A method for manufacturing a blood glucose test paper and a blood glucose test paper

Abstract

The application discloses a preparation method of blood glucose test paper and the blood glucose test paper, and mainly relates to the technical field of blood glucose detection. The preparation method of the blood glucose test paper comprises the following steps: forming an electrode layer on a substrate; arranging a functional mixed enzyme liquid on the substrate and the electrode layer to form a functional enzyme film, wherein the functional mixed enzyme liquid comprises polyvinylpyrrolidone; arranging a hydrophilic film on the functional enzyme film; and arranging an upper cover on the hydrophilic film to form the blood glucose test paper. Through the above steps, the generation yield of the blood glucose test paper is improved, and the dispersion degree of blood glucose detection results is reduced.

Description

Technical Field

[0001] This application relates to the field of blood glucose detection technology, and in particular to a method for preparing a blood glucose test strip and the blood glucose test strip itself. Background Technology

[0002] Blood glucose test strips are widely used in the field of in vitro diagnostics, especially in the daily monitoring of chronic diseases such as diabetes. As a fast and convenient testing tool, the performance of blood glucose test strips is directly related to the patient's accurate understanding of their own blood glucose level, which in turn affects the adjustment of treatment plans and the control of the disease. The accuracy of the test largely depends on the performance of the enzyme membrane.

[0003] The enzyme membrane in existing blood glucose test strips is prone to breakage during the pressing and cutting process. Summary of the Invention

[0004] The purpose of this application is to provide a method for preparing a blood glucose test strip and a blood glucose test strip, thereby improving the yield of blood glucose test strip production and reducing the dispersion of blood glucose test results.

[0005] This application discloses a method for preparing a blood glucose test strip, the method comprising the following steps:

[0006] S1: An electrode layer is formed on the substrate;

[0007] S2: A functional mixed enzyme solution is disposed on the substrate and the electrode layer to form a functional enzyme membrane, wherein the functional mixed enzyme solution includes polyvinylpyrrolidone.

[0008] S3: A hydrophilic membrane is disposed on the functional enzyme membrane;

[0009] S4: A top cover is provided on the hydrophilic membrane to form the blood glucose test strip.

[0010] Optionally, step S1: forming an electrode layer on the substrate includes:

[0011] S11: The substrate is subjected to hydrophilic treatment to form a hydrophilic surface on one side of the substrate;

[0012] S12: An electrode layer is formed on the hydrophilic surface of the substrate.

[0013] Optionally, step S2: distributing a functional mixed enzyme solution on the substrate and the electrode layer to form a functional enzyme membrane, wherein the functional mixed enzyme solution includes polyvinylpyrrolidone, includes:

[0014] S21: A bottom layer mixture is disposed on the hydrophilic surface of the substrate and the electrode layer, and pre-dried to form a bottom layer film;

[0015] S22: A functional mixed enzyme solution is placed on the bottom layer membrane and completely dried to form a functional enzyme membrane. The functional mixed enzyme solution includes polyvinylpyrrolidone, while the bottom layer mixture does not contain polyvinylpyrrolidone.

[0016] Optionally, in step S21: providing a bottom layer mixture on the hydrophilic surface of the substrate and the electrode layer, and pre-drying to form a bottom layer film:

[0017] The water content of the bottom membrane is 0.5% to 10%.

[0018] This application also discloses a blood glucose test strip, which is prepared by the method described above. The blood glucose test strip includes a substrate, and an electrode layer, a functional enzyme membrane, a hydrophilic membrane, and a top cover sequentially disposed on the substrate. The functional enzyme membrane includes polyvinylpyrrolidone.

[0019] Optionally, the blood glucose test strip further includes a bottom membrane, the bottom membrane not including polyvinylpyrrolidone, the bottom membrane being disposed on the side of the functional enzyme membrane opposite to the hydrophilic membrane, the area of ​​the functional enzyme membrane being smaller than the area of ​​the bottom membrane, and the orthographic projection of the bottom membrane on the substrate covering the orthographic projection of the functional enzyme membrane on the substrate.

[0020] Optionally, the molecular weight of polyvinylpyrrolidone is 10,000 g / mol to 1,300,000 g / mol; the content of polyvinylpyrrolidone is 0.01% to 5% (w / v).

[0021] Compared to existing solutions that do not contain polyvinylpyrrolidone in their functional enzyme mixtures, this application enhances the toughness and cohesion of the enzyme membrane by adding polyvinylpyrrolidone to the functional enzyme mixture. The resulting functional enzyme membrane can absorb the mechanical stress during the pressing and cutting process, inhibit the generation and propagation of microcracks, and prevent the functional enzyme membrane of the blood glucose test strips from breaking and peeling off after cutting. This improves the yield of blood glucose test strips and reduces the dispersion of blood glucose test results. Attached Figure Description

[0022] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:

[0023] Figure 1 This is a schematic diagram of a method for preparing a blood glucose test strip according to an embodiment of this application;

[0024] Figure 2 This is a schematic diagram illustrating the detection data of a blood glucose test strip obtained through a different processing method according to an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the functional film layer obtained after slicing blood glucose test strips through a different processing method according to an embodiment of this application;

[0026] Figure 4 This is a schematic diagram of a method for preparing a bilayer enzyme membrane according to an embodiment of this application;

[0027] Figure 5 This is a schematic diagram of a blood glucose test strip according to an embodiment of this application;

[0028] Figure 6 This is a planar schematic diagram of a functional enzyme membrane according to an embodiment of this application;

[0029] Figure 7 This is a cross-sectional schematic diagram of a functional enzyme membrane according to an embodiment of this application.

[0030] Among them, 100 is the blood glucose test strip; 110 is the substrate; 120 is the electrode layer; 130 is the bottom membrane; 140 is the functional enzyme membrane; 150 is the hydrophilic membrane; and 160 is the top cover. Detailed Implementation

[0031] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0032] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0033] In addition, terms such as “center,” “horizontal,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” that indicate orientation or positional relationship are based on the orientation or relative positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0034] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0036] Figure 1 This is a schematic diagram of a method for preparing a blood glucose test strip according to an embodiment of this application, as shown below. Figure 1 As shown, this application discloses a method for preparing a blood glucose test strip, the method comprising the following steps:

[0037] S1: An electrode layer is formed on the substrate;

[0038] For example, the substrate 110 is PET (polyethylene terephthalate), which is a common polyester film, and is used as the material of the substrate 110 in this application.

[0039] For example, the electrode layer 120 may be a carbon electrode, which will not be elaborated here.

[0040] S2: A functional mixed enzyme solution is disposed on the substrate and the electrode layer to form a functional enzyme membrane, wherein the functional mixed enzyme solution includes polyvinylpyrrolidone.

[0041] S3: A hydrophilic membrane is disposed on the functional enzyme membrane;

[0042] S4: A top cover is provided on the hydrophilic membrane to form the blood glucose test strip.

[0043] For example, the top cover 160 may be made of rigid or semi-rigid plastic film such as PVC or PC.

[0044] The existing functional enzyme mixture mainly includes phosphate buffer, Triton X-100, trehalose, PVA, potassium ferricyanide, and glucose oxidase. After the cap 160 is placed on the hydrophilic membrane 150, it needs to be pressed together to obtain the blood glucose test strip 100. This requires cutting the strips to obtain the blood glucose test strips. Consequently, the existing functional enzyme membrane may crack or partially peel off under mechanical stress.

[0045] Therefore, this application adds polyvinylpyrrolidone (PVP) to the functional mixed enzyme solution. The long polymer chain of PVP can form a flexible interpenetrating network structure inside the functional enzyme membrane 140, thereby improving the toughness and cohesion of the functional enzyme membrane. It can absorb the mechanical stress during the pressing and cutting process, inhibit the generation and propagation of microcracks, and thus significantly improve the mechanical stability and structural integrity of the functional enzyme membrane 140.

[0046] Compared to existing functional enzyme mixtures that do not contain polyvinylpyrrolidone (PVP), this application enhances the toughness and cohesion of the enzyme membrane by adding PPVP to the functional enzyme mixture. This results in a functional enzyme membrane that can absorb mechanical stress during pressing and cutting, inhibiting the generation and propagation of microcracks. This prevents the functional enzyme membrane from fracturing and peeling off after slicing the blood glucose test strips, thereby improving the yield of blood glucose test strips and reducing the dispersion of blood glucose test results.

[0047] While adding polyvinylpyrrolidone to the functional enzyme mixture can inhibit the generation and propagation of microcracks, it reduces the interfacial bonding between the functional enzyme membrane 140 and the substrate 110. This leads to delamination of the functional enzyme membrane 140 and the substrate 110 after long-term storage. Therefore, this application also performs a hydrophilic treatment on the substrate 110, specifically:

[0048] S1: The step of forming an electrode layer on the substrate includes:

[0049] S11: The substrate is hydrophilically treated to form a hydrophilic surface on one side of the substrate;

[0050] For example, the hydrophilic treatment includes plasma treatment, corona treatment, and chemical treatment, and is not limited thereto.

[0051] S12: An electrode layer is formed on the hydrophilic surface of the substrate.

[0052] By hydrophilically treating the substrate 110 and adding a functional mixed enzyme solution containing polyvinylpyrrolidone, the mechanical stability of the functional enzyme membrane 140 can be improved, while the interfacial bonding force between the functional enzyme membrane 140 and the substrate 110 can be effectively enhanced. This solves the problem of delamination or peeling that may occur after long-term storage due to the addition of polyvinylpyrrolidone. Even during long-term storage, the functional enzyme membrane 140 is not easily peeled off from the surface of the substrate 110, ensuring the structural stability and performance reliability of the blood glucose test strip 100 during storage.

[0053] Figure 2 This is a schematic diagram illustrating the detection data of a blood glucose test strip obtained through a different processing method according to an embodiment of this application. Figure 3 This is a schematic diagram of the functional film layer obtained after slicing blood glucose test strips through a different processing method according to an embodiment of this application, as shown below. Figures 2-3 As shown:

[0054] Figure 2 In this context, mean represents the average value, SD represents the standard deviation, and CV represents the coefficient of variation, also known as the relative standard deviation. Figure 2 The experimental group consisted of blood glucose test strips prepared using four different methods.

[0055] Figure 3 A represents the blood glucose test strip prepared using the first method. Figure 3 B represents the blood glucose test strip prepared using the second method. Figure 3 C represents the blood glucose test strip prepared using the third method. Figure 3 D represents the blood glucose test strip prepared using the fourth method.

[0056] For example, the following shows four different methods of preparing blood glucose test strips 100:

[0057] The first method: The corresponding functional mixed enzyme solution does not include polyvinylpyrrolidone, and the substrate 110 is not hydrophilically treated.

[0058] Prepare the first functional mixed enzyme solution: Prepared from the following components by weight: 50 mmol / L phosphate buffer, 0.05% Triton X-100, 1% trehalose, 1% PVA, 5% potassium ferricyanide, and 1% glucose oxidase.

[0059] The first functional mixed enzyme solution is coated onto the electrode layer using an enzyme application machine. After drying, the hydrophilic membrane 150 and the top cover 160 are attached, pressed together, and cut to obtain the blood glucose test strip for testing.

[0060] Then, a test was performed using 0.4V, and the test value was recorded.

[0061] Test results: From Figure 2 and Figure 3 As can be seen from A, after slicing, the functional enzyme membrane 140 showed fragmentation, peeling and discontinuity, and the CV values ​​of the corresponding test samples T1, T2 and T3 were 6.5%, 6.7% and 6.2%, respectively.

[0062] The second method: The corresponding functional mixed enzyme solution includes polyvinylpyrrolidone, but the substrate 110 is not hydrophilically treated.

[0063] Prepare the second type of functional mixed enzyme solution: Prepare the following components by weight: 50 mmol / L phosphate buffer, 0.05% Triton X-100, 1% trehalose, 1% PVA, 1% PVP, 5% potassium ferricyanide, and 1% glucose oxidase; the rest is the same as the first method.

[0064] Test results: From Figure 3 As can be seen from B, the uniformity of the functional enzyme membrane 140 improved after slicing, but fragmentation and discontinuity still existed. The CV values ​​of the corresponding test samples T1, T2, and T3 were 5.6%, 5.6%, and 5.3%, respectively.

[0065] The third method: The corresponding functional mixed enzyme solution does not include polyvinylpyrrolidone, but the substrate 110 is hydrophilically treated.

[0066] The substrate 110 is hydrophilically treated, and the functional mixed enzyme solution is the same as in the second method.

[0067] Test results: From Figure 3 As can be seen from C, the enzyme membrane still exhibits peeling and discontinuity after slicing, with the corresponding CV values ​​for test samples T1, T2, and T3 being 5.7%, 4.8%, and 5.9%, respectively.

[0068] The fourth method: The corresponding functional mixed enzyme solution includes polyvinylpyrrolidone, and the substrate 110 is hydrophilically treated at the same time.

[0069] The substrate 110 is hydrophilically treated, and the functional mixed enzyme solution is the same as in the second method.

[0070] Result: From Figure 3 As can be seen from D, the enzyme membrane was relatively intact after slicing, and no obvious cracks or peeling were observed. The CV values ​​of the corresponding test samples T1, T2, and T3 were 2.0%, 2.0%, and 1.8%, respectively.

[0071] The test value corresponding to sample number T1 represents the actual single-sample blood glucose concentration (in millimoles per liter, mmol / L) obtained when the blood glucose test strip was used to test sample T1, and was measured 8 times. The test value corresponding to sample number T2 represents the actual single-sample blood glucose concentration (in millimoles per liter, mmol / L) obtained when the blood glucose test strip was used to test sample T2, and was measured 8 times. The test value corresponding to sample number T3 represents the actual single-sample blood glucose concentration (in millimoles per liter, mmol / L) obtained when the blood glucose test strip was used to test sample T3, and was measured 8 times.

[0072] By hydrophilically treating the substrate 110 and adding polyvinylpyrrolidone to the functional mixed enzyme solution, the functional enzyme membrane 140 of the slit blood glucose test strip is more intact and the CV value is significantly improved.

[0073] Figure 4 This is a schematic diagram of a method for preparing a bilayer enzyme membrane according to an embodiment of this application, as shown below. Figure 4 As shown, the addition of polyvinylpyrrolidone to the functional enzyme mixture increases its viscosity, leading to decreased coating uniformity. Therefore, this application also includes a bottom layer membrane 130 before coating the functional enzyme mixture. Specifically:

[0074] Step S2: The step of depositing a functional mixed enzyme solution on the substrate and the electrode layer to form a functional enzyme membrane, wherein the functional mixed enzyme solution includes polyvinylpyrrolidone, includes:

[0075] S21: A bottom layer mixture is disposed on the hydrophilic surface of the substrate and the electrode layer, and pre-dried to form a bottom layer film;

[0076] S22: A functional mixed enzyme solution is placed on the bottom layer membrane and completely dried to form a functional enzyme membrane. The functional mixed enzyme solution includes polyvinylpyrrolidone, while the bottom layer mixture does not contain polyvinylpyrrolidone.

[0077] For example, the bottom mixture may not contain glucose oxidase, but it may also contain glucose oxidase to avoid reducing the concentration of the functional enzyme solution. For example, the bottom mixture includes 50 mmol / L phosphate buffer, 0.05% Triton X-100, 1% trehalose, 1% PVA, 5% potassium ferricyanide, and 1% glucose oxidase.

[0078] Specifically, by first coating a bottom layer mixture onto the hydrophilic surface of the substrate 110 and pre-drying it to form a bottom layer film 130, and then directly coating a functional mixed enzyme solution onto the bottom layer film 130 and completely drying it, a functional enzyme film 140 is formed. By first coating a bottom layer mixture without polyvinylpyrrolidone and pre-drying it to form the bottom layer film 130, a smooth and uniform transition interface can be constructed on the surface of the substrate 110 and the electrode layer 120. When a functional mixed enzyme solution with higher viscosity containing polyvinylpyrrolidone is then coated onto the bottom layer film 130, the spreading of the functional mixed enzyme solution is no longer affected by the surface state of the substrate 110, resulting in higher leveling and film uniformity. This avoids the uneven thickness phenomenon caused by the slow spreading of high-viscosity fluids when the high-viscosity functional mixed enzyme solution is directly coated onto the surface of the hydrophilically treated substrate 110, thereby improving the coating uniformity of the functional mixed enzyme solution and avoiding inconsistent response currents.

[0079] Furthermore, in step S21: providing a bottom layer mixture on the hydrophilic surface of the substrate and the electrode layer, and pre-drying to form a bottom layer film: the water content of the bottom layer film 130 is 0.5% to 10%.

[0080] For example, during pre-drying, the drying temperature is controlled at 45℃~75℃ and the drying time is controlled at 15~30min, so that the moisture content of the bottom membrane 130 is 0.5%~10%. This can avoid the bottom membrane 130 being too dry, which would reduce the binding force between the functional mixed enzyme solution and the bottom membrane 130, and can also avoid the bottom membrane 130 being too wet, which would cause the bottom mixed solution to mix with the functional mixed enzyme solution.

[0081] For example, if the thickness of the bottom film 130 is too small, the bonding force with the substrate 110 will be weak, and local delamination is likely to occur during pre-drying. If the thickness of the bottom film 130 is too large, the internal stress will increase after drying, and the bottom film 130 will be brittle and prone to cracking during slitting.

[0082] Therefore, the thickness of the bottom membrane 130 can be controlled between 0.5 μm and 3 μm, and the thickness of the functional enzyme membrane 140 can be controlled between 0.8 μm and 2.5 μm.

[0083] Figure 5 This is a schematic diagram of a blood glucose test strip according to an embodiment of this application, as shown below. Figure 5 As shown, this application also discloses a blood glucose test strip 100, which includes a substrate 110, and an electrode layer 120, a functional enzyme membrane 140, a hydrophilic membrane 150 and a top cover 160 sequentially disposed on the substrate 110. The functional enzyme membrane 140 includes polyvinylpyrrolidone.

[0084] Compared to existing blood glucose test strips where the functional enzyme mixture does not contain polyvinylpyrrolidone, the blood glucose test strip 100 of this application contains polyvinylpyrrolidone in its functional enzyme mixture, thereby improving the toughness and cohesion of the functional enzyme membrane 140. This allows the functional enzyme membrane 140 to absorb the mechanical stress during the pressing and cutting process, making it less prone to the generation and propagation of microcracks. This avoids the phenomenon of the functional enzyme membrane 140 of the blood glucose test strip breaking and local peeling after cutting, thereby improving the yield of blood glucose test strip 100 and reducing the dispersion of blood glucose test results.

[0085] The molecular weight of the polyvinylpyrrolidone is 10,000 g / mol to 1,300,000 g / mol, preferably 30,000 g / mol to 400,000 g / mol, to avoid insufficient toughness and weak anti-fracture effect due to too small a molecular weight; it can also prevent uneven coating due to high viscosity of the functional mixed enzyme solution due to too large a molecular weight; the content of the polyvinylpyrrolidone is 0.01% to 5% (w / v), that is, 0.01 g of polyvinylpyrrolidone per 100 mL of solution to 5 g of polyvinylpyrrolidone per 100 mL of solution, preferably 1 g of polyvinylpyrrolidone per 100 mL of solution.

[0086] For example, the functional mixed enzyme solution of this application includes 50 mmol / L phosphate buffer, 0.05% Triton X-100, 1% trehalose, 1% PVA, 1% PVP, 5% potassium ferricyanide, and 1% glucose oxidase.

[0087] Figure 6 This is a planar schematic diagram of a functional enzyme membrane according to an embodiment of this application. Figure 7 This is a cross-sectional schematic diagram of a functional enzyme membrane according to an embodiment of this application, as shown below. Figures 6-7 As shown, due to the hygroscopic nature of polyvinylpyrrolidone, the functional enzyme layer will swell under prolonged exposure to high humidity, thus accelerating enzyme inactivation. Therefore, this application covers the functional enzyme membrane 140 with a bottom membrane 130, thereby reducing the pathway for moisture intrusion. Specifically:

[0088] The blood glucose test strip 100 further includes a bottom membrane 130, which does not include polyvinylpyrrolidone. The bottom membrane 130 is disposed on the side of the functional enzyme membrane 140 opposite to the hydrophilic membrane 150. The area of ​​the functional enzyme membrane 140 is smaller than the area of ​​the bottom membrane 130, and the orthographic projection of the bottom membrane 130 on the substrate 110 covers the orthographic projection of the functional enzyme membrane 140 on the substrate 110.

[0089] In simple terms, the orthographic projection of the bottom membrane 130 onto the substrate 110 completely covers the orthographic projection of the functional enzyme membrane 140 onto the substrate 110, causing the top cover 160 and the bottom membrane 130 to adhere to each other at the edge position. This reduces the path of moisture entering the functional enzyme membrane 140 from the side, thereby reducing the inactivation rate of the functional enzyme membrane 140 in a high humidity environment.

[0090] It should be noted that the limitations on each step involved in this solution are not considered as limiting the order of steps, provided that they do not affect the implementation of the specific solution. The steps listed first can be executed first, later, or even simultaneously. As long as this solution can be implemented, it should be considered to fall within the scope of protection of this application.

[0091] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0092] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A method for preparing a blood glucose test strip, characterized in that, The preparation method of the blood glucose test strip includes the following steps: S1: An electrode layer is formed on the substrate; S2: A functional mixed enzyme solution is disposed on the substrate and the electrode layer to form a functional enzyme membrane, wherein the functional mixed enzyme solution includes polyvinylpyrrolidone. S3: A hydrophilic membrane is disposed on the functional enzyme membrane; S4: A top cover is provided on the hydrophilic membrane to form the blood glucose test strip.

2. The method for preparing the blood glucose test strip according to claim 1, characterized in that, S1: The step of forming an electrode layer on the substrate includes: S11: The substrate is subjected to hydrophilic treatment to form a hydrophilic surface on one side of the substrate; S12: An electrode layer is formed on the hydrophilic surface of the substrate.

3. The method for preparing the blood glucose test strip according to claim 2, characterized in that, Step S2: The step of depositing a functional mixed enzyme solution on the substrate and the electrode layer to form a functional enzyme membrane, wherein the functional mixed enzyme solution includes polyvinylpyrrolidone, includes: S21: A bottom layer mixture is disposed on the hydrophilic surface of the substrate and the electrode layer, and pre-dried to form a bottom layer film; S22: A functional mixed enzyme solution is placed on the bottom layer membrane and completely dried to form a functional enzyme membrane. The functional mixed enzyme solution includes polyvinylpyrrolidone, while the bottom layer mixture does not contain polyvinylpyrrolidone.

4. The method for preparing the blood glucose test strip according to claim 3, characterized in that, In step S21: A bottom layer mixture is disposed on the hydrophilic surface of the substrate and the electrode layer, and pre-dried to form a bottom layer film. The water content of the bottom membrane is 0.5% to 10%.

5. A blood glucose test strip, characterized in that, The blood glucose test strip is prepared by the preparation method of blood glucose test strip as described in any one of claims 1-4 above. The blood glucose test strip includes a substrate, and an electrode layer, a functional enzyme membrane, a hydrophilic membrane and a top cover are sequentially disposed on the substrate. The functional enzyme membrane includes polyvinylpyrrolidone.

6. The blood glucose test strip according to claim 5, characterized in that, The blood glucose test strip also includes a bottom membrane, which does not include polyvinylpyrrolidone. The bottom membrane is disposed on the side of the functional enzyme membrane opposite to the hydrophilic membrane. The area of ​​the functional enzyme membrane is smaller than the area of ​​the bottom membrane, and the orthographic projection of the bottom membrane on the substrate covers the orthographic projection of the functional enzyme membrane on the substrate.

7. The blood glucose test strip according to claim 5, characterized in that, The molecular weight of the polyvinylpyrrolidone is 10,000 g / mol to 1,300,000 g / mol; the content of the polyvinylpyrrolidone is 0.01% to 5% (w / v).

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