400 and a second polymer with a polymerization degree of 200-300.

2. The blood glucose test strip according to claim 1, wherein, The weight ratio of the first polymer to the second polymer is 1:2-4; The first polymer and the second polymer are independently selected from at least one of sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and polyvinylpyrrolidone.

3. The blood glucose test strip according to claim 2, wherein, The first polymer is sodium carboxymethyl cellulose with a polymerization degree of 300-400; the second polymer is hydroxypropyl cellulose with a polymerization degree of 200-300.

4. The blood glucose test strip according to claims 1-3, wherein, The electron mediator is at least one of ruthenium compounds, methylene blue sulfate, and thionine; preferably, the electron mediator includes methylene blue sulfate and thionine with a weight ratio of 1:0.2-0.5; and / or The surfactant includes 0.2-0.5 part of cetyltrimethylammonium bromide and 0.2-0.5 part of Triton 100; and / or The reagent layer further includes 0.5-1 part of trehalose and 0.3-0.5 part of potassium chloride.

5. The blood glucose test strip according to claim 4, wherein, The reagent layer includes: 2 parts of FAD-GDH, 1 part of sodium carboxymethyl cellulose, 3 parts of hydroxypropyl cellulose, 1.4 parts of methylene blue sulfate, 0.6 part of thionine, 0.5 part of cetyltrimethylammonium bromide, 0.2 part of Triton 100, 1 part of trehalose, 1 part of phosphate buffer system, and 90 parts of water.

6. The blood glucose test strip according to any one of claims 1-3, wherein, The electrode layer includes a pair of reaction electrodes, a pair of hematocrit test electrodes, and an injection detection electrode, The width between adjacent electrodes in the electrode layer is 60-100 μm.

7. A method for preparing the blood glucose test strip according to any one of claims 1-6, wherein, Including the following steps: Sputtering a metal layer on the base layer, etching the metal layer to form the electrode layer, dropping a reaction solution on the reaction area of the electrode layer, and drying the reaction solution to obtain the reagent layer, and pasting a covering layer above the electrode layer; Among them, the drying temperature in the drying process gradually decreases.

8. The method according to claim 7, wherein The drying process includes a high-temperature stage, a medium-temperature stage, and a low-temperature stage; The temperature in the high-temperature stage is 60-75 °C, the temperature in the medium-temperature stage is 40-50 °C, and the temperature in the low-temperature stage is 30-35 °C; Preferably, the temperature in the high-temperature stage is 65 °C, the temperature in the medium-temperature stage is 45 °C, and the temperature in the low-temperature stage is 32 °C.

9. The method according to claim 8, wherein, The total time of the drying process is 20-30 min; Preferably, the duration of the high-temperature stage is 3-5 min, the duration of the medium-temperature stage is 10-15 min, and the duration of the low-temperature stage is 5-10 min.

10. The method according to claim 7, wherein, After sputtering a metal layer on the base layer, treating the surface of the metal layer with a plasma air source to reduce the contact angle of the surface of the metal layer to 40-70°, preferably 45-55°.

Images