High-sensitivity blood glucose test paper and preparation method thereof

Abstract

The invention discloses high-sensitivity blood glucose test paper and a preparation method thereof.The high-sensitivity blood glucose test paper comprises a substrate and an electrode arranged on the substrate, and the electrode is prepared from, by mass, 10-15 parts of graphene, 1-3 parts of a conductive material, 2-15 parts of waterborne epoxy resin, 0.1-5.0 parts of a dispersing agent and 0.5-4.0 parts of a curing agent; and 43-60 parts of a solvent. According to the technical scheme, the wettability of the surface of the electrode is improved.

Description

Technical Field

[0001] The invention relates to the technical field of blood sugar test strips, and in particular to a high-sensitivity blood sugar test strip and a preparation method thereof. Background Art

[0002] Fluctuations in blood sugar levels reflect different states of the body. As people's quality of life continues to improve and their living habits change, the number of people who need blood sugar management is increasing. Therefore, for people with high blood sugar, regularly monitoring and controlling blood sugar levels is a key way to maintain health and prevent health problems.

[0003] In the related art, using a blood glucose tester to test blood glucose is a convenient and practical way. People do not need to go to the hospital, but only need to buy a blood glucose tester and blood glucose test strips to monitor their blood glucose levels at home. In actual applications, the electrodes of the blood glucose test strips have low wettability to the enzyme solution, resulting in low sensitivity of blood glucose measurement. Summary of the invention

[0004] The main purpose of the present invention is to provide a high-sensitivity blood sugar test paper and a preparation method thereof, aiming at improving the wettability of the electrode surface.

[0005] To achieve the above-mentioned purpose, the high-sensitivity blood glucose test paper proposed in the present invention comprises a substrate and an electrode arranged on the substrate. The preparation materials of the electrode comprise the following components by weight: 10-15 parts of graphene, 1-3 parts of conductive material, 2-15 parts of water-based epoxy resin, 0.1-5.0 parts of dispersant, 0.5-4.0 parts of curing agent, and 43-60 parts of solvent.

[0006] In one embodiment, the waterborne epoxy resin includes a hydrophilic waterborne epoxy resin.

[0007] In one embodiment, the waterborne epoxy resin has a solid content of 50-80 wt %.

[0008] In one embodiment, at 25° C., the viscosity of the waterborne epoxy resin ranges from 3000 to 13000 cps; and / or the epoxy equivalent weight (EEQ) of the waterborne epoxy resin ranges from 190 g / mol to 300 g / mol.

[0009] In one embodiment, the curing agent includes one or more of aliphatic polyamines, aromatic polyamines, modified polyamines, polyamides or cycloaliphatic amines.

[0010] In one embodiment, the graphene includes graphene nanosheets.

[0011] In one embodiment, the particle size of the graphene is 5-10 μm; and / or the pore size of the graphene is 2-7 nm; and / or the graphene nanosheet has 3-6 layers.

[0012] In one embodiment, the conductive material includes carbon black or metal powder; and / or the dispersant includes dispersant WE-D2645R; and / or the solvent includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, polyvinyl alcohol, polyacrylic acid, polyurethane, acetone, and dichloromethane.

[0013] The present invention also provides a method for preparing a high-sensitivity blood sugar test paper, which is used to prepare the above-mentioned high-sensitivity blood sugar test paper. The preparation method comprises the following steps: Graphene, a conductive material, a dispersant and a solvent are mixed and ground to obtain a mixed slurry; Under stirring conditions of 900-1200 r / min, add water-based epoxy resin to the mixed slurry, stir at 1500-2000 r / min for more than 1 hour, and then grind to a particle size of less than 8 μm; Add curing agent, stir evenly, and degas to obtain conductive carbon paste; The conductive carbon slurry is coated on the substrate and cured to obtain the electrode.

[0014] In one embodiment, in the curing step, curing is carried out at room temperature for 10-15 minutes; and / or, in the step of mixing and grinding the graphene, conductive material, dispersant and solvent, the grinding speed is 2500-3000 r / min and the time is 40-70 minutes.

[0015] The technical solution of the present invention cooperates with each other through specific components and dosages such as graphene, conductive materials and water-based epoxy resin, so that the surface of the cured electrode has good wettability, which is conducive to the adsorption and distribution of glucose oxidase solution or glucose dehydrogenase solution on the electrode surface, and the dried enzyme film can firmly adhere to the electrode, thereby greatly improving the sensitivity and reliability of the blood glucose test strip. In addition, the electrode prepared by the material of this application has good conductivity and stability, thereby further improving the sensitivity of the blood glucose test strip and the accuracy of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 1 of the present invention; Figure 2 This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 2 of the present invention; Figure 3 This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 3 of the present invention; Figure 4 is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 4 of the present invention; Figure 5 This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 5 of the present invention; Figure 6 This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 6 of the present invention; Figure 7 This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 7 of the present invention; Figure 8 This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 8 of the present invention; Fig. 9 This is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 9 of the present invention; Fig.10 is a curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Example 10 of the present invention; Fig.11 A curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Comparative Example 1 of the present invention; Fig.12 A curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Comparative Example 2 of the present invention; Fig.13 A curve diagram showing the relationship between the blood glucose concentration and the response current of the blood glucose test strip of Comparative Example 3 of the present invention; Fig.14 The graph is a relationship between the blood glucose concentration and the response current of the blood glucose test strip of comparative example 4 of the present invention.

[0018] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that if the meaning of "and / or" appears in the full text is to include three parallel solutions, taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0021] "Include", "comprising", "containing", "containing", "having" or other variations herein are intended to cover non-closed inclusions, and no distinction is made between these terms. The term "comprising" means that other steps and ingredients that do not affect the final result may be added. The term "comprising" also includes the terms "mainly consisting of..." and "essentially consisting of..." The compositions and methods / processes of the present invention include, consist of, and are essentially composed of the necessary elements and restrictions described herein and any additional or optional ingredients, components, steps or restrictions described herein. All numerical values ​​or expressions used in the specification and claims involving component amounts, process conditions, etc. should be understood to be modified by "about" in all cases. All ranges involving the same component or property include endpoints, which can be independently combined. Since these ranges are continuous, they include every numerical value between the minimum and maximum values. It should also be understood that any numerical range cited in this application is intended to include all sub-ranges within the range. As used herein, "parts by weight", "parts by weight", "parts by mass" or "parts by mass" are used interchangeably, and the parts by weight may be any fixed weight expressed in milligrams, grams or kilograms (such as 1 mg, 1 g, 2 g, 5 g, or 1 kg, etc.). For example, a composition consisting of 1 part by weight of component a and 9 parts by weight of component b may be a composition consisting of 1 gram of component a + 9 grams of component b, or 10 grams of component a + 90 grams of component b, etc.

[0022] The invention provides a high-sensitivity blood sugar test paper.

[0023] In an embodiment of the present invention, the high-sensitivity blood glucose test strip includes a substrate and an electrode arranged on the substrate. The preparation materials of the electrode include the following components by mass: 10-15 parts of graphene, 1-3 parts of conductive material, 2-15 parts of water-based epoxy resin, 0.1-5.0 parts of dispersant, 0.5-4.0 parts of curing agent, and 43-60 parts of solvent.

[0024] Furthermore, in one embodiment, the preparation material of the electrode includes the following components, measured by mass: 12-15 parts of graphene, 1-3 parts of conductive material, 5-12 parts of water-based epoxy resin, 0.1-3.0 parts of dispersant, 1.2-3.0 parts of curing agent, and 50-55 parts of solvent.

[0025] The technical solution of the present invention cooperates with each other through specific components and dosages such as graphene, conductive materials and water-based epoxy resin, so that the surface of the cured electrode has good wettability, which is conducive to the adsorption and distribution of glucose oxidase solution or glucose dehydrogenase solution on the electrode surface, and the dried enzyme film can firmly adhere to the electrode, thereby improving the sensitivity and reliability of the blood glucose test strip. In addition, the electrode prepared by the material of this application has good conductivity and stability, thereby further improving the sensitivity of the blood glucose test strip and the accuracy of detection.

[0026] It is understood that the electrode is made of conductive carbon slurry, and the electrode is prepared by using the conductive carbon slurry to detect the current signal generated during the reaction between the biological enzyme (glucose oxidase or glucose dehydrogenase) and glucose in the electrode reaction area to obtain the corresponding blood sugar concentration value. The conductive carbon slurry is solidified on the surface of the substrate to form the electrode, and the material of the substrate can be PET, PP, PC or PVC.

[0027] Specifically, graphene is a single-layer hexagonal honeycomb lattice structure formed by sp² hybrid bonding of carbon atoms. It has extremely high conductivity and can significantly improve the conductivity of conductive carbon paste, making the electrode have good and stable conductivity, and the transmission of current signals is faster and more reliable, thereby improving the sensitivity of blood glucose test strips.

[0028] The graphene may be made of nanomaterials. In one embodiment, the graphene includes graphene nanosheets. Graphene nanosheets are composed of single-layer or multi-layer graphene sheets and have many unique properties, including excellent electrical conductivity, thermal conductivity and mechanical properties, thereby further improving the electrical conductivity of the electrode and the structural properties of the electrode.

[0029] Furthermore, in one embodiment, the particle size of the graphene is 5-10 μm to improve the conductivity of the electrode, thereby improving the sensitivity of the blood glucose test strip. In one embodiment, the pore size of the graphene is 2-7 nm, and the porous characteristics of the graphene have a good adsorption effect on the enzyme solution, while increasing the contact area with the enzyme solution, making the reaction area of ​​the sample and the enzyme huge, thereby facilitating the contact between the electrode and the sample and the transmission of the current signal. In one embodiment, the graphene nanosheet is 3-6 layers, which helps to form a tighter microstructure and a good conductive network, and improve the conductivity of the electrode.

[0030] Specifically, the conductive material is used to improve the conductivity of the conductive carbon paste, so that the conductivity and stability of the electrode are more reliable. There are many kinds of conductive materials. In one embodiment, the conductive material includes carbon black or metal powder. Further, in one embodiment, the particle size of the carbon black is 10-120nm. The carbon black can be one or more of acetylene carbon black, conductive furnace black and superconducting carbon black, such as conductive carbon black N990, Super P Li, etc. In another embodiment, the metal powder includes one or more of gold, platinum, palladium, silver, and silver / silver chloride.

[0031] Specifically, water-based epoxy resin is a stable dispersion system in which epoxy resin is dispersed in the form of particles or droplets in a dispersion medium with water as the continuous phase. The conductive carbon paste of the present application improves the wettability of the electrode surface after curing by adding water-based epoxy resin and coordinating other components, which is beneficial to the adhesion of the enzyme solution and also improves the adhesion between the electrode and the substrate. In addition, water-based epoxy resin will not affect the performance of other components and has little interference; and it is a green material with good environmental performance and little environmental pressure.

[0032] In one embodiment, the water-based epoxy resin includes a hydrophilic water-based epoxy resin, so that the cured electrode has good hydrophilicity, the conductive carbon paste has high adhesion to the substrate, and the dispersion stability of the conductive carbon paste is also improved.

[0033] In one embodiment, the waterborne epoxy resin has a solid content of 50-80 wt%. The solid content is the percentage of solid epoxy resin in the epoxy resin dispersion. In order to make the conductive carbon paste have good coating performance and curing speed, the waterborne epoxy resin has a solid content of 50-80 wt%. The waterborne epoxy resin can be BANCO® 900.

[0034] In one embodiment, the epoxy equivalent weight (EEQ) of the waterborne epoxy resin is 190 g / mol to 300 g / mol. Epoxy equivalent weight refers to the number of epoxy groups contained in each epoxy equivalent. By setting the epoxy equivalent weight of the waterborne epoxy resin to 190 g / mol to 300 g / mol, the viscosity of the resin can be prevented from being too high or too low, thereby facilitating the coating of the conductive carbon paste.

[0035] In one embodiment, at 25° C., the viscosity of the waterborne epoxy resin is in the range of 3000-13000 cps. Further, in one embodiment, at 25° C., the viscosity of the waterborne epoxy resin is in the range of 3000-8000 cps. The viscosity of the waterborne epoxy resin is in the range of 3000-8000 cps, which facilitates the coating of the conductive carbon paste, forms a uniform electrode, avoids the electrode curing speed being too fast or too slow, and ensures the thickness of the electrode.

[0036] Specifically, the curing agent includes one or more of aliphatic polyamines, aromatic polyamines, modified polyamines, polyamides or cycloaliphatic amines. The curing agent promotes the cross-linking and curing of the water-based epoxy resin to form a network-like three-dimensional polymer with a high cross-linking density, so that the cured electrode has good wettability and adsorption; and it can increase the curing speed of the electrode, which is conducive to the curing and molding of the electrode. There are many types of curing agents. In one embodiment, it can be ethylenediamine, meta-xylylenediamine, polyamide 650, polyamide 651 or isophorone diamine, etc.

[0037] Specifically, the dispersant helps to disperse graphene, conductive materials and water-based epoxy resin in the solvent. In one embodiment, the dispersant includes dispersant WE-D2645R, which can effectively reduce the phenomenon of agglomeration, aggregation and precipitation, improve the dispersion effect of graphene, etc., and thus improve the stability of the dispersion of materials in the conductive carbon slurry. In another embodiment, the dispersant includes dispersant L-64 (Adeka Corporation), which improves the dispersibility of graphene, conductive materials and water-based epoxy resin in the solvent.

[0038] In one embodiment, the solvent includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, polyvinyl alcohol, polyacrylic acid, polyurethane, acetone, and dichloromethane.

[0039] The present invention also provides a method for preparing a high-sensitivity blood sugar test strip, comprising the following steps: S10, mixing and grinding graphene, a conductive material, a dispersant and a solvent to obtain a mixed slurry; S20, adding water-based epoxy resin to the mixed slurry under stirring conditions of 900-1200 r / min, stirring at 1500-2000 r / min for more than 1 hour, and then grinding to a particle size of less than 10 μm; S30, adding a curing agent, stirring evenly, and degassing to obtain a conductive carbon slurry; S40, coating the conductive carbon slurry on the substrate and curing the slurry to obtain an electrode.

[0040] Specifically, in the step of S10, the graphene, the conductive material, the dispersant and the solvent can be put into a sand mill for grinding, and glass balls or zirconium balls with a diameter of 0.3-0.5 mm can be used for grinding. The ratio of the glass balls or zirconium balls to the grinding material (graphene, conductive material, dispersant and solvent) can be 2:10. In one embodiment, in the step of mixing and grinding the graphene, conductive material, dispersant and solvent, the grinding speed is 2500-3000r / min, and the time is 40-70 minutes.

[0041] In step S20, the mixed slurry is transferred to a mixer and stirred at 900-1200 r / min; then the waterborne epoxy resin is added and stirred at 1500-2000 r / min for more than 1 hour. After stirring, the slurry is ground by putting it into a sand mill and grinding it with glass balls or zirconium balls until the particle size is less than 8 μm.

[0042] In step S30, the curing agent is added to the slurry and stirred evenly. A stirrer can be used for stirring, or the slurry can be ground to a particle size of less than 8 μm in step S20 and then added, and then ground for 5-10 minutes to make the curing agent evenly dispersed. The degassing operation can be static degassing, or the curing agent and slurry are placed in a degassing stirrer and stirred, and the degassing operation is performed while stirring.

[0043] In step S40, the conductive carbon paste is coated on the substrate, which may be printed on the substrate surface, and the conductive carbon paste is cured to form electrodes on the substrate surface. In one embodiment, in the curing step, the curing is performed at room temperature for 10-15 minutes, so that the curing can be performed without heating.

[0044] The embodiments of the present invention will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If specific conditions are not specified in the examples, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially. Example 1

[0045] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 13 parts of graphene, 2 parts of carbon black, 10 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.5 parts of polyamide 650, and 52 parts of N,N-dimethylacetamide. Among them, the water-based epoxy resin comprises BANCO® 900.

[0046] The preparation method of the blood sugar test strip comprises the following steps: S10, graphene, conductive material, dispersant and solvent are mixed and ground at a grinding speed of 2800 r / min for 60 minutes to obtain a mixed slurry; S20, under the stirring condition of 1000r / min, adding water-based epoxy resin to the mixed slurry, stirring at 1600r / min for 70 minutes, and then grinding to a particle size of less than 8μm; S30, adding a curing agent, stirring evenly, and degassing to obtain a conductive carbon slurry; S40, coating the conductive carbon slurry on the substrate and curing it at room temperature for 10 minutes to obtain an electrode. Example 2

[0047] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 15 parts of graphene, 2 parts of carbon black, 10 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.5 parts of polyamide 650, and 52 parts of N,N-dimethylacetamide. Among them, the water-based epoxy resin comprises BANCO® 900.

[0048] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 3

[0049] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 12 parts of graphene, 2 parts of carbon black, 12 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.5 parts of polyamide 650, and 52 parts of N,N-dimethylacetamide. The water-based epoxy resin comprises BANCO® 900.

[0050] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 4

[0051] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 15 parts of graphene, 2 parts of carbon black, 15 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 3.0 parts of polyamide 650, and 52 parts of N,N-dimethylacetamide. Among them, the water-based epoxy resin comprises BANCO® 900.

[0052] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 5

[0053] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 10 parts of graphene, 1.5 parts of carbon black, 8 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.0 parts of polyamide 650, and 50 parts of N,N-dimethylacetamide. The water-based epoxy resin comprises BANCO® 900.

[0054] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 6

[0055] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 11 parts of graphene, 2 parts of carbon black, 5 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.5 parts of polyamide 650, and 50 parts of N,N-dimethylacetamide. Among them, the water-based epoxy resin comprises BANCO® 900.

[0056] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 7

[0057] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation materials of the electrode comprise the following components by weight: 14 parts of graphene, 2 parts of carbon black, 10 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 3.0 parts of m-phenylenediamine, and 52 parts of N,N-dimethylacetamide. The water-based epoxy resin comprises BANCO® 900.

[0058] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 8

[0059] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 13 parts of graphene, 2 parts of carbon black, 10 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.5 parts of m-phenylenediamine, and 50 parts of N,N-dimethylacetamide. The water-based epoxy resin comprises BANCO® 900.

[0060] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 9

[0061] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 14 parts of graphene, 2 parts of carbon black, 10 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.5 parts of polyamide 650, and 50 parts of polyacrylic acid. Among them, the water-based epoxy resin comprises BANCO® 900.

[0062] The preparation method of the blood glucose test strip is the same as that in Example 1. Example 10

[0063] A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate. The electrode preparation material comprises the following components by weight: 13 parts of graphene, 2 parts of carbon black, 12 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 2.5 parts of polyamide 650, and 52 parts of polyacrylic acid. The water-based epoxy resin comprises BANCO® 900.

[0064] The preparation method of the blood glucose test strip is the same as that in Example 1.

[0065] Comparative Example 1 A high-sensitivity blood sugar test strip comprises a substrate and an electrode arranged on one side of the substrate. The preparation materials of the electrode comprise the following components by weight: 13 parts of graphene, 2 parts of carbon black, 2 parts of dispersant WE-D2645R, 2.5 parts of polyamide 650, and 52 parts of N,N-dimethylacetamide.

[0066] The preparation method of the blood glucose test strip is the same as that in Example 1.

[0067] Comparative Example 2 A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate. The electrode preparation material comprises the following components by weight: 13 parts of graphene, 2 parts of carbon black, 30 parts of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 10 parts of polyamide 650, and 52 parts of N,N-dimethylacetamide. The water-based epoxy resin comprises BANCO® 900.

[0068] The preparation method of the blood glucose test strip is the same as that in Example 1.

[0069] Comparative Example 3 A high-sensitivity blood glucose test strip comprises a substrate and an electrode disposed on one side of the substrate, wherein the preparation material of the electrode comprises the following components by weight: 13 parts of graphene, 2 parts of carbon black, 1 part of water-based epoxy resin, 2 parts of dispersant WE-D2645R, 0.1 parts of polyamide 650, and 52 parts of N,N-dimethylacetamide. The water-based epoxy resin comprises BANCO® 900.

[0070] The preparation method of the blood glucose test strip is the same as that in Example 1.

[0071] The components and quantities of the above Examples 1 to 10 and Comparative Examples 1 to 3 are shown in Table 1 and are prepared according to the above method for preparing blood glucose test strips.

[0072] Table 1 Components and quantities of each sample

[0073] In addition, the applicant purchased a popular blood glucose test strip (electrochemical type) on the market as Comparative Example 4.

[0074] In order to verify the various properties of the blood glucose test strip electrodes, the samples were sprayed with enzyme solution (containing a glucose dehydrogenase aqueous solution with a mass concentration of 1‰) and dried, and the performance tests were carried out with Comparative Example 4, such as conductivity, wettability, and adhesion. The test results are shown in Table 2, Figures 1 to 14 .

[0075] (1) Wetting performance: On the electrode surface that was not sprayed with enzyme solution, drop the enzyme solution on the electrode surface and measure the contact angle of the enzyme solution on the electrode surface using a contact angle meter (DSA100). The test was repeated 5 times and the average value was taken.

[0076] (2) Adhesion performance: Rub the electrode on the substrate for five minutes and observe whether the enzyme film formed by the enzyme solution detaches.

[0077] (3) Sensitivity: The IT testing technology was used on an electrochemical workstation to test the equilibrium current under different blood glucose concentrations and obtain the response current and blood glucose concentration curve.

[0078] (4) Conductivity: The resistivity of the electrode was tested using a four-probe test method within three months after preparation and one year at room temperature.

[0079] Table 2 Sample performance test results

[0080] According to Table 1 and Table 2, the contact angles of the electrodes of Examples 1 to 10 are all less than 9°, while the contact angles of Comparative Examples 1 to 3 are all greater than the embodiments, and the contact angles of Comparative Examples 1 to 3 are all greater than 30°, which are much greater than the contact angles of the embodiments of the present application; Comparative Example 4 is a commercial product, and no detection is performed because an enzyme film has been formed. Therefore, compared with the existing blood sugar test strips and comparative examples, the contact angle of the blood sugar test strip electrodes of the present application is small, and the wetting performance is good, which is conducive to the adsorption and distribution of glucose oxidase solution or glucose dehydrogenase solution on the electrode surface, so that the blood sugar test strips of the present application have higher sensitivity.

[0081] As for the adhesion performance, after rubbing for five minutes, the enzyme membranes of Examples 1 to 10 were all intact, and no detachment was observed with the naked eye. The conductive carbon paste of Comparative Example 1 did not add water-based epoxy resin, and the detachment area was as high as 80%. Comparative Examples 2 and 3 also detached over a large area. In addition, the detachment area of ​​Comparative Example 4 was about 15%. Therefore, it is shown that the adhesion performance of the blood glucose test paper electrode of the present application is good, and it can be firmly adhered to the enzyme membrane.

[0082] The linear fitting curves of different blood glucose concentrations and response currents of the samples are shown in Figures 1 to 14 The sensitivity of Examples 1 to 10 is 0.8069-0.8682 μA / mmol / L, corresponding to the linear fitting curve R 2 The minimum is 0.987, indicating that the electrode prepared in this application has a good linear response to glucose and the sensitivity of the blood glucose test strip is high. The sensitivity of Comparative Example 1 is only 0.005 μA / mmol / L, while Comparative Examples 2 and 3 have linear fitting curves R 2 Greater than 0.9, but its sensitivity is less than 0.16 μA / mmol / L. The linear fitting curve R of Comparative Example 4 2 It is 0.9868, and its sensitivity is 0.0.3558μA / mmol / L, which is less than half of the blood glucose test strip in this application.

[0083] According to the four-probe test results, the resistivity of Examples 1 to 10 within three months and one year is 0.007-0.009Ω·cm, which is less than 0.031Ω·cm and 0.042Ω·cm of Comparative Example 4, while the resistivity of Comparative Examples 1 to 3 is greater than 0.1Ω·cm within three months of preparation. The resistivity of Comparative Example 1 after one year increases by 86.9% compared with that of three months, but the resistivity of Examples 1 to 10 increases by only 16.7% in one year, or even remains unchanged. Therefore, it is shown that the electrode of the present application has excellent conductivity and high stability.

[0084] In summary, the electrode of the blood glucose test strip of the present application has good wettability and adhesion, which is conducive to the adsorption of the enzyme solution and the adhesion of the enzyme film after drying, so that the blood glucose test strip has high sensitivity and reliability. At the same time, the electrode of the blood glucose test strip of the present application has excellent conductivity and high stability, which further improves the detection sensitivity of the blood glucose test strip.

[0085] The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art. Unless otherwise specified, the meanings of the terms in this specification are the same as those generally understood by those skilled in the art, but in case of conflict, the definitions in this specification shall prevail.

[0086] The foregoing examples are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to claim the widest possible range that can be conceived, and the embodiments presented herein are only illustrations of selected implementations according to the combination of all possible embodiments. Therefore, it is the applicant's intention that the appended claims are not limited by the selection of examples that illustrate the features of the present invention. Some numerical ranges used in the claims also include sub-ranges within them, and changes in these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A high-sensitivity blood sugar test strip, characterized in that: The blood glucose test strip comprises a substrate and an electrode arranged on the substrate. The preparation materials of the electrode comprise the following components by weight: 10-15 parts of graphene, 1-3 parts of conductive material, 2-15 parts of water-based epoxy resin, 0.1-5.0 parts of dispersant, 0.5-4.0 parts of curing agent, and 43-60 parts of solvent.

2. The highly sensitive blood sugar test strip according to claim 1, characterized in that: The waterborne epoxy resin includes a hydrophilic waterborne epoxy resin.

3. The highly sensitive blood sugar test strip according to claim 2, characterized in that: The waterborne epoxy resin has a solid content of 50-80 wt %.

4. The highly sensitive blood sugar test strip according to claim 3, characterized in that: The viscosity of the waterborne epoxy resin is in the range of 3000-13000 cps at 25°C; and / or, The waterborne epoxy resin has an epoxy equivalent weight (EEQ) of 190 g / mol to 300 g / mol.

5. The highly sensitive blood sugar test strip according to claim 4, characterized in that: The curing agent includes one or more of aliphatic polyamines, aromatic polyamines, modified polyamines, polyamides or cycloaliphatic amines.

6. The high-sensitivity blood glucose test strip according to any one of claims 1 to 5, characterized in that: The graphene includes graphene nanosheets.

7. The high-sensitivity blood sugar test strip according to claim 6, characterized in that: The graphene has a particle size of 5-10 μm; and / or, The pore size of the graphene is 2-7 nm; and / or, The graphene nanosheets have 3 to 6 layers.

8. The highly sensitive blood sugar test strip according to claim 7, characterized in that: The conductive material comprises carbon black or metal powder; and / or, The dispersant includes dispersant WE-D2645R; and / or, The solvent includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, polyvinyl alcohol, polyacrylic acid, polyurethane, acetone, and dichloromethane.

9. A method for preparing a high-sensitivity blood glucose test strip according to any one of claims 1 to 8, characterized in that: The following steps are involved: Graphene, a conductive material, a dispersant and a solvent are mixed and ground to obtain a mixed slurry; Under stirring conditions of 900-1200 r / min, add water-based epoxy resin to the mixed slurry, stir at 1500-2000 r / min for more than 1 hour, and then grind to a particle size of less than 8 μm; Add curing agent, stir evenly, and degas to obtain conductive carbon paste; The conductive carbon slurry is coated on the substrate and cured to obtain the electrode.

10. The method for preparing a high-sensitivity blood glucose test strip according to claim 9, wherein: In the curing step, curing is performed at room temperature for 10-15 minutes; and / or, In the step of mixing and grinding the graphene, conductive material, dispersant and solvent, the grinding speed is 2500-3000 r / min and the grinding time is 40-70 minutes.

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