Manufacturing method of implantable biological electrode and implantable glucose monitoring probe

Abstract

The invention relates to an implantable biological electrode and a manufacturing method of an implantable glucose monitoring probe. The manufacturing method of the implantable biological electrode comprises the following steps: S1.1, providing a flexible substrate; s1.2, silk-screening silver ink on the first surface of the flexible substrate to form a non-implanted conductive region of the first functional electrode; s1.3, silk-screening carbon ink on the first surface of the flexible substrate to form an implanted conductive region of the first functional electrode, and forming a series structure by the non-implanted conductive region and the implanted conductive region to jointly form a conductive region of the first functional electrode; and S1.4, an insulating layer is screen-printed on the first surface of the flexible substrate, the insulating layer covers the conductive region of the first functional electrode, and the working region is exposed. According to the functional electrode, the characteristic of good biocompatibility of the carbon circuit layer and the characteristics of small resistance and high signal transmission efficiency of the silver circuit layer are fully utilized, the circuit impedance of the functional electrode is effectively reduced, the signal transmission efficiency is improved, and the biocompatibility and long-term stability of an implantation area are ensured.

Description

Technical Field

[0001] The present application relates to the technical field of biosensors, and in particular to a method for manufacturing an implantable bioelectrode and an implantable glucose monitoring probe. Background Art

[0002] As the incidence of diabetes continues to rise, the demand for real-time and accurate blood glucose monitoring is growing. As an efficient diabetes management tool, the implantable continuous glucose monitoring (CGM) system has become the focus of market attention. The CGM system usually relies on an implantable monitoring probe to electrochemically detect the glucose concentration in tissue fluid or blood. The monitoring probe includes a probe sensor, which is usually composed of a working electrode, a reference electrode and a counter electrode. The detection mechanism is based on the current signal generated by the redox reaction between glucose oxidase and glucose. In the prior art, the electrode structure design of the implantable glucose monitoring probe is its core part. The material and structural design of the working electrode, reference electrode and counter electrode directly determine the electrochemical performance and biocompatibility of the monitoring probe, which in turn directly affects the sensitivity, stability and anti-interference performance of the monitoring probe.

[0003] The Chinese patent application with publication number CN112710713A discloses an implantable glucose monitoring probe, the materials and structural designs of its working electrode, reference electrode and counter electrode all have certain technical advantages. The working electrode is usually made of highly conductive materials, such as gold, glassy carbon, graphite, silver or platinum, and coated on its surface with a porous nanoparticle layer that catalyzes the glucose reaction. These particle layers are composed of platinum, titanium, gold or carbon materials, which significantly improve the specific surface area and catalytic performance of the electrode, thereby reducing the catalytic potential of the working electrode; the reference electrode generally uses stable materials such as silver chloride or platinum to form a fixed potential difference with tissue fluid or blood, providing an accurate reference potential for the working electrode; the counter electrode is made of platinum or silver to ensure the efficient closure of the electrochemical circuit. These three electrodes are arranged side by side and adopt a separate layout, which helps to reduce interference between electrodes and enhance the detection stability of the signal.

[0004] A Chinese patent application with publication number CN109765286A discloses a continuous glucose monitoring system sensor and a method for manufacturing the same, wherein conductive layers and insulating layers are alternately stacked on a substrate in a preset order, wherein the conductive layers and insulating layers are made of biocompatible materials; holes are opened in preset areas to obtain holes, wherein the inner walls of the holes expose the corresponding conductive layers, and the inner walls of each of the holes are in contact with only one conductive layer; an enzyme layer is set in the holes obtained after the holes are opened, and the enzyme layer is used to react with glucose to generate current; a membrane layer is set in the holes where the enzyme layer is set, and the membrane layer is permeable to glucose. In this design, three electrodes are stacked to save space.

[0005] However, the above existing technologies still have many limitations in practical applications: 1. The multiple functional electrodes of the probe can be made of materials such as carbon, metal platinum or silver. Metal platinum and silver have low resistance and high signal transmission efficiency, but these metal materials have poor biocompatibility, strong foreign body sensation after implantation, which can easily cause discomfort to patients and have poor adaptability. Carbon has good biocompatibility, weak foreign body sensation after implantation and good adaptability, but carbon has high resistance and low signal transmission efficiency, which will weaken the sensitivity of electrical signals and affect the sensitivity and detection accuracy of blood glucose detection. In addition, if metal impurities (such as silver) are doped in the carbon material, it is easy to generate stray peaks during the electrochemical test, which interferes with the normal signal output of the working electrode and reduces the detection accuracy and stability of the sensor.

[0006] 2. The porous nanoparticle layer often set in the working electrode is one of the keys to improve the electrochemical performance. These nanoparticle layers are usually made of materials such as platinum, carbon nanotubes, gold or graphene, which can not only significantly increase the reaction specific surface area of ​​the electrode, but also catalyze glucose oxidation reaction, effectively reduce the working voltage, and enhance the fixation effect of glucose enzyme. In the prior art, the enzyme modification method mainly adopts the pull-up dip coating method or the coating method. These methods are simple to operate, but the uniformity of electrode surface coating is insufficient. The pull-up dip coating method depends on parameters such as the pulling speed and solution viscosity, resulting in uneven distribution of the enzyme on the electrode surface, and the existence of local concentrations that are too high or too low; and although the coating method has a larger coverage range, it is also difficult to ensure the uniformity of the enzyme layer distribution due to the influence of the coating equipment precision and the electrode surface roughness, which easily causes the waste of enzyme materials. This unevenness also makes the enzyme catalytic efficiency in some electrode areas low, and may even cause signal instability. At the same time, since these processes are mainly based on physical adsorption, the enzymes have weak adhesion and are easily detached during long-term use, especially under the influence of body fluid flushing or mechanical vibration. This further reduces the enzyme catalytic efficiency and affects the service life and stability of the monitoring probe.

[0007] 3. The existing probes lack effective interference shielding design, the electrode structure has weak anti-interference ability, and are easily interfered by impurities in the body such as uric acid and ascorbic acid, resulting in large errors in the test results and insufficient stability.

[0008] 4. The contact area where the functional electrode contacts the external electronic device is prone to wear: The contact design of existing CGM devices generally uses soft carbon or ordinary metal materials, which are easily affected by plugging and unplugging or environmental oxidation during use, resulting in contact wear and performance degradation, thereby shortening the service life of the monitoring probe.

[0009] 5. The structural fixation of the monitoring probe is poor: Some CGM devices rely on flexible materials for fixation or adhesion, lack an effective fixed installation design, and are prone to loosening during implantation or long-term use, affecting the reliability of the connection between the functional electrode and the external device.

[0010] 6. The impact of interference is large: Some technologies fail to effectively block the interference of non-glucose substances, resulting in large signal deviations and difficulty in obtaining stable blood glucose test results. Summary of the invention

[0011] In order to solve the technical problem in the prior art that the bioelectrode for implantable biological monitoring probe uses a carbon circuit layer, which leads to high resistance, low signal transmission efficiency, weakened sensitivity of electrical signals, and affects the sensitivity and detection accuracy of the monitoring probe, the present invention provides a method for manufacturing an implantable bioelectrode and a method for manufacturing an implantable glucose monitoring probe.

[0012] On the one hand, the technical solution provided by the present application is as follows: a method for manufacturing an implantable bioelectrode, wherein the implantable bioelectrode comprises a flexible substrate and a first functional electrode, wherein the first functional electrode comprises a conductive area and a working area, wherein the conductive area is further divided into a non-implanted conductive area and an implanted conductive area, and comprises the following steps: S1.1, providing a flexible substrate; S1.2, screen printing silver ink on the first surface of the flexible substrate, and drying and curing the ink to form a non-implanted conductive area of ​​the first functional electrode; S1.3, screen printing carbon ink on the first surface of the flexible substrate, and drying and curing the ink to form an implanted conductive area of ​​the first functional electrode, wherein the non-implanted conductive area and the implanted conductive area form a series structure to form a conductive area of ​​the first functional electrode; S1.4, screen-printing an insulating layer on the first surface of the flexible substrate and curing the layer, wherein the insulating layer covers the conductive area of ​​the first functional electrode and exposes the working area.

[0013] Preferably, the implantable bioelectrode also includes a second functional electrode, and after step S1.4, it also includes step S1.5, screen printing silver ink on the first surface of the flexible substrate, and drying and curing it to form a non-implanted conductive area of ​​the second functional electrode; S1.6, screen printing carbon ink on the first surface of the flexible substrate, and drying and curing it to form an implanted conductive area of ​​the second functional electrode, the non-implanted conductive area and the implanted conductive area form a series structure, and together form a conductive area of ​​the second functional electrode.

[0014] Preferably, in step S1.2, the first detection point of the first functional electrode is also screen-printed synchronously, and the first detection point of the first functional electrode is located at the outer end of the non-implanted conductive area of ​​the first functional electrode; in step S1.3, the second detection point of the first functional electrode is also screen-printed synchronously, and the second detection point of the first functional electrode is located at the outer end of the implanted conductive area of ​​the first functional electrode; after the test is completed, the first detection point and the second detection point are cut or removed.

[0015] Preferably, in step S1.3, a carbon material purity detection electrode is simultaneously screen-printed on a blank area of ​​the first surface of the flexible substrate to perform an electrochemical performance test.

[0016] Preferably, in step S1.2, the thickness of the silver ink is 10-50 μm, the drying temperature is 120-150° C., and the time is 5-10 minutes; in step S1.3, the thickness of the carbon ink is 10-50 μm, the drying temperature is 90-120° C., and the time is 8-12 minutes.

[0017] Preferably, the material of the insulating layer is a UV light-curing insulating layer, which is cured by UV light irradiation. The thickness of the insulating layer is 5-20 μm, the wavelength of the UV light source is 365 nm, the energy intensity is 100-150 mJ / cm², and the irradiation time is 10-30 seconds.

[0018] On the other hand, the present application also provides the following technical solutions: a method for manufacturing an implantable glucose monitoring probe, the glucose monitoring probe comprising a flexible substrate, a working electrode, a reference electrode, a counter electrode and a multi-layer insulating layer, the working electrode and the reference electrode are stacked from the inside to the outside on the front side of the flexible substrate, the counter electrode is arranged on the back side of the flexible substrate, the insulating layer is arranged between the working electrode and the reference electrode to achieve interlayer isolation, and is arranged on the outer surface of the reference electrode and the counter electrode to play an insulating protection role, the working electrode, the reference electrode and the counter electrode all include a conductive area and a working area, the conductive area and the working area are electrically connected, the conductive area includes an implanted conductive area implanted in the human body and a non-implanted conductive area not implanted in the human body, the working areas of the working electrode and the reference electrode are provided with sensitive materials, and the implanted conductive area of ​​the counter electrode is the working area, comprising the following steps: S2.1, provide a full sheet of flexible substrate material; S2.2, screen printing a non-implanted conductive area of ​​the counter electrode on the back side of the flexible substrate material, the material being silver ink, and then drying and curing; S2.3, screen printing the implanted conductive area of ​​the counter electrode on the back side of the flexible substrate material, the material is carbon ink, and then drying and curing, the non-implanted conductive area and the implanted conductive area of ​​the counter electrode form a series structure, and together form a conductive area of ​​the counter electrode; S2.4, screen printing an insulating layer on the back side of the flexible substrate material, and then curing it, wherein the insulating layer covers the non-implanted conductive area of ​​the counter electrode, exposing the working area; S2.5, turning over the flexible substrate material, screen-printing the non-implanted conductive area of ​​the working electrode on the front side of the flexible substrate material, the material being silver ink, and then drying and curing; S2.6, screen printing the implanted conductive area of ​​the working electrode on the front side of the flexible substrate material, the material is carbon ink, and then drying and curing; S2.7, screen printing a first insulating layer on the front side of the flexible substrate material, and then curing the first insulating layer, wherein the first insulating layer covers the conductive area of ​​the working electrode and a part of the flexible substrate, so that the working electrode and the reference electrode are isolated from each other; S2.8, screen printing a non-implanted conductive area of ​​a reference electrode on the front side of the flexible substrate material, the material being silver ink, and then drying and curing; S2.9, screen printing the implanted conductive area of ​​the reference electrode on the front side of the flexible substrate material, the material being carbon ink, and then drying and curing; S2.10, screen printing a second insulating layer on the front side of the flexible substrate material, and then curing the second insulating layer, wherein the second insulating layer covers most of the conductive area of ​​the reference electrode, exposing the working area of ​​the reference electrode; S2.11, screen printing the sensitive material on the working area of ​​the reference electrode, and then drying and curing it, so that the sensitive material is electrically connected to the conductive area of ​​the reference electrode; S2.12, screen printing a sensitive material on the working area of ​​the working electrode, and then drying and curing the sensitive material, so that the sensitive material is electrically connected to the conductive area of ​​the working electrode; S2.13, processing array micropores in the working area of ​​the working electrode to provide a precise area for the attachment of the enzyme layer; S2.14, making an enzyme layer, using an enzyme spotting machine to precisely spot the enzyme material in the microwells of the array; S2.15, coating a biocompatible film on the working area of ​​the working electrode to cover the enzyme layer; S2.16, the tails of the working electrode, reference electrode and counter electrode are contact areas, and an anti-oxidation coating is applied to the contact areas; S2.17, using a laser engraving process to accurately engrave the shape of the glucose monitoring probe, as well as the shapes of the working electrode, the reference electrode, and the counter electrode; S2.18, dividing the entire plate of glucose monitoring probes into monomeric glucose monitoring probes.

[0019] Preferably, in step S2.1, an array of conductive through holes is produced on a whole sheet of flexible substrate material; in step S2.2, silver ink is introduced into the conductive through holes; in step S2.5, a contact area for the counter electrode is also produced simultaneously, the contact area for the counter electrode is electrically connected to the counter electrode through the conductive through holes, and the contact area for the counter electrode is transferred to the front side of the flexible substrate material.

[0020] Preferably, in step S2.1, conductive through holes are made on the entire flexible substrate material using a microsecond laser engraving device, and the diameter of the conductive through holes is 50-100 μm; in step S2.13, array micropores are processed in the working area of ​​the working electrode using an ultraviolet picosecond laser processing device, and the diameter of the array micropores is 20-100 μm and the depth is 0.5-5 μm; in step S2.17, laser engraving is performed using an ultraviolet picosecond laser processing device.

[0021] Preferably, in steps S2.3, S2.6 and S2.9, carbon material purity detection electrodes are simultaneously produced in blank spaces of the entire page of flexible substrate material; in step S2.3, the first detection point of the counter electrode is simultaneously produced, in step S2.5, the first detection point of the working electrode and the second detection point of the counter electrode are simultaneously produced, in step S2.6, the second detection point of the working electrode is simultaneously produced, in step S2.8, the first detection point of the reference electrode is simultaneously produced, and in step S2.9, the second detection point of the reference electrode is simultaneously produced; in step S2.17, the first detection point and the second detection point of the counter electrode, the working electrode and the reference electrode are cut off or cleared.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. The present application divides the conductive area of ​​the first functional electrode into two parts, an implanted conductive area implanted in the human body and a non-implanted conductive area not implanted in the human body. The implanted conductive area is a carbon circuit layer, and the non-implanted conductive area is a silver circuit layer. The carbon circuit layer has good biocompatibility and the silver circuit layer has low resistance and high signal transmission efficiency. The circuit impedance of the functional electrode is effectively reduced, the signal transmission efficiency is improved, and the biocompatibility and long-term stability of the implanted area are ensured. The silver circuit layer and the carbon circuit layer form a series structure to ensure the passage of the conductive area.

[0023] 2. Both the carbon circuit layer and the silver circuit layer can be produced using silk screen printing technology, and combined with CCD automatic capture point technology, it can ensure high precision of position, shape and thickness, and effectively reduce short circuits, circuit breaks or discontinuities caused by traditional processes.

[0024] 3. This application has designed a synchronous detection point solution, which uses automated detection equipment to detect resistance values, conductivity and short circuit conditions. This process realizes non-destructive testing of mass production, achieves the purpose of quality control, and improves production yield and consistency.

[0025] 4. The present application can utilize the carbon material purity detection electrode to detect the purity of the carbon material through automated detection equipment, and conduct electrochemical performance testing (such as CV curve testing) to eliminate the interference of impurities in the carbon material, effectively eliminate the interference of miscellaneous peaks in the electrochemical test, and improve the purity of the electrochemical signal and the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the action of screen printing the non-implanted conductive area of ​​the first functional electrode onto the flexible substrate in the method for manufacturing the implantable laminated probe according to the first embodiment of the present application is depicted; Figure 2 A schematic diagram of the process of screen printing the implanted conductive region of the first functional electrode onto the flexible substrate in the method for manufacturing the implantable laminated probe according to the first embodiment of the present application is depicted; Figure 3 A schematic diagram of the action of screen printing an insulating layer onto a flexible substrate in a method for manufacturing an implantable laminated probe according to a first embodiment of the present application is depicted; Figure 4 A schematic diagram of the action of coating the anti-oxidation coating on the first functional electrode contact layer in the method for manufacturing an implantable laminated probe according to the first embodiment of the present application is depicted; Figure 5 A schematic diagram of the process of screen-printing the non-implanted conductive area of ​​the first functional electrode and the first detection point of the first functional electrode onto the flexible substrate in the method for manufacturing the implantable laminated probe according to the second embodiment of the present application is depicted; Figure 6 A schematic diagram of the process of screen-printing the implanted conductive area of ​​the first functional electrode and the second detection point of the first functional electrode onto the flexible substrate in the method for manufacturing the implantable laminated probe according to the second embodiment of the present application is depicted; Figure 7 A schematic diagram of the action of screen printing an insulating layer onto a flexible substrate in the method for manufacturing an implantable laminated probe according to the second embodiment of the present application is depicted; Figure 8 A schematic diagram of the process of screen-printing the non-implanted conductive area of ​​the second functional electrode and the first detection point of the second functional electrode onto the flexible substrate in the method for manufacturing the implantable laminated probe according to the second embodiment of the present application is depicted; Fig. 9A schematic diagram of the process of screen-printing the implanted conductive area of ​​the second functional electrode and the second detection point of the second functional electrode onto the flexible substrate in the method for manufacturing the implantable laminated probe according to the second embodiment of the present application is depicted; Fig.10 A schematic diagram of the process of screen-printing the implanted conductive region of the first functional electrode and the carbon material purity detection electrode onto the flexible substrate in the method for manufacturing the implantable laminated probe in the third embodiment of the present application is depicted; Fig.11 A schematic diagram of the process of screen-printing the non-implanted conductive region of the counter electrode onto the back of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to an embodiment of the present application is depicted; Fig.12 A schematic diagram of the process of screen-printing the implanted conductive area of ​​the counter electrode and the first detection point of the counter electrode on the back of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.13 A schematic diagram of the action of screen printing an insulating layer onto the back of a flexible substrate in the method for manufacturing an implantable glucose monitoring probe according to an embodiment of the present application is depicted; Fig.14 A schematic diagram of the process of screen-printing the non-implanted conductive area of ​​the working electrode, the first detection point of the working electrode, the contact area of ​​the counter electrode and the second detection point of the counter electrode on the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.15 A schematic diagram of the process of screen-printing the implanted conductive area of ​​the working electrode and the second detection point of the working electrode on the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.16 A schematic diagram of the action of screen-printing the first insulating layer onto the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.17 A schematic diagram of the process of screen-printing the non-implanted conductive area of ​​the reference electrode and the first detection point of the reference electrode on the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.18 A schematic diagram of the process of screen-printing the implanted conductive area of ​​the reference electrode and the second detection point of the reference electrode on the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.19 A schematic diagram of the action of screen-printing the second insulating layer onto the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig. 20 A schematic diagram of the process of screen-printing the sensitive material of the reference electrode onto the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.21A schematic diagram of the process of screen printing the sensitive material of the working electrode onto the front side of the flexible substrate in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig. 22 A schematic diagram of processing the array micropores in the working area of ​​the working electrode in the method for manufacturing the implantable glucose monitoring probe according to the embodiment of the present application is depicted; Fig.23 A schematic diagram of filling an enzyme layer in the display microwells in the method for making an implantable glucose monitoring probe according to an embodiment of the present application is depicted; Fig.24 A schematic diagram of the action of silk-screening an anti-oxidation coating on the contact area of ​​a counter electrode, a working electrode and a reference electrode in the method for manufacturing an implantable glucose monitoring probe according to an embodiment of the present application is depicted; Fig.25 A schematic diagram of the structure after all detection points are cut off in the method for making an implantable glucose monitoring probe according to an embodiment of the present application is depicted; Fig.26 A schematic diagram of the exploded structure of each component in the process of manufacturing the implantable glucose monitoring probe according to an embodiment of the present application is depicted; Fig. 27 A schematic diagram of the exploded structure of each component after final engraving in the method for manufacturing an implantable glucose monitoring probe according to an embodiment of the present application is depicted.

[0027] Explanation of reference numerals: 1. flexible substrate; 11. conductive through hole; 12. plug-in buckle fixing structure; 2. first functional electrode; 21. conductive area; 211. implanted conductive area; 212. non-implanted conductive area; 213. contact area; 22. working area; 23. first detection point; 24. second detection point; 3. second functional electrode; 31. conductive area; 311. implanted conductive area; 312. non-implanted conductive area; 313. contact area; 32. working area; 33. first detection point; 34. second detection point; 4. insulating layer; 5. anti-oxidation coating; 6. carbon material purity detection electrode; 7. working area as electrode; 71, conductive area; 711, implanted conductive area; 712, non-implanted conductive area; 713, contact area; 72, working area; 721, micropore array; 73, first detection point; 74, second detection point; 8, reference electrode; 81, conductive area; 811, implanted conductive area; 812, non-implanted conductive area; 82, working area; 83, contact area; 84, first detection point; 85, second detection point; 9, counter electrode; 91, conductive area; 911, implanted conductive area; 912, non-implanted conductive area; 92, contact area; 93, first detection point; 94, second detection point; 10, enzyme layer. DETAILED DESCRIPTION

[0028] The following is combined with Figures 1 to 27 This application is described in further detail.

[0029] Embodiment 1: Reference Figures 1 to 4 This embodiment discloses a method for manufacturing an implantable bioelectrode, wherein the implantable bioelectrode comprises a flexible substrate 1 and a first functional electrode 2, wherein the first functional electrode 2 comprises a conductive area 21 and a working area 22, wherein the conductive area 21 is further divided into a non-implanted conductive area 212 and an implanted conductive area 211, wherein the tail end of the non-implanted conductive area 212 is used for making electrical contact with an external electronic device, so it is also referred to as a contact area 213, and the implantable bioelectrode is suitable for use as a detection electrode of a plug-in rapid detection device, such as an implantable continuous glucose monitoring probe, with reference to Figure 1 The flexible substrate 1 is also provided with plug-in buckle fixing structures 12 on both sides of the tail for quick installation and removal with external electronic devices. The manufacturing method comprises the following steps: S1.1, providing a flexible substrate 1.

[0030] S1.2, refer to Figure 1 , silver ink is screen-printed on the first surface of the flexible substrate 1, and dried and cured to form the non-implanted conductive area 212 of the first functional electrode 2; the preferred thickness of the silver ink is 10-50 μm, the drying temperature is 120-150° C., and the drying time is 5-10 minutes.

[0031] S1.3, refer to Figure 2 , carbon ink is screen-printed on the first surface of the flexible substrate 1, and is dried and cured to form an implanted conductive area 211 of the first functional electrode 2. The non-implanted conductive area 212 and the implanted conductive area 211 form a series structure to jointly form the conductive area 21 of the first functional electrode 2; the preferred thickness of the carbon ink is 10-50 μm, the drying temperature is 90-120° C., and the drying time is 8-12 minutes.

[0032] S1.4, refer to Figure 3 , screen-print an insulating layer 4 on the first surface of the flexible substrate 1 and cure it, the insulating layer 4 covers the conductive area 21 of the first functional electrode 2, and exposes the working area 22; the material of the insulating layer 4 can be a UV light-cured insulating layer, which should be evenly coated and cured by UV light irradiation, the thickness of the insulating layer 4 is preferably 5-20μm, the wavelength of the UV light source is 365nm, the energy intensity is 100-150mJ / cm², and the illumination time is 10-30 seconds, to ensure insulation performance and mechanical protection effect. The insulating layer 4 should cover most of the conductive area 21 of the first functional electrode 2, and only be properly exposed in the working area 22 to avoid short circuit and signal interference.

[0033] After S1.4, a step of coating the anti-oxidation coating 5 on the surface of the contact region 213 of the first functional electrode 2 may be added.

[0034] The present application divides the conductive area 21 of the first functional electrode 2 into two parts, an implanted conductive area 211 implanted in the human body and a non-implanted conductive area 212 not implanted in the human body. The implanted conductive area 211 is a carbon circuit layer, and the non-implanted conductive area 212 is a silver circuit layer. The carbon circuit layer has good biocompatibility and the silver circuit layer has low resistance and high signal transmission efficiency. The circuit impedance of the functional electrode is effectively reduced, the signal transmission efficiency is improved, and the biocompatibility and long-term stability of the implanted area are ensured. The silver circuit layer and the carbon circuit layer form a series structure to ensure the passage of the conductive area 21. Whether it is a carbon circuit layer or a silver circuit layer, it can be made using silk screen technology, and combined with CCD automatic capture point technology, it can ensure high precision of position, shape and thickness, and effectively reduce the short circuit, circuit breakage or discontinuity problems caused by traditional processes.

[0035] In actual production, in order to improve production efficiency, a whole sheet of flexible substrate 1 material is provided, and then a whole sheet of implantable bioelectrodes is produced. After the test is completed and the electrode is shaped, it is cut into individual implantable bioelectrodes. This process has high processing efficiency and can realize mass production of implantable bioelectrodes, so the drawings provided in this embodiment are only simplified schematic diagrams.

[0036] In this embodiment, step S1.2 and step S1.3 can be exchanged. Since it is divided into two screen printings, it is preferably combined with CCD point capture technology to ensure high-precision positioning. Each screen printing must be dried to ensure that the ink is quickly solidified and has high adhesion. Therefore, after the screen printing and curing steps, quality control steps can be added, such as checking the shape accuracy and integrity of the coating through the AOI system to ensure that the silver circuit layer area is not exposed and the working area 22 is not covered, or adding manual sampling to ensure that the surface is smooth and pinhole-free after UV curing to ensure insulation effect and stability.

[0037] Embodiment 2: Reference Figures 5 to 9 , which is different from the implantable bioelectrode in the first embodiment in that it also includes a second functional electrode 3, the first functional electrode 2 and the second functional electrode 3 are stacked, and an insulating layer 4 is provided in between to achieve interlayer isolation, and the conductive area 31 of the second functional electrode 3 also includes an implanted conductive area 311 implanted in the human body and a non-implanted conductive area 312 not implanted in the human body, the implanted conductive area 311 is a carbon circuit layer, and the non-implanted conductive area 312 is a silver circuit layer, and the silver circuit layer and the carbon circuit layer form a series structure. The manufacturing method of the implantable bioelectrode described in this embodiment includes the following steps: S1.1, providing a flexible substrate 1.

[0038] S1.2, refer to Figure 5Silver ink is screen-printed on the first surface of the flexible substrate 1, and is dried and cured to form a non-implanted conductive area 21 of the first functional electrode 2 and a first detection point 23 of the first functional electrode 2. The first detection point 23 of the first functional electrode 2 is located at the outer end of the non-implanted conductive area 212 of the first functional electrode 2. The non-implanted conductive area 212 and the first detection point 23 of the first functional electrode 2 form a series structure. For specific parameters, refer to Example 1.

[0039] S1.3, refer to Figure 6 , carbon ink is screen-printed on the first surface of the flexible substrate 1, and is dried and cured to form an implanted conductive area 211 of the first functional electrode 2 and a second detection point 24 of the first functional electrode 2. The non-implanted conductive area 212 and the implanted conductive area 211 form a series structure to jointly form the conductive area 21 of the first functional electrode 2. The second detection point 24 of the first functional electrode 2 is located at the outer end of the implanted conductive area 211 of the first functional electrode 2. The implanted conductive area 211 and the second detection point 24 of the first functional electrode 2 also form a series structure. For specific parameters, please refer to Example 1.

[0040] S1.4, refer to Figure 7 An insulating layer 4 is screen-printed on the first surface of the flexible substrate 1 and cured. The insulating layer 4 covers the conductive area 21 of the first functional electrode 2 and exposes the working area 22. For specific parameters, refer to the first embodiment.

[0041] S1.5, refer to Figure 8 Silver ink is screen-printed on the first surface of the flexible substrate 1, and is dried and cured to form a non-implanted conductive area 312 of the second functional electrode 3 and a first detection point 33 of the second functional electrode 3. The first detection point 33 of the second functional electrode 3 is located at the outer end of the non-implanted conductive area 312 of the second functional electrode 3. The non-implanted conductive area 312 of the second functional electrode 3 and the first detection point 33 of the second functional electrode 3 form a series structure. For specific parameters, please refer to Example 1.

[0042] S1.6, refer to Fig. 9 , screen-print carbon ink on the first surface of the flexible substrate 1, and dry and solidify it to form the implanted conductive area 311 of the second functional electrode 3 and the second detection point 34 of the second functional electrode 3, the non-implanted conductive area 312 and the implanted conductive area 311 of the second functional electrode 3 form a series structure, and together form the conductive area 31 of the second functional electrode 3, the second detection point 34 of the second functional electrode 3 is located at the outer end of the implanted conductive area 311 of the second functional electrode 3, and the implanted conductive area 311 of the second functional electrode 3 and the second detection point 34 of the second functional electrode 3 form a series structure, and the specific parameters can refer to the first embodiment. Step S1.5 and step S1.6 can be exchanged.

[0043] After step S1.6, the second insulating layer 4 can be screen-printed on the first surface of the flexible substrate 1, and the anti-oxidation coating 5 can be coated on the contact area 313 of the first functional electrode 2 and the second functional electrode 3. After drying, the electrical performance of the first functional electrode 2 and the second functional electrode 3 can be tested through the first detection point 33 and the second detection point 34. After all the tests are completed, the first detection point 33 and the second detection point 34 are cut or removed, and the shape of the implantable bioelectrode and the shape of the functional electrode are shaped to ensure the consistency of size. For specific parameters, refer to Example 1.

[0044] In this embodiment, two functional electrodes are set on the surface of the flexible substrate 1 to improve the space utilization of the flexible substrate 1 and reduce the width of the laminated probe. This application designs a synchronous detection point solution, and uses automated detection equipment to detect resistance value, conductivity and short circuit conditions (detection data between two detection points of the same functional electrode, cross detection data between different functional electrodes). The circuit should be broken where it should be broken, and the resistance value of the connected place should be within the required range. This process realizes non-destructive testing of mass production, achieves the purpose of quality control, and improves production yield and consistency.

[0045] Embodiment three: Reference Fig.10 The difference between this embodiment and the first embodiment is that in step S1.3, a carbon material purity detection electrode 6 is simultaneously screen-printed on a blank area of ​​the first surface of the flexible substrate 1 to perform an electrochemical performance test.

[0046] Verifying the purity of carbon ink is of great importance. Carbon is mainly used in the carbon conductive lines of the counter electrode 9 and the working electrode 7 implanted in the human body. These carbon areas connect the sensitive material areas but do not participate in the electrochemical reaction. If there are other metal impurities in the carbon material, such as silver, it may affect the electrochemical performance of the electrode, resulting in the appearance of stray peaks in the cyclic voltammetry (CV) test curve, interfering with the normal electrochemical signal transmission. The present application can use the carbon material purity detection electrode 6 to detect the purity of the carbon material through automated detection equipment, and perform electrochemical performance tests (such as CV curve tests) to eliminate the interference of impurities in the carbon material. If the purity is insufficient, the carbon ink needs to be replaced in time to ensure that the carbon material is pure and the quality is stable, effectively eliminating the interference of stray peaks in the electrochemical test, and improving the purity and detection accuracy of the electrochemical signal. This design does not affect the arrangement and production of batch functional electrodes, and is convenient for timely quality verification and process monitoring during the production process.

[0047] Embodiment 4: Reference Figures 11 to 25 This embodiment discloses a method for making an implantable glucose monitoring probe. Fig.26 and Fig. 27The glucose monitoring probe comprises a flexible substrate 1, a working electrode 7, a reference electrode 8, a counter electrode 9 and a multi-layer insulating layer 4. The working electrode 7 and the reference electrode 8 are stacked from the inside to the outside on the front side of the flexible substrate 1, and the counter electrode 9 is arranged on the back side of the flexible substrate 1. The insulating layer 4 is arranged between the working electrode 7 and the reference electrode 8 to achieve interlayer isolation, and is arranged on the outer surfaces of the reference electrode 8 and the counter electrode 9 to play an insulating protection role. The working electrode 7, the reference electrode 8 and the counter electrode 9 all include conductive areas 71, 81, 91 and working areas 72, 82, 92 The conductive areas 71, 81, 91 are electrically connected to the working areas 72, 82, 92. The conductive areas 71, 81, 91 include implanted conductive areas 711, 811, 911 implanted in the human body and non-implanted conductive areas 712, 812, 912 not implanted in the human body. The working areas 72, 82 of the working electrode 7 and the reference electrode 8 are both provided with sensitive materials. The implanted conductive area 911 of the counter electrode 9 is the working area. Since the working principles of the working electrode 7, the reference electrode 8 and the counter electrode 9 and various molding methods are introduced in the prior art, they will not be described in detail here. The manufacturing method comprises the following steps: S2.1, providing a full-page flexible substrate 1 material; S2.2, reference Fig.11 , screen printing the non-implanted conductive area 912 of the counter electrode 9 on the back side of the flexible substrate 1 material, the material is silver ink, and then drying and curing; S2.3, reference Fig.12 , the implanted conductive area 911 of the counter electrode 9 is screen-printed on the back of the flexible substrate 1 material, the material is carbon ink, and then dried and cured, the non-implanted conductive area 912 of the counter electrode 9 and the implanted conductive area 911 form a series structure, and together form the conductive area 91 of the counter electrode 9; S2.4, reference Fig.13 , screen-printing an insulating layer 4 on the back of the flexible substrate 1 material, and then curing it, wherein the insulating layer 4 covers the non-implanted conductive area 912 of the electrode 9, exposing the working area; S2.5, reference Fig.14 , turning over the flexible substrate 1 material, screen printing the non-implanted conductive area 712 of the working electrode 7 on the front side of the flexible substrate 1 material, the material being silver ink, and then drying and curing; S2.6, reference Fig.15 , screen printing the implanted conductive area 711 of the working electrode 7 on the front side of the flexible substrate 1 material, the material is carbon ink, and then drying and curing; S2.7, reference Fig.16, a first insulating layer 4 is screen-printed on the front side of the flexible substrate 1 material, and then cured, the first insulating layer 4 covers the conductive area 71 of the working electrode 7 and a partial area of ​​the flexible substrate 1, so that the working electrode 7 and the reference electrode 8 are isolated from each other; the first insulating layer 4 should cover most of the conductive area 71 of the working electrode 7 and a partial area of ​​the flexible substrate 1, so that the working electrode 7 and the reference electrode 8 are isolated from each other.

[0048] S2.8, reference Fig.17 , screen printing the non-implanted conductive area 812 of the reference electrode 8 on the front side of the flexible substrate 1 material, the material is silver ink, and then drying and curing; S2.9, reference Fig.18 , screen printing the implanted conductive area 811 of the reference electrode 8 on the front side of the flexible substrate 1 material, the material is carbon ink, and then drying and curing; S2.10, cf. Fig.19 The second insulating layer 4 is screen-printed on the front side of the flexible substrate 1 material and then cured. The second insulating layer 4 covers most of the conductive area 81 of the reference electrode 8, exposing the working area 82 of the reference electrode 8; ensuring the insulation performance and mechanical protection effect to avoid short circuit and signal interference.

[0049] S2.11, cf. Fig. 20 , screen print the sensitive material on the working area 82 of the reference electrode 8, then dry and solidify it, and the sensitive material is electrically connected to the conductive area 81 of the reference electrode 8; the sensitive material can be silver chloride, which should be printed evenly and without defects, to ensure that the sensitive material is well connected to the conductive area 81 of the reference electrode 8. The thickness of the silver chloride is preferably 10-30 μm, and then dry and solidify it, the temperature is preferably 120-150°C, and the drying time is 5-10 minutes.

[0050] S2.12, cf. Fig.21 , screen print the sensitive material on the working area 72 of the working electrode 7, then dry and solidify it, and the sensitive material is electrically connected to the conductive area 71 of the working electrode 7; the sensitive material can be PEDOT, carbon nanotubes, platinum carbon or gold materials, and should be printed evenly without pinholes, bubbles, stratification or missing, to ensure that the sensitive material is well connected to the conductive area 71 of the working electrode 7 to form a functional layer, giving high-performance catalytic and electrochemical detection capabilities. The thickness of the sensitive material is preferably 5-20μm, and then it is dried and solidified, the temperature is preferably 90-120℃, and the drying time is 5-10 minutes.

[0051] S2.13, cf. Fig. 22, an array of micropores is processed in the working area 72 of the working electrode 7 to provide a precise area for the attachment of the enzyme layer 10; the surface of the sensitive material of the working electrode 7 is preferably processed by ultraviolet picosecond laser to form a micropore array 721 for loading the enzyme layer 10, the depth of the micropore array 721 is less than the thickness of the sensitive material, the micropores are evenly distributed and will not burn through the sensitive material of the working electrode 7, and will not damage the flexible substrate 1, and provide a precise area for the attachment of the enzyme layer 10, the diameter of the array micropores is 20-100μm; the depth of the micropores is 0.5-5μm, which can increase the specific surface area, improve the enzyme adhesion and catalytic efficiency. The microporous structure can significantly increase the specific surface area of ​​the working electrode 7, provide a precise area for enzyme attachment, improve adhesion, catalytic efficiency and uniformity of the reaction area, and effectively improve the reaction sensitivity of the working electrode 7.

[0052] S2.14, cf. Fig.23 , make enzyme layer 10 (enzyme fixation), use enzyme spotting machine to accurately spot enzyme material in array micropores, preferably use CCD grabbing technology combined with high-precision enzyme spotting machine to accurately spot enzyme material (such as glucose oxidase or peroxidase) in array micropores, to ensure uniform distribution and stable attachment of enzyme layer 10; the enzyme layer 10 is made of a mixture of nanowires and conductive media, the nanowires can be conductive nanowires, carbon nanotubes, etc., which can significantly reduce the catalytic potential of the enzyme, improve the reaction sensitivity of the working electrode 7, and enhance the stability of enzyme attachment, effectively reduce the detachment of the enzyme layer 10, and extend the service life of the bioelectrode. The spot coating amount of each micropore is preferably 0.1-0.5μL, the drying temperature is 40℃, and the time is 10 minutes.

[0053] S2.15, a biocompatible film is coated on the working area 72 of the working electrode 7 to cover the enzyme layer 10, but the micropores cannot be completely closed. This is a prior art and will not be described in detail here. The equipment can use a sprayer and a variety of spraying methods, such as air spraying, atomization spraying or electrostatic spraying technology. The biocompatible film can use PVP (polyvinyl pyrrolidone), PU (polyurethane), NAFION and other biocompatible films. The film layer has excellent biocompatibility, flexibility and chemical resistance, provides good biocompatibility and mechanical protection, effectively reduces immune rejection reactions after implantation, protects the enzyme layer 10 of the working electrode 7, and prevents interferences in body fluids (such as uric acid, ascorbic acid) from affecting the detection signal. It can effectively reduce external environmental interference and is very suitable for medical applications such as biosensors to improve the stability and biocompatibility of the working electrode 7 in the biological environment and extend the service life of the probe. The preferred thickness of the biocompatible film is 10-50 μm, and the thickness can be adjusted according to actual application requirements to ensure that the film layer is uniform and does not affect the performance of the working electrode 7. It is necessary to ensure that there are no defects during the film covering process to avoid bubbles, wrinkles or incomplete film layers.

[0054] S2.16, cf. Fig.24 , the tails of the working electrode 7, the reference electrode 8 and the counter electrode 9 are contact areas 713, 83, 92, and a layer of anti-oxidation coating 5 is coated on the contact areas 713, 83, 92; the material of the anti-oxidation coating 5 is usually a polymer coating with high chemical stability and anti-oxidation properties, which can enhance the anti-oxidation ability and durability of the functional electrode during long-term use or plug-in test links. The material of the anti-oxidation coating 5 is usually a polymer coating with high chemical stability and anti-oxidation properties, such as epoxy resin, polyvinyl difluoride (PVDF) or other polymer materials. The coating thickness is generally controlled at 5-20μm to ensure that the coating is uniform and does not affect the conductive properties of the functional electrode. After coating, the anti-oxidation coating 5 needs to be cured to enhance its durability and stability; the curing temperature is preferably 80-120℃, and the curing time is 5-15 minutes to ensure that the anti-oxidation coating 5 is completely cured to achieve the best anti-oxidation effect, which is adjusted according to the characteristics of the coating material.

[0055] S2.17, cf. Fig.25 , using laser engraving process, the shape of the glucose monitoring probe, as well as the working electrode 7, reference electrode 8 and counter electrode 9 are precisely engraved; preferably, the ultraviolet picosecond laser engraving process is used to precisely engrave the functional electrode of the probe to ensure the consistency of the size and structure of the functional electrode. This process meets the strict requirements of implantable electrodes for miniaturization and high-precision shape processing and is suitable for large-scale batch production. The laser power is preferably 1-10W (set according to the substrate material), the engraving accuracy is ±10μm; the engraving speed is 100-300 mm / s.

[0056] S2.18, dividing the entire plate of glucose monitoring probes into monomeric glucose monitoring probes.

[0057] In this embodiment, in step S2.1, an array of conductive through holes 11 is made on the entire flexible substrate 1 material. The number of each group of conductive through holes 11 can be multiple to increase the conductive cross-sectional area. The conductive through holes 11 can be processed by microsecond laser engraving technology. The purpose of setting the conductive through holes 11 is to enable the back and front parts of the electrode 9 to be electrically connected. The preferred diameter of the conductive through holes 11 is 50-100 μm, and the number is preferably 3. In step S2.2, silver ink enters the conductive through holes 11; in step S2.5, the contact area 92 of the electrode 9 is also made simultaneously. The contact area 92 of the electrode 9 is electrically connected to the electrode 9 through the conductive through holes 11, and the contact area 92 of the electrode 9 is transferred to the front of the flexible substrate 1 material.

[0058] The conductive through hole 11 is used to contain silver paste, so that the counter electrode 9 on the back side of the flexible substrate 1 and the contact area 92 of the counter electrode 9 on the front side are electrically connected. The silver ink in the contact area 92 of the counter electrode 9 will penetrate into the conductive through hole 11, thereby realizing the conductive connection between the counter electrode 9 on the back side and the contact area 92 on the front side, increasing the integration of functional electrodes and meeting the requirements of high-density functional electrodes.

[0059] In the present application, the flexible substrate 1 is made of polyimide or polyethylene terephthalate material; the sensitive material on the working electrode 7 is PEDOT, carbon nanotubes, platinum carbon or gold material; the sensitive material on the reference electrode 8 is silver chloride; the insulating layer 4 is an insulating UV light-curing glue. By superimposing multiple layers of UV light-curing insulating layers 4, effective isolation between the conductive layers is ensured, circuit short circuit and signal interference are prevented, and the electrical stability and overall reliability of the functional electrode structure are improved.

[0060] In this embodiment, in step S2.1, a conductive through hole 11 is made on the entire flexible substrate 1 material using a microsecond laser engraving device, and the diameter of the conductive through hole 11 is 50-100 μm; in step S2.13, an array of micropores is processed in the working area 72 of the working electrode 7 using an ultraviolet picosecond laser processing device, and the diameter of the array of micropores is 20-100 μm and the depth is 0.5-5 μm; in step S2.17, laser engraving is performed using an ultraviolet picosecond laser processing device.

[0061] After each layer of conductive material and insulating layer is screen-printed in this application, it is subjected to high-temperature curing treatment, which can significantly enhance the adhesion and conductivity of the ink, avoid interlayer shedding problems, and enhance the overall structural stability and reliability.

[0062] In this embodiment, in step S2.3, the first detection point 93 of the counter electrode 9 is synchronously produced, in step S2.5, the first detection point 73 of the working electrode 7 and the second detection point 94 of the counter electrode 9 are synchronously produced, in step S2.6, the second detection point 74 of the working electrode 7 is synchronously produced, in step S2.8, the first detection point 84 of the reference electrode 8 is synchronously produced, and in step S2.9, the second detection point 85 of the reference electrode 8 is synchronously produced; in step S2.17, the first detection points 93, 73, 84 and the second detection points 94, 74, 85 of the counter electrode 9, the working electrode 7 and the reference electrode 8 are cut off or cleared.

[0063] In this embodiment, in steps S2.3, S2.6 and S2.9, the carbon material purity detection electrode 6 can be simultaneously manufactured in the blank space of the entire flexible substrate 1 material.

[0064] In this embodiment, functional electrodes with different functions are arranged on both the front and back sides of the flexible substrate 1. The functional electrodes on the same surface are stacked to improve the space utilization of the flexible substrate 1 and reduce the width of the stacked probes.

[0065] The manufacturing method of the implantable glucose monitoring probe of the present application innovatively introduces a silver-carbon series circuit manufacturing process, an ultraviolet picosecond laser micropore processing process, a precise enzyme point process, a biocompatible film coating process, and an ultraviolet picosecond laser engraving molding process, which comprehensively improves the manufacturing accuracy, enzyme fixation uniformity, electrochemical performance, biocompatibility, and production efficiency of the implantable bioelectrode. These key technical points not only solve many technical bottlenecks in traditional processes, but also ensure the high performance and high stability of the functional electrodes through multi-level protection measures, thereby realizing the wide application and commercial production of bioelectrodes in the fields of CGM and plug-in rapid detection. More specifically, by optimizing the conductive material combination of the functional electrode, the problems of high impedance and low signal transmission efficiency in the traditional technology are effectively solved. The problems of uneven enzyme layer 10 and low enzyme catalytic efficiency are effectively solved through precise array micropore processing and enzyme layer 10 fixation technology. By using high-purity carbon ink, the problem of electrochemical impurities is solved. By using high-precision laser processing, the problems of low processing accuracy and insufficient quality control of the functional electrodes and probes are solved, ensuring that the electrodes can be mass-produced with high performance and high stability, and are suitable for medical health monitoring, clinical diagnosis, environmental monitoring and other electrochemical detection applications requiring high sensitivity and high stability.

[0066] In order to further enhance the applicability and flexibility of the present invention, the following material alternatives are provided. These alternatives are mainly aimed at replacing key materials, aiming to adapt to different application requirements and production conditions. Although they may not be better in all cases, they can be selected and adjusted according to specific needs. In addition, the bioelectrode of the present invention is not only suitable for the field of continuous glucose monitoring (CGM), but can also be widely used in the field of plug-in rapid detection, such as body fluid analysis, environmental monitoring and clinical diagnosis.

[0067] 1. Alternative options for conductive materials: Pure carbon materials replace carbon-silver mixed materials. In some application scenarios, pure carbon (Pure Carbon) can be used to replace carbon and silver mixed materials. Pure carbon materials have good biocompatibility and conductivity, and are suitable for electrochemical detection applications that need to reduce interference from metal impurities. Although the conductivity of pure carbon materials may be slightly lower than that of carbon-silver mixed materials, they have advantages in reducing electrochemical impurity peaks.

[0068] Alternative silver materials: Copper has excellent electrical conductivity and low cost, and can be used as an alternative to silver for conductive lines in non-implanted areas. However, copper is easily oxidized, so appropriate protective measures must be taken during use to ensure its stability. Gold has excellent electrical conductivity and chemical stability, and can replace silver for conductive lines with high stability requirements. Although gold is more expensive, its corrosion resistance in long-term use gives it a unique advantage in some high-end applications.

[0069] 2. Alternative options for biocompatible membrane materials: Materials that replace PVP, PU, ​​and Nafion, Polyvinyl Alcohol (PVA): PVA has good biocompatibility and controllable film thickness, and is suitable as a biocompatible film material to provide a protective layer and reduce immune response. Polymethyl methacrylate (PMMA), the PMMA film layer has high transparency and good mechanical strength, and can be used to protect the electrode structure while providing the necessary biocompatibility. Biodegradable polymers (such as polylactic acid-glycolic acid copolymer, PLGA): Suitable for sensor designs that need to be gradually degraded in the body, providing short-term protection and naturally degrading after the sensor fails, reducing long-term effects on the human body.

[0070] 3. Alternative options for sensitive materials: Graphene is a material that replaces PEDOT, platinum carbon, carbon nanotubes, and polyaniline. Graphene has extremely high conductivity and flexibility, and is suitable for sensitive materials of working electrodes. Its two-dimensional structure provides a larger specific surface area, which helps to fix enzymes and improve the efficiency of electrochemical reactions. Conductive polymers (such as polypyrrole) have good conductivity and adjustable chemical properties, and are suitable as alternative sensitive materials to meet different electrochemical detection needs.

[0071] 4. Alternative options for insulation materials: Materials that replace UV light-curing polymers: Epoxy resin: Epoxy resin has excellent mechanical strength and chemical stability and can be used as an alternative material for the insulation layer to provide effective electrical isolation and mechanical protection. Silicone rubber: Silicone rubber has good elasticity and chemical resistance and is suitable as a flexible insulation layer material to provide additional flexibility and durability.

[0072] 5. Alternative options for antioxidant coating materials: Silicon Nitride (Si3N4) is a material that replaces epoxy resin and polyvinyl difluoride (PVDF). Silicon nitride has excellent oxidation resistance and chemical stability, and is suitable as an antioxidant coating material to provide an efficient protective layer. Aluminum Oxide (Al2O3): Aluminum oxide has good mechanical strength and oxidation resistance, and can be used to replace polyvinyl difluoride (PVDF) to provide strong antioxidant protection.

[0073] 6. Alternative options for flexible substrate materials: Materials that replace polyimide (PI) and polyethylene terephthalate (PET), PolyetherEther Ketone (PEEK): PEEK has excellent mechanical properties and chemical stability, and is suitable for applications that require higher strength and temperature resistance. Polyurethane (PU): Polyurethane provides higher flexibility and elasticity, and is suitable for implantable sensor designs that require greater flexibility and bendability. Stretchable polymers (such as polydimethylsiloxane, Polydimethylsiloxane, PDMS): Suitable for sensors that require highly soft and stretchable properties, providing better fit and comfort.

[0074] VII. Alternatives for enzyme immobilization auxiliary materials Materials that replace cross-linkers, cross-linker-free fixation method: Enzymes are fixed by physical adsorption or charge interaction, without the need for chemical cross-linkers, simplifying process steps and reducing the risk of chemical residues. Biocompatible adhesives: Use natural or synthetic biocompatible adhesives, such as gelatin or chitosan, to assist enzyme fixation and enhance the stability and adhesion of the enzyme layer.

[0075] 8. Expansion of the application field of stacked probes: Plug-in rapid detection field: In addition to continuous glucose monitoring (CGM), the laminated probe of the present invention is also suitable for plug-in rapid detection fields, such as body fluid analysis (blood, urine, etc.), environmental monitoring (air, water quality, etc.) and clinical diagnosis (biomarker detection, etc.). By flexibly adjusting the electrode material and membrane layer design, different detection environments and needs can be met, and the development of multifunctional sensors can be realized.

[0076] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for manufacturing an implantable bioelectrode, wherein the implantable bioelectrode comprises a flexible substrate and a first functional electrode, wherein the first functional electrode comprises a conductive area and a working area, wherein the conductive area is further divided into a non-implanted conductive area and an implanted conductive area, wherein: The following steps are involved: S1.1, providing a flexible substrate; S1.2, screen printing silver ink on the first surface of the flexible substrate, and drying and curing the ink to form a non-implanted conductive area of ​​the first functional electrode; S1.3, screen printing carbon ink on the first surface of the flexible substrate, and drying and curing the ink to form an implanted conductive area of ​​the first functional electrode, wherein the non-implanted conductive area and the implanted conductive area form a series structure to form a conductive area of ​​the first functional electrode; S1.4, screen-printing an insulating layer on the first surface of the flexible substrate and curing the layer, wherein the insulating layer covers the conductive area of ​​the first functional electrode and exposes the working area.

2. The method for making an implantable bioelectrode according to claim 1, characterized in that: The implantable bioelectrode further includes a second functional electrode, and after step S1.4, further includes step S1.5, screen printing silver ink on the first surface of the flexible substrate, and drying and curing the ink to form a non-implanted conductive area of ​​the second functional electrode; S1.6, screen printing carbon ink on the first surface of the flexible substrate, and drying and curing it to form an implanted conductive area of ​​the second functional electrode. The non-implanted conductive area and the implanted conductive area form a series structure to jointly form a conductive area of ​​the second functional electrode.

3. The method for making an implantable bioelectrode according to claim 1, characterized in that: In step S1.2, a first detection point of the first functional electrode is also synchronously screen-printed, and the first detection point of the first functional electrode is located at the outer end of the non-implanted conductive area of ​​the first functional electrode; in step S1.3, a second detection point of the first functional electrode is also synchronously screen-printed, and the second detection point of the first functional electrode is located at the outer end of the implanted conductive area of ​​the first functional electrode; After the test is completed, cut or remove the first detection point and the second detection point.

4. The method for making an implantable bioelectrode according to claim 1, characterized in that: In step S1.3, a carbon material purity detection electrode is simultaneously screen-printed on a blank area of ​​the first surface of the flexible substrate to perform an electrochemical performance test.

5. The method for making an implantable bioelectrode according to claim 1, characterized in that: In step S1.2, the thickness of the silver ink is 10-50 μm, the drying temperature is 120-150° C., and the time is 5-10 minutes; in step S1.3, the thickness of the carbon ink is 10-50 μm, the drying temperature is 90-120° C., and the time is 8-12 minutes.

6. The method for manufacturing an implantable bioelectrode according to claim 1, characterized in that: The material of the insulating layer is a UV light-curing insulating layer, which is cured by UV light irradiation. The thickness of the insulating layer is 5-20 μm, the wavelength of the UV light source is 365 nm, the energy intensity is 100-150 mJ / cm², and the irradiation time is 10-30 seconds.

7. A method for making an implantable glucose monitoring probe, the glucose monitoring probe comprising a flexible substrate, a working electrode, a reference electrode, a counter electrode and a multi-layer insulating layer, the working electrode and the reference electrode are stacked from the inside to the outside on the front side of the flexible substrate, the counter electrode is arranged on the back side of the flexible substrate, the insulating layer is arranged between the working electrode and the reference electrode to achieve interlayer isolation, and is arranged on the outer surface of the reference electrode and the counter electrode to play an insulating protection role, the working electrode, the reference electrode and the counter electrode all include a conductive area and a working area, the conductive area and the working area are electrically connected, the conductive area includes an implanted conductive area implanted in the human body and a non-implanted conductive area not implanted in the human body, the working areas of the working electrode and the reference electrode are provided with sensitive materials, the implanted conductive area of ​​the counter electrode is the working area, characterized in that The following steps are involved: S2.1, provide a full sheet of flexible substrate material; S2.2, screen printing a non-implanted conductive area of ​​the counter electrode on the back side of the flexible substrate material, the material being silver ink, and then drying and curing; S2.3, screen printing the implanted conductive area of ​​the counter electrode on the back side of the flexible substrate material, the material is carbon ink, and then drying and curing, the non-implanted conductive area and the implanted conductive area of ​​the counter electrode form a series structure, and together form a conductive area of ​​the counter electrode; S2.4, screen printing an insulating layer on the back side of the flexible substrate material, and then curing it, wherein the insulating layer covers the non-implanted conductive area of ​​the counter electrode, exposing the working area; S2.5, turning over the flexible substrate material, screen-printing the non-implanted conductive area of ​​the working electrode on the front side of the flexible substrate material, the material being silver ink, and then drying and curing; S2.6, screen printing the implanted conductive area of ​​the working electrode on the front side of the flexible substrate material, the material is carbon ink, and then drying and curing; S2.7, screen printing a first insulating layer on the front side of the flexible substrate material, and then curing the first insulating layer, wherein the first insulating layer covers the conductive area of ​​the working electrode and a part of the flexible substrate, so that the working electrode and the reference electrode are isolated from each other; S2.8, screen printing a non-implanted conductive area of ​​a reference electrode on the front side of the flexible substrate material, the material being silver ink, and then drying and curing; S2.9, screen printing the implanted conductive area of ​​the reference electrode on the front side of the flexible substrate material, the material being carbon ink, and then drying and curing; S2.10, screen printing a second insulating layer on the front side of the flexible substrate material, and then curing the second insulating layer, wherein the second insulating layer covers most of the conductive area of ​​the reference electrode, exposing the working area of ​​the reference electrode; S2.11, screen printing the sensitive material on the working area of ​​the reference electrode, and then drying and curing it, so that the sensitive material is electrically connected to the conductive area of ​​the reference electrode; S2.12, screen printing a sensitive material on the working area of ​​the working electrode, and then drying and curing the sensitive material, so that the sensitive material is electrically connected to the conductive area of ​​the working electrode; S2.13, processing array micropores in the working area of ​​the working electrode to provide a precise area for the attachment of the enzyme layer; S2.14, making an enzyme layer, using an enzyme spotting machine to precisely spot the enzyme material in the microwells of the array; S2.15, coating a biocompatible film on the working area of ​​the working electrode to cover the enzyme layer; S2.16, the tails of the working electrode, reference electrode and counter electrode are contact areas, and an anti-oxidation coating is applied to the contact areas; S2.17, using a laser engraving process to accurately engrave the shape of the glucose monitoring probe, as well as the shapes of the working electrode, the reference electrode, and the counter electrode; S2.18, dividing the entire plate of glucose monitoring probes into monomeric glucose monitoring probes.

8. The method for making an implantable glucose monitoring probe according to claim 7, characterized in that: In step S2.1, an array of conductive through holes is produced on a whole sheet of flexible substrate material; in step S2.2, silver ink is introduced into the conductive through holes; in step S2.5, a contact area for the counter electrode is also produced simultaneously, and the contact area for the counter electrode is electrically connected to the counter electrode through the conductive through holes, thereby transferring the contact area for the counter electrode to the front side of the flexible substrate material.

9. The method for making an implantable glucose monitoring probe according to claim 8, characterized in that: In step S2.1, conductive vias are made on the entire flexible substrate material using a microsecond laser engraving device, and the diameter of the conductive vias is 50-100μm; in step S2.13, array micropores are processed in the working area of ​​the working electrode using an ultraviolet picosecond laser processing device, and the diameter of the array micropores is 20-100μm and the depth is 0.5-5μm; in step S2.17, laser engraving is performed using an ultraviolet picosecond laser processing device.

10. The method for making an implantable glucose monitoring probe according to claim 8, characterized in that: In steps S2.3, S2.6 and S2.9, carbon material purity detection electrodes are simultaneously produced in blank spaces of the entire flexible substrate material; in step S2.3, the first detection point of the counter electrode is simultaneously produced, in step S2.5, the first detection point of the working electrode and the second detection point of the counter electrode are simultaneously produced, in step S2.6, the second detection point of the working electrode is simultaneously produced, in step S2.8, the first detection point of the reference electrode is simultaneously produced, and in step S2.9, the second detection point of the reference electrode is simultaneously produced; in step S2.17, the first detection point and the second detection point of the counter electrode, the working electrode and the reference electrode are cut off or cleared.

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