Electrode for electrochemical glucose sensor based on patterned structure and method of preparation

Abstract

The application belongs to the field of glucose sensors, and discloses an electrode for an electrochemical glucose sensor based on a patterned structure and a preparation method, which comprises the following steps: preparing an island-bridge patterned structure ZnO film on a flexible substrate by using a screen printing process; and growing ZnO nanowires on the patterned structure ZnO film by using a water bath method to obtain the electrode for the electrochemical glucose sensor based on the patterned structure. The patterned structure ZnO film is used to improve the interfacial bonding force between the flexible substrate and the nanomechanical material, improve the lattice mismatch or electrostatic adsorption induced damage initiation and propagation zone between the sensor film layers, improve the surface tension and local stress-strain curve of the electrode under service conditions, finally realize the local stress controllability of the flexible electrode, improve the mechanical properties and structural strength of the film layer structure, improve the performance and structural stability of the electrochemical glucose sensor, and further improve the structural stability of the electrode under the action of external forces such as stretching, compression and torsion.

Description

Technical Field

[0001] This invention belongs to the field of glucose sensors, and relates to an electrode for an electrochemical glucose sensor based on a patterned structure and its preparation method. Background Technology

[0002] In the future of healthcare, "electrocardiogram and brain-computer interface" and "non-invasive portable health monitoring technology" have become two key technological breakthroughs. Real-time monitoring of blood glucose, blood lipids, blood pressure, and mood changes is crucial for improving human health and for early warning, prevention, and control of disease progression. Early detection, treatment, and prevention of diabetes are key to reducing the harm of this type of chronic disease. Therefore, it is necessary to develop wearable, real-time, non-invasive blood glucose monitoring systems to perform non-invasive, rapid, and accurate quantitative detection of blood glucose levels in the human body, addressing the urgent needs of diabetic patients for disease management and health monitoring.

[0003] Currently, common methods for blood glucose testing include optical, acoustic, fluorescence, electronic, capacitance, transdermal, and electrochemical methods. Among these, electrochemical methods have attracted much attention due to their advantages such as high sensitivity, simple principles, convenient operation, and the ability to be mass-produced.

[0004] The most commonly used device in electrochemical methods is the glucose sensor. Among the many glucose sensors, the performance of enzyme-based glucose sensors is greatly affected by the amount of enzyme adsorption, and they have high requirements for the detection environment and storage. Especially in the field of electrode development for flexible glucose sensors, the device is prone to enzyme shedding due to stretching, compression, and torsion in wearable environments, which in turn affects the detection performance and lifespan of the glucose sensor. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art, where the electrodes of flexible glucose sensors are prone to enzyme shedding due to stretching, compression and torsion in wearable environments, which affects the detection performance and service life of glucose sensors. This invention provides an electrode for an electrochemical glucose sensor based on a patterned structure and a method for its preparation.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a method for fabricating an electrode for an electrochemical glucose sensor based on a patterned structure, comprising:

[0008] ZnO thin films with island-bridge patterned structures were prepared on flexible substrates using screen printing.

[0009] ZnO nanowires were grown on a ZnO thin film with a patterned island-bridge structure using a water bath method to obtain a substrate with a patterned surface.

[0010] A substrate with a patterned surface is treated with glucose oxidase to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0011] Optionally, the fabrication of the ZnO thin film with island-bridge patterned structure on a flexible substrate using screen printing technology includes:

[0012] A copper mesh of a pre-defined specification is pasted and fixed onto a flexible substrate to obtain a pre-treated substrate;

[0013] A 50–150 nm gold film was sputtered onto a pretreated substrate, and then a ZnO seed layer was coated onto the pretreated substrate using a screen printing process to obtain a ZnO thin film with an island-bridge patterned structure.

[0014] Optionally, the specifications of the preset copper mesh are as follows:

[0015] The copper mesh has square or round holes; the mesh size is 50–200; the rib width is 15–60 μm; and the aperture is 75–300 μm.

[0016] Optionally, the process of applying a ZnO seed layer to the pretreated substrate using screen printing includes:

[0017] The prepared seed layer solution was uniformly coated on the pretreated substrate. After the seed layer solution dried, the copper mesh was removed to obtain a ZnO thin film with an island-bridge patterned structure.

[0018] Optionally, the seed layer solution is prepared in the following manner:

[0019] Add 1.098–2.196 g of zinc acetate solution to 60 ml of anhydrous ethanol and stir until dissolved to obtain a zinc acetate solution. Add 0.4–0.8 g of sodium hydroxide to 40 ml of anhydrous ethanol and stir until dissolved to obtain a sodium hydroxide solution. Then mix the zinc acetate solution and the sodium hydroxide solution to obtain a seed layer solution.

[0020] Optionally, the growth of ZnO nanowires on a patterned ZnO thin film using a water bath method includes:

[0021] Using Zn(NO3)2·6H2O and C6H 12 The growth stock solution was prepared using N6 and deionized water; wherein, the growth stock solution contained Zn 2+ At a concentration of 20–25 mM, Zn(NO3)2·6H2O and C6H 12 The molar ratio of N6 is 0.8 to 1:1;

[0022] The growth solution was heated to 80-95°C with stirring to obtain ZnO growth solution;

[0023] The substrate of ZnO thin film with island-bridge patterned structure was immersed in ZnO growth solution and placed in a water bath at a constant temperature of 80-95℃ to form a water bath growth environment for 2-3 hours.

[0024] Remove the substrate and let it air dry. Rinse the substrate surface repeatedly with deionized water to remove redundant ZnO nanorods. After allowing it to stand and dry again, a substrate with a patterned surface structure is obtained.

[0025] Optionally, the diameter of the ZnO nanowires is 50–150 nm.

[0026] Optionally, the glucose oxidase treatment of the substrate with the patterned surface includes:

[0027] A concentration of 30–40 mg / ml -1 A GOx solution was spin-coated onto the surface of a substrate with a patterned structure, and then naturally dried in air at 4–10°C to obtain a working electrode substrate modified with GOx.

[0028] A Nafion solution was coated onto a working electrode substrate modified with GOx to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0029] Optionally, the flexible substrate is a PET substrate.

[0030] In a second aspect, the present invention provides an electrode for an electrochemical glucose sensor based on a patterned structure, wherein the electrode for an electrochemical glucose sensor based on a patterned structure is prepared by the above-described method for preparing an electrode for an electrochemical glucose sensor based on a patterned structure.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention discloses a method for fabricating electrodes for electrochemical glucose sensors based on patterned structures. First, a ZnO thin film with an island-bridge patterned structure is prepared on a flexible substrate using screen printing. Then, ZnO nanowires are grown on the patterned ZnO thin film using a water bath method, ultimately obtaining an electrode with a patterned surface. The patterned ZnO thin film enhances the interfacial bonding between the flexible substrate and the nanomaterials, improving the damage initiation and propagation region caused by lattice mismatch or electrostatic adsorption between sensor film layers. Simultaneously, it improves the surface tension and local stress-strain curve of the electrode under service conditions, ultimately achieving controllable local stress in the flexible electrode. This improves the mechanical properties and structural strength of the film structure, enhancing the performance and structural stability of the electrochemical glucose sensor. Furthermore, it improves the structural stability of the electrode under tensile, compressive, and torsional forces, meeting the measurement requirements of the flexible electrode under service conditions. Moreover, this method for fabricating electrodes for electrochemical glucose sensors based on patterned structures offers significant advantages, including convenient fabrication, clear patterned structures, stable fabrication processes, and the ability to mass-produce, enabling rapid conduction of reactive charges in the electrochemical sensor. Attached Figure Description

[0033] Figure 1 This is a surface view of a pretreated substrate with a sputtered gold film according to an embodiment of the present invention;

[0034] Figure 2 This is a topographic image of the electrode for an electrochemical glucose sensor based on a patterned structure, according to an embodiment of the present invention.

[0035] Figure 3 This is a time-current response curve of an electrode for an electrochemical glucose sensor based on a graphical structure, according to an embodiment of the present invention.

[0036] Figure 4 The graph shows the current-glucose concentration response curve for testing the electrical performance of the electrode of the electrochemical glucose sensor based on a graphical structure, according to an embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram illustrating the change in sensing performance of an electrode for an electrochemical glucose sensor based on a patterned structure under bending external force conditions, according to an embodiment of the present invention.

[0038] Figure 6 This is a schematic diagram of the surface damage morphology of the electrode of the electrochemical glucose sensor based on a patterned structure according to an embodiment of the present invention under bending external force conditions. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] The present invention will now be described in further detail with reference to the accompanying drawings:

[0042] In one embodiment of the present invention, a method for fabricating an electrode for an electrochemical glucose sensor based on a patterned structure is provided. This method employs a composite process combining screen printing and a water bath method, achieving a novel and convenient method for fabricating electrodes with patterned surface structures. This enables rapid conduction of reactive charges in the electrochemical sensor, and the electrode exhibits good tensile, compressive, and torsional resistance. Specifically, the method for fabricating the electrode for an electrochemical glucose sensor based on a patterned structure includes the following steps:

[0043] Step 1: Prepare ZnO thin films with island-bridge patterned structures on flexible substrates using screen printing technology.

[0044] Step 2: ZnO nanowires are grown on the ZnO thin film with a patterned island-bridge structure using a water bath method to obtain a substrate with a patterned surface.

[0045] Step 3: Treat the substrate with a patterned surface with glucose oxidase to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0046] In one possible implementation, the preparation of the ZnO thin film with an island-bridge patterned structure on a flexible substrate using screen printing includes: attaching and fixing a copper mesh of a predetermined specification onto the flexible substrate to obtain a pretreated substrate; sputtering a gold film of 50-150 nm onto the pretreated substrate; and then applying a ZnO seed layer onto the pretreated substrate using screen printing to obtain the ZnO thin film with an island-bridge patterned structure.

[0047] The specifications of the copper mesh are as follows: the mesh is square or round; the mesh size is 50-200; the rib width is 15-60 μm; and the mesh diameter is 75-300 μm.

[0048] In one possible implementation, the process of applying a ZnO seed layer to a pretreated substrate using screen printing includes: uniformly applying a prepared seed layer solution to the pretreated substrate, waiting for the seed layer solution to dry, and then removing the copper screen to obtain a ZnO film with an island-bridge patterned structure.

[0049] The seed layer solution is prepared by adding 1.098–2.196 g of zinc acetate solution to 60 ml of anhydrous ethanol and stirring until dissolved to obtain a zinc acetate solution. Then, adding 0.4–0.8 g of sodium hydroxide solution to 40 ml of anhydrous ethanol and stirring until dissolved to obtain a sodium hydroxide solution. Finally, the zinc acetate solution and the sodium hydroxide solution are mixed to obtain the seed layer solution.

[0050] In one possible implementation, the growth of ZnO nanowires on a patterned ZnO thin film using a water bath method includes: using Zn(NO3)2·6H2O and C6H 12 The growth stock solution was prepared using N6 and deionized water; wherein, the growth stock solution contained Zn 2+ At a concentration of 20–25 mM, Zn(NO3)2·6H2O and C6H 12 The molar ratio of N6 is 0.8 to 1:1; the growth solution is heated to 80 to 95°C under stirring to obtain a ZnO growth solution; the substrate of the ZnO thin film with island-bridge patterned structure is immersed in the ZnO growth solution and placed in a water bath at a constant temperature of 80 to 95°C to form a water bath growth environment, and grown in the water bath for 2 to 3 hours; the substrate is taken out and dried, and the surface of the substrate is repeatedly rinsed with deionized water to remove redundant ZnO nanorods, and then allowed to stand and dry again to obtain a substrate with a patterned surface.

[0051] The diameter of the ZnO nanowires is 50–150 nm.

[0052] In one possible implementation, the glucose oxidase treatment of the substrate with the patterned surface comprises: applying a glucose oxidase at a concentration of 30–40 mg / ml. -1A GOx solution was spin-coated onto the surface of a substrate with a patterned structure, and then naturally dried in air at 4–10 °C to obtain a GOx-modified working electrode substrate. A Nafion solution was then coated onto the GOx-modified working electrode substrate to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0053] The following examples illustrate the method for preparing electrodes for an electrochemical glucose sensor based on a patterned structure according to the present invention.

[0054] Example 1

[0055] In one possible implementation, the method for fabricating the electrode for the electrochemical glucose sensor based on a patterned structure includes the following specific steps:

[0056] Step 1: A ZnO thin film with an island-bridge pattern was fabricated on a flexible substrate using screen printing. Specifically, the PET substrate was first cleaned and dried for later use; then, a 100nm gold film was sputtered onto the PET substrate to pre-treat and form a conductive substrate; finally, a copper mesh of a predetermined size was adhered to the PET substrate using AB adhesive. (See [link to AB adhesive]). Figure 1 The specifications of the selected copper mesh are as follows: the mesh shape is square; the mesh count is 100; the rib width is 30μm; and the mesh diameter is 230μm.

[0057] Because the copper mesh has square pores, the substrate structure has a square gold film patterned structure surface; then, a ZnO seed layer is coated on the PET substrate with the copper mesh attached using a screen printing process.

[0058] The process of applying a ZnO seed layer to a pretreated substrate using screen printing includes: tightly fixing and covering a copper mesh onto the substrate; uniformly applying a prepared seed layer solution onto the substrate with the copper mesh fixed on it; and removing the copper mesh after the seed layer solution has completely dried to obtain a substrate with a patterned surface.

[0059] The seed layer solution is prepared by adding 1.098g of zinc acetate solution to 60ml of anhydrous ethanol and stirring until dissolved to obtain a zinc acetate solution. Then, 0.4g of sodium hydroxide solution is added to 40ml of anhydrous ethanol and stirred until dissolved to obtain a sodium hydroxide solution. Finally, the zinc acetate solution and the sodium hydroxide solution are mixed to obtain the seed layer solution.

[0060] Step 2: ZnO nanowires were grown on the ZnO thin film with the island-bridge patterned structure using a water bath method. See [link to relevant documentation]. Figure 2 Electrodes for electrochemical glucose sensors based on patterned structures were obtained.

[0061] Specifically, Zn(NO3)2·6H2O and C6H 12 N6 was dissolved in 100 ml of deionized water to prepare the growth stock solution, in which Zn 2+ The concentration was set at 25 mM, with Zn(NO3)2·6H2O and C6H 12 The molar ratio of N6 is 1:1. The growth solution needs to be heated to 90℃ under magnetic stirring (1000 r·min⁻¹) to form a ZnO growth solution. The patterned substrate coated with the ZnO seed layer is immersed in the ZnO growth solution and placed in a water bath at a constant temperature of 90℃ to form a water bath growth environment. After 2.5 h of growth, the substrate is removed and air-dried at room temperature in an ultra-clean environment. Then, the substrate surface is repeatedly rinsed with deionized water to remove redundant ZnO nanorods. After being allowed to stand and dry again, a ZnONRs / Au / PET substrate with a patterned surface structure is obtained.

[0062] Step 3: Treat the substrate with a patterned surface with glucose oxidase to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0063] Specifically, the concentration is 40 mg / ml -1 A GOx solution was spin-coated onto the surface of a substrate with a patterned structure, and then air-dried at 4°C to obtain a GOx-modified working electrode substrate. A Nafion solution was then coated onto the GOx-modified working electrode substrate to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0064] Example 2

[0065] In one possible implementation, the method for fabricating the electrode for the electrochemical glucose sensor based on a patterned structure includes the following specific steps:

[0066] Step 1: Prepare a ZnO thin film with an island-bridge pattern on a flexible substrate using screen printing. Specifically, first, clean and dry the PET substrate for later use; then, place the PET substrate on a sputtering stage to sputter 50nm gold films to pre-treat and form a conductive substrate; finally, use AB adhesive to attach a copper mesh of a predetermined specification to the PET substrate. The specifications of the selected copper mesh are as follows: square aperture; 50 mesh; rib width; and aperture diameter.

[0067] Because the copper mesh has square pores, the substrate structure has a square gold film patterned structure surface; then, a ZnO seed layer is coated on the PET substrate with the copper mesh attached using a screen printing process.

[0068] The process of applying a ZnO seed layer to a pretreated substrate using screen printing includes: tightly fixing and covering a copper mesh onto the substrate; uniformly applying a prepared seed layer solution onto the substrate with the copper mesh fixed on it; and removing the copper mesh after the seed layer solution has completely dried to obtain a substrate with a patterned surface.

[0069] The seed layer solution is prepared by adding 1.647g of zinc acetate solution to 60ml of anhydrous ethanol and stirring until dissolved to obtain a zinc acetate solution. Then, 0.6g of sodium hydroxide is added to 40ml of anhydrous ethanol and stirred until dissolved to obtain a sodium hydroxide solution. Finally, the zinc acetate solution and the sodium hydroxide solution are mixed to obtain the seed layer solution.

[0070] Step 2: ZnO nanowires are grown on a ZnO thin film with an island-bridge patterned structure using a water bath method to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0071] Specifically, Zn(NO3)2·6H2O and C6H 12 N6 was dissolved in 100 ml of deionized water to prepare the growth stock solution, in which Zn 2+ The concentration was set at 20 mM, Zn(NO3)2·6H2O and C6H 12 The molar ratio of N6 is 0.8:1. The growth solution needs to be heated to 80℃ under magnetic stirring (1000 r·min⁻¹) to form a ZnO growth solution. The patterned substrate coated with the ZnO seed layer is immersed in the ZnO growth solution and placed in a water bath at a constant temperature of 80℃ to form a water bath growth environment. After 2 hours of growth, the substrate is removed and air-dried at room temperature in an ultra-clean environment. Then, the substrate surface is repeatedly rinsed with deionized water to remove redundant ZnO nanorods. After being allowed to stand and dry again, a ZnONRs / Au / PET substrate with a patterned surface structure is obtained.

[0072] Step 3: Treat the substrate with a patterned surface with glucose oxidase to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0073] Specifically, the concentration is 30 mg / ml -1 A GOx solution was spin-coated onto the surface of a substrate with a patterned structure, and then air-dried at 8°C to obtain a GOx-modified working electrode substrate. A Nafion solution was then coated onto the GOx-modified working electrode substrate to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0074] Example 3

[0075] In one possible implementation, the method for fabricating the electrode for the electrochemical glucose sensor based on a patterned structure includes the following specific steps:

[0076] Step 1: Prepare a ZnO thin film with an island-bridge pattern on a flexible substrate using screen printing. Specifically, first, clean and dry the PET substrate for later use; then, send the PET substrate to a sputtering stage to sputter a 150nm gold film to pre-treat and form a conductive substrate; finally, use AB adhesive to attach a copper mesh of a predetermined specification to the PET substrate. The specifications of the selected copper mesh are as follows: square aperture; 200 mesh; rib width; and aperture diameter.

[0077] Because the copper mesh has square pores, the substrate structure has a square gold film patterned structure surface; then, a ZnO seed layer is coated on the PET substrate with the copper mesh attached using a screen printing process.

[0078] The process of applying a ZnO seed layer to a pretreated substrate using screen printing includes: tightly fixing and covering a copper mesh onto the substrate; uniformly applying a prepared seed layer solution onto the substrate with the copper mesh fixed on it; and removing the copper mesh after the seed layer solution has completely dried to obtain a substrate with a patterned surface.

[0079] The seed layer solution is prepared by adding 2.196g of zinc acetate solution to 60ml of anhydrous ethanol and stirring until dissolved to obtain a zinc acetate solution. Then, 0.8g of sodium hydroxide is added to 40ml of anhydrous ethanol and stirred until dissolved to obtain a sodium hydroxide solution. Finally, the zinc acetate solution and the sodium hydroxide solution are mixed to obtain the seed layer solution.

[0080] Step 2: ZnO nanowires are grown on a ZnO thin film with an island-bridge patterned structure using a water bath method to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0081] Specifically, Zn(NO3)2·6H2O and C6H 12 N6 was dissolved in 100 ml of deionized water to prepare the growth stock solution, in which Zn 2+ The concentration was set at 20 mM, Zn(NO3)2·6H2O and C6H 12The molar ratio of N6 is 1:1. The growth solution needs to be heated to 95°C under magnetic stirring (1000 r·min⁻¹) to form a ZnO growth solution. The patterned substrate coated with the ZnO seed layer is immersed in the ZnO growth solution and placed in a water bath at a constant temperature of 95°C to form a water bath growth environment. After 3 hours of growth, the substrate is removed and air-dried at room temperature in an ultra-clean environment. Then, the substrate surface is repeatedly rinsed with deionized water to remove redundant ZnO nanorods. After being allowed to stand and dry again, a ZnONRs / Au / PET substrate with a patterned surface structure is obtained.

[0082] Step 3: Treat the substrate with a patterned surface with glucose oxidase to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0083] Specifically, the concentration is 35 mg / ml -1 A GOx solution was spin-coated onto the surface of a substrate with a patterned structure, and then air-dried at 10°C to obtain a GOx-modified working electrode substrate. A Nafion solution was then coated onto the GOx-modified working electrode substrate to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

[0084] In one possible implementation, the glucose response of the fabricated electrochemical glucose sensor electrode based on a patterned structure is tested using a chronoamperometry method.

[0085] The test employed a three-electrode system on a CHI660 electrochemical workstation. The operating voltage was set to 0.8V. The counter electrode (Pt), reference electrode (Ag / AgCl), and the electrode prepared according to this invention were immersed in 50ml of PBS buffer (detection cell). A rotor was added to the buffer, and the rotor speed was set to 150 rpm. After power-on and initialization for 40 minutes, once the it curve stabilized, 600 μL of 1mM / L glucose solution was injected into the detection cell every 30 minutes, increasing the glucose concentration in increments of 0.012 mM / L. Under suitable conditions, the linear response of the electrode to glucose ranged from 0.012 mM / L to 0.096 mM / L, with a correlation coefficient r = 0.99 and a response sensitivity of 25.74 μA·(mM / L). -1 The test results are as follows: Figure 3 and Figure 4 As shown.

[0086] In one possible implementation, stress-strain tests are performed on the electrodes of the electrochemical glucose sensor based on the patterned structure to study their failure modes under extreme external forces, and to investigate the intrinsic relationship between the failure modes of the working electrode fabrication process, thereby obtaining a theoretical analysis model of the bonding strength between the fabrication process and the film layer.

[0087] See Figure 5 Under the same bending mechanical test, the surface morphology and performance change trend of the electrode for the electrochemical glucose sensor based on the patterned structure were quantitatively characterized. In terms of performance change, when the electrode for the electrochemical glucose sensor based on the patterned structure was bent 10 times under the same mechanical action, its performance was about 97.4% of the initial value. When it was bent about 15 times, the performance decreased to 78% of the initial value. When it was bent 20 times, the performance decayed to 67.1% of the initial value. When it was bent 25 times, the performance was only 16.2% of the initial value.

[0088] See Figure 6 Based on laboratory testing data, the surface morphology of the electrode for the patterned electrochemical glucose sensor after 10 bends was observed using SEM. Island-like cracks appeared in the ZnO nanowire film, with localized detachment at the crack junctions. This indicates that the electrode for the patterned electrochemical glucose sensor can maintain detection performance comparable to its initial value under external force. However, with increased service life and increasing external force, the functional building blocks suffer varying degrees of damage, leading to a decrease in sensor performance, although the rate of decrease is non-linear.

[0089] In summary, this invention addresses the relationship between the damage morphology of the sensor's working electrode structure and its performance degradation. By constructing a stability characteristic model of the "film layer" structure and analyzing its damage mechanism, a feasible solution is derived to enhance the interfacial bonding between the substrate and nanomaterials using patterned working electrodes. This improves the damage initiation and propagation region caused by lattice mismatch or electrostatic adsorption between sensor film layers. Through optimized design, a patterned working electrode surface with an island-bridge structure is fabricated. The patterned design improves the surface tension and local stress-strain curves of the working electrode under service conditions. The implementation of this invention enables controllable local stress in flexible working electrodes, improves the mechanical properties and structural strength of the film layer structure, and further enhances the performance and structural stability of the electrochemical glucose sensor.

[0090] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for fabricating an electrode for an electrochemical glucose sensor based on a patterned structure, characterized in that, include: A ZnO thin film with an island-bridge patterned structure is prepared on a flexible substrate using a screen printing process. The process includes: attaching and fixing a copper mesh of a predetermined size onto a flexible substrate to obtain a pretreated substrate; sputtering a gold film of 50-150 nm onto the pretreated substrate; and then applying a ZnO seed layer onto the pretreated substrate using a screen printing process to obtain a ZnO thin film with an island-bridge patterned structure. ZnO nanowires were grown on a ZnO thin film with a patterned island-bridge structure using a water bath method to obtain a substrate with a patterned surface. A substrate with a patterned surface is treated with glucose oxidase to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

2. The method for preparing an electrode for an electrochemical glucose sensor based on a patterned structure according to claim 1, characterized in that, The specifications of the copper mesh of the preset standard are as follows: The copper mesh has square or round holes; the mesh size is 50-200; the rib width is 15-60μm; and the aperture is 75-300μm.

3. The method for fabricating an electrode for an electrochemical glucose sensor based on a patterned structure according to claim 1, characterized in that, The process of applying a ZnO seed layer to the pretreated substrate using screen printing includes: The prepared seed layer solution was uniformly coated on the pretreated substrate. After the seed layer solution dried, the copper mesh was removed to obtain a ZnO thin film with an island-bridge patterned structure.

4. The method for preparing an electrode for an electrochemical glucose sensor based on a patterned structure according to claim 3, characterized in that, The seed layer solution was prepared in the following manner: Add 1.098~2.196g of zinc acetate solution to 60ml of anhydrous ethanol and stir until dissolved to obtain zinc acetate solution. Add 0.4~0.8g of sodium hydroxide to 40ml of anhydrous ethanol and stir until dissolved to obtain sodium hydroxide solution. Then mix the zinc acetate solution and sodium hydroxide solution to obtain seed layer solution.

5. The method for fabricating an electrode for an electrochemical glucose sensor based on a patterned structure according to claim 1, characterized in that, The growth of ZnO nanowires on patterned ZnO films using a water bath method includes: Using Zn(NO3)2·6H2O and C6H 12 The growth stock solution was prepared using N6 and deionized water; wherein, the growth stock solution contained Zn 2+ At a concentration of 20-25 mM, Zn(NO3)2·6H2O and C6H 12 The molar ratio of N6 is 0.8~1:1; The growth solution was heated to 80-95℃ with stirring to obtain ZnO growth solution; The substrate of ZnO thin film with island-bridge patterned structure was immersed in ZnO growth solution and placed in a water bath at a constant temperature of 80~95℃ to form a water bath growth environment for 2~3 hours. Remove the substrate and let it air dry. Rinse the substrate surface repeatedly with deionized water to remove redundant ZnO nanorods. After allowing it to stand and dry again, a substrate with a patterned surface structure is obtained.

6. The method for fabricating an electrode for an electrochemical glucose sensor based on a patterned structure according to claim 5, characterized in that, The diameter of the ZnO nanowires is 50~150nm.

7. The method for preparing an electrode for an electrochemical glucose sensor based on a patterned structure according to claim 1, characterized in that, The process of treating the substrate with a patterned surface using glucose oxidase includes: A concentration of 30~40 mg·ml -1 The GOx solution was spin-coated onto the surface of a substrate with a patterned structure, and then naturally dried in air at 4~10℃ to obtain a working electrode substrate modified with GOx. A Nafion solution was coated onto a GOx-modified working electrode substrate to obtain an electrode for an electrochemical glucose sensor based on a patterned structure.

8. The method for fabricating an electrode for an electrochemical glucose sensor based on a patterned structure according to claim 1, characterized in that, The flexible substrate is a PET substrate.

9. An electrode for an electrochemical glucose sensor based on a patterned structure, characterized in that, The electrode for the electrochemical glucose sensor based on the patterned structure is prepared by the method for preparing the electrode for the electrochemical glucose sensor based on the patterned structure according to any one of claims 1 to 8.

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