Redox polymer having hyperbranched structure, glucose sensing material, preparation method therefor, and use thereof

Abstract

The present invention relates to the technical field of glucose detection. Disclosed are a redox polymer having a hyperbranched structure, a glucose sensing material, a preparation method therefor, and a use thereof. The preparation method for the polymer comprises the following steps: modifying a hydroxyl-terminated hyperbranched polymer by means of a cyclic dianhydride compound to obtain a carboxyl-terminated hyperbranched polymer; and coupling the carboxyl-terminated hyperbranched polymer with a redox ligand containing an amino functional group to obtain the polymer. The polymer has a three-dimensional spherical structure and the characteristic of the molecular chain being not prone to entanglement. It can be ensured that each redox ligand has a sufficient free movement capability and can be fully utilized, and the redox ligands can freely move and collide with each other and transmit electrons, thereby increasing the electron transfer rate, thus overcoming the oxygen effect problem in existing wired enzyme technology. In addition, the molecular chain of the redox polymer having a hyperbranched structure is not easily entangled, so that the viscosity of the redox polymer having a hyperbranched structure is lower than that of a linear polymer with the same molecular weight, and the redox polymer having a hyperbranched structure has excellent fluidity and film-forming property.

Description

Hyperbranched redox polymer, glucose sensing material, and preparation method and application thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 19, 2023, with application number "202311756870.7" and invention name "Hyperbranched structure redox polymers, glucose sensing materials and their preparation methods and applications", the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to a hyperbranched redox polymer, a glucose sensing material, and a preparation method and application thereof, and belongs to the technical field of glucose detection. Background Art

[0003] With the development of society, the risk of diabetes is increasing annually. According to the International Diabetes Federation (IDF), the number of adults with diabetes worldwide is expected to increase by 48% by 2045, from 425 million in 2017 to 625 million. Diabetes has become a global public health issue that urgently needs to be addressed and resolved. Currently, the clinical treatment for diabetes involves measuring blood glucose levels through finger pricks several times a day, followed by insulin injections to normalize blood glucose levels. However, this treatment approach struggles to accurately control postprandial hyperglycemia and nocturnal hypoglycemia, as patients rely on real-time blood glucose data to adjust their insulin dosage. These limitations, coupled with the pain associated with repeated finger pricks, make this approach unsuitable for both patients and physicians. Over the past few decades, more sophisticated implantable blood glucose tracking devices, such as continuous glucose monitors (CGMs), have been developed. CGMs continuously capture blood glucose fluctuations, enabling comprehensive tracking of blood glucose trends over time.

[0004] The working principle of the second-generation CGM is to use an artificially chemically synthesized mediator to achieve electron transfer between glucose oxidase and the electrode, known as wired enzyme technology. The electron mediator is grafted onto the side chain of a water-soluble linear polymer via a long flexible chain. Specific technical details are provided in US patent application publication number US6605200 B1. The redox center of glucose oxidase, flavin adenine dinucleotide (FAD), is surrounded by a thick insulating layer. The mediator with a long flexible chain can effectively contact the FAD, transferring electrons. Through rapid reduction and oxidation, charge carriers such as electrons or holes are formed, which conduct current through self-exchange. The reduced mediator collides with the oxidized mediator, transferring electrons or holes. Although in theory, electrons or holes can also propagate by hopping between fixed mediators, the trap-trap hopping phenomenon observed in solid-state physics is rarely observed in redox hydrogels. Mediators with long flexible chains transfer electrons faster than those with short chains. This is because the long flexible chains increase the displacement amplitude of the tethered mediator, significantly increasing the frequency of contact collisions. Furthermore, patent application CN200980139400.8 synthesizes electron mediators with different redox potentials by adjusting the ligands of the synthetic mediators. These electron mediators generally have redox potentials below 0.3V, improving the anti-interference ability of the CGMS. Although the synthetic mediators facilitate electron transfer between glucose oxidase and the electrode, oxygen still transfers electrons with glucose oxidase. Therefore, there is a competitive relationship between oxygen and the synthetic mediators. Electron mediators grafted onto the side chains of linear polymers often transfer electrons and holes through collisions between adjacent electron mediators. However, linear polymers often suffer from chain entanglement, resulting in localized high or low concentrations of electron mediators, leading to inefficient electron mediator utilization. Furthermore, the efficiency of electron transfer is limited by the fact that electron mediators can only transfer electrons and holes between adjacent electron mediators. Therefore, to reduce the competitive interference of oxygen (the oxygen effect), patents such as CN113521399 A and US6932894 B2 have developed a biocompatible outer membrane to reduce oxygen penetration into the sensing layer while also controlling the flux of glucose into the sensing layer. While this membrane reduces oxygen interference, oxygen, as a small molecule dissolved in body fluids, still diffuses into the sensing layer through slightly swollen pores along with water molecules, competing with electron mediators to transfer electrons from glucose oxidase.

[0005] Furthermore, during electrode preparation, a dilute solution of a redox polymer (artificial electron mediator), glucose oxidase solution, and a crosslinker is applied to the working electrode surface via spin coating, spot coating, dip coating, or spraying to form an enzyme film layer approximately 5 μm thick. This processing method requires a relatively low viscosity of the mixed solution. Conventional redox polymers are high-molecular-weight linear polymers, and the viscosity of the polymer solution increases dramatically with molecular weight, limiting their application.

[0006] Summary of the Invention

[0007] In order to solve the above problems, a hyperbranched redox polymer, a glucose sensing material, and a preparation method and application thereof are provided. The prepared hyperbranched redox polymer has a three-dimensional spherical structure, and the molecular chain is not easily entangled, which can ensure that each redox ligand has sufficient free movement ability and can be fully utilized. They can freely move and collide with each other to transfer electrons, thereby increasing the electron transfer rate and overcoming the oxygen effect problem in the current wired enzyme technology. In addition, the molecular chain of the hyperbranched redox polymer with a three-dimensional spherical structure is not easily entangled, so that under the same molecular weight, its viscosity is lower than that of the linear polymer, and it has excellent flow properties and film-forming properties, thereby improving the consistency of sensitivity between prepared electrode batches.

[0008] According to one aspect of the present application, a method for preparing a hyperbranched structure redox polymer is provided, comprising the following steps: modifying a hydroxyl-terminated hyperbranched polymer using a cyclic dianhydride compound to obtain a carboxyl-terminated hyperbranched polymer; and coupling the carboxyl-terminated hyperbranched polymer with a redox ligand containing an amino functional group to obtain the hyperbranched structure redox polymer.

[0009] Optionally, the weight ratio of the carboxyl-terminated hyperbranched polymer to the redox ligand containing an amino functional group is 10:1-1:1, preferably 3:1.

[0010] Optionally, the redox ligand containing an amino functional group is a complex of a bidentate nitrogen heterocyclic compound and a metal ion;

[0011] Preferably, the bidentate nitrogen heterocyclic compound is N,N′-dimethyl-2,2′-biimidazole; and the metal ion is osmium or ruthenium.

[0012] Optionally, the cyclic dianhydride compound includes at least one of maleic anhydride, glutaric anhydride, succinic anhydride, itaconic anhydride and adipic anhydride; preferably, the cyclic dianhydride compound is glutaric anhydride; and / or

[0013] The hydroxyl-terminated hyperbranched polymer is a hydroxyl-terminated hyperbranched polyester and / or a hydroxyl-terminated hyperbranched polyether, preferably a hydroxyl-terminated hyperbranched polyester.

[0014] According to another aspect of the present application, a hyperbranched redox polymer is provided. The hyperbranched redox polymer is prepared by the above-mentioned preparation method.

[0015] According to another aspect of the present application, a method for preparing a glucose sensing material is provided. The glucose sensing material is obtained by covalent cross-linking reaction of an aqueous solution of the hyperbranched redox polymer, a glucose oxidase solution, and a cross-linking agent solution.

[0016] Optionally, the reaction temperature of the covalent cross-linking reaction is 20 to 50° C., and the reaction time is 1 to 60 hours;

[0017] Preferably, the reaction temperature of the covalent cross-linking reaction is 45° C., and the reaction time is 48 h.

[0018] Optionally, the concentration of the aqueous solution of the hyperbranched redox polymer is 1-20 mg / mL, the concentration of the glucose oxidase solution is 1-10 mg / mL, and the concentration of the crosslinker solution is 1-10 mg / mL; the mass ratio of the hyperbranched redox polymer, glucose oxidase, and crosslinker is 1:(0.1-5):(0.01-0.5).

[0019] Specifically, the cross-linking agent includes trimethylolpropane tris[3-(aziridin-1-yl)propionate.

[0020] According to another aspect of the present application, a glucose sensing material is provided. The glucose sensing material is prepared using the above-mentioned preparation method.

[0021] According to another aspect of the present application, there is also provided the use of the above-mentioned glucose sensing material in an intelligent glucose monitoring instrument and a diabetes management instrument.

[0022] The beneficial effects of this application include but are not limited to:

[0023] 1. According to the hyperbranched redox polymer of the present application, the hyperbranched redox polymer has a three-dimensional spherical structure, and the characteristic that the molecular chain is not easily entangled can ensure that each redox ligand has sufficient free movement ability, can be fully utilized, and can freely move and collide with each other to transfer electrons, thereby increasing the electron transfer rate and overcoming the oxygen effect problem in the current wired enzyme technology.

[0024] 2. According to the hyperbranched redox polymer of the present application, the hyperbranched redox polymer has a large number of short side chains and a three-dimensional spherical structure. The molecular chains are not easy to entangle and the interaction force between molecules is small, so the viscosity is low; while linear polymers are easy to entangle and knot, and the interaction force between molecules is large. Therefore, under the same molecular weight, the viscosity of the hyperbranched redox polymer is lower than that of the linear polymer, and it has excellent flow properties and film-forming properties, which is beneficial to ensure the consistency of the size and thickness of the electrode enzyme membrane layer in mass production, and thus ensure the sensitivity consistency of the mass-produced electrodes.

[0025] 3. According to the hyperbranched structure redox polymer of the present application, by limiting the weight ratio of the terminal carboxyl hyperbranched polymer to the redox ligand containing an amino functional group, the carboxyl content in the terminal carboxyl hyperbranched polymer is much greater than the amount of amino groups in the redox ligand, so as to ensure that each redox ligand can fully react on the polymer chain.

[0026] 4. The glucose sensing material provided in the present application can be applied to intelligent glucose monitoring instruments and diabetes management instruments to specifically detect glucose. Its stable current signal has a high linear correlation coefficient with the glucose concentration, and can eliminate the influence of interfering substances such as acetaminophen and ascorbic acid on glucose detection. Therefore, the glucose sensing material involved in the present invention has a wide range of application value in intelligent glucose detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0028] FIG1 is a cyclic voltammogram of the working electrode involved in Example 1 of the present application in PBS.

[0029] FIG2 is a time-current curve diagram of the working electrode involved in Example 2 of the present application in a 0-30 mM glucose PBS solution.

[0030] FIG3 is a microscope image of the cross section of the working electrode involved in Example 3 of the present application.

[0031] FIG4 is a sensitivity test diagram of the working electrode involved in the embodiment of the present application at different oxygen concentrations.

[0032] FIG5 is a test diagram of the response of the working electrode involved in Example 1 of the present application to the interfering substances acetaminophen and ascorbic acid. DETAILED DESCRIPTION

[0033] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0034] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. The reagents and raw materials used in the present invention can be purchased through conventional channels. Unless otherwise specified, the reagents and raw materials used in the present invention are used in accordance with conventional methods in the art or in accordance with the product instructions. In addition, any methods and materials similar to or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described in this patent are for illustrative purposes only.

[0035] Example 1# Working electrode 1#

[0036] The preparation of working electrode 1# includes the following steps:

[0037] (1) 5.2 g of a hydroxyl-terminated hyperbranched polyester (H104, hydroxyl value 520 mg KOH / g) was dissolved in 500 mL of acetone, followed by the addition of 45 mmol of glutaric anhydride and 2 mL of triethylamine as a catalyst; the mixed reaction solution was reacted in an oil bath at 60°C for 8 h, and the product was precipitated in an ethanolic sodium hydroxide solution. The precipitate was washed three times with ethanol and dried in a vacuum drying oven at 50°C for 48 h to obtain a carboxyl-terminated hyperbranched polymer H104-COOH;

[0038] (2) 1.1 g of the carboxyl-terminated hyperbranched polymer H104-COOH obtained in step 1) was added to 100 mL of PBS buffer solution, the pH value was adjusted to 4.5 using 0.1 M HCl solution, 0.47 mmol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.71 mmol of N-hydroxysuccinimide were added, and the mixture was stirred at room temperature for 20 min. Then, 0.365 g of a complex of N,N′-dimethyl-2,2′-biimidazole containing an amino functional group and osmium was added, and the mixture was stirred at room temperature for 48 h. After the reaction was completed, the mixture was dialyzed in deionized water for three days, during which the water was continuously changed. After the dialysis was completed, the mixture was freeze-dried to obtain a hyperbranched redox polymer;

[0039] (3) 20 μL of an aqueous solution (10 mg / mL) of the hyperbranched redox polymer obtained in step (2), 80 μL of a glucose oxidase solution (5 mg / mL), and 8 μL of a trimethylolpropane tris[3-(aziridine-1-yl)propionate crosslinker solution (5 mg / mL) were mixed evenly, and then drop-coated on the electrode surface. After the water evaporated, the mixture was vacuum-dried at 45°C for 48 h to obtain an electrode having a hyperbranched redox polymer glucose sensing layer.

[0040] (4) forming a semi-permeable polymer glucose limiting layer membrane on the electrode surface of the redox polymer glucose sensing layer having a hyperbranched structure obtained in step (3) by scraping, wherein the limiting layer membrane can be made of an existing glucose limiting membrane solution.

[0041] Example 2 Working electrode 2#

[0042] The preparation steps of working electrode 2# differ from those in Example 1 in that: in step (3), 200 μL of an aqueous solution (1 mg / mL) of the hyperbranched redox polymer obtained in step (2), 1 ml of a glucose oxidase solution (1 mg / mL), and 100 μL of a trimethylolpropane tris[3-(aziridine-1-yl)propionate crosslinker solution (1 mg / mL) were mixed uniformly and then drop-coated on the electrode surface. After the water evaporated, the mixture was vacuum-dried at 50°C for 60 h to obtain an electrode based on a hyperbranched redox polymer glucose sensing layer reagent.

[0043] The remaining steps are the same as those in Example 1.

[0044] Example 3 Working electrode 3#

[0045] The preparation steps of working electrode 3# differ from those in Example 1 in that: in step (3), 5 μL of an aqueous solution (20 mg / mL) of the hyperbranched redox polymer obtained in step 2, 1 μL of a glucose oxidase solution (10 mg / mL), and 0.1 μL of a trimethylolpropane tris[3-(aziridine-1-yl)propionate crosslinker solution (10 mg / mL) were mixed uniformly and then drop-coated on the electrode surface. After the water evaporated, the mixture was vacuum-dried at 20°C for 2 h to obtain an electrode based on a hyperbranched redox polymer glucose sensing layer reagent.

[0046] The remaining steps are the same as those in Example 1.

[0047] Example 4 Working electrode 4#

[0048] The preparation steps of working electrode 4# differ from those in Example 1 in that: in step (3), 20 μL of an aqueous solution (10 mg / mL) of the hyperbranched redox polymer obtained in step 2, 80 μL of a glucose oxidase solution (5 mg / mL), and 8 μL of a trimethylolpropane tris[3-(aziridine-1-yl)propionate crosslinker solution (5 mg / mL) were mixed uniformly and then drop-coated on the electrode surface. After the water evaporated, the mixture was vacuum-dried at 30°C for 16 h to obtain an electrode based on a hyperbranched redox polymer glucose sensing layer reagent.

[0049] The remaining steps are the same as those in Example 1.

[0050] Example 5 Working electrode 5#

[0051] The preparation steps of working electrode 5# differ from those in Example 1 in that: in step 1), 5.2 g of a hydroxyl-terminated hyperbranched polyester (H104, hydroxyl value 520 mg KOH / g) was dissolved in 500 mL of acetone, followed by the addition of 45 mmol of succinic anhydride and 2 mL of triethylamine catalyst; the mixed reaction solution was reacted in a 60°C oil bath for 8 h, the product was precipitated in an ethanolic sodium hydroxide solution, the precipitate was washed three times with ethanol, and then dried in a 50°C vacuum drying oven for 48 h to obtain a carboxyl-terminated hyperbranched polymer H104-COOH;

[0052] The remaining steps are the same as those in Example 1.

[0053] Example 6 Working electrode 6#

[0054] The preparation steps of working electrode 6# differ from those in Example 1 in that: in step 1), 5.2 g of a hydroxyl-terminated hyperbranched polyester (H104, hydroxyl value 520 mg KOH / g) was dissolved in 500 mL of acetone, followed by the addition of 45 mmol of maleic anhydride and 2 mL of a catalyst, triethylamine; the mixed reaction liquid was reacted in a 60°C oil bath for 8 h, the product was precipitated in an ethanolic sodium hydroxide solution, the precipitate was washed three times with ethanol, and then dried in a 50°C vacuum drying oven for 48 h to obtain a carboxyl-terminated hyperbranched polymer, H104-COOH;

[0055] The remaining steps are the same as those in Example 1.

[0056] Example 7 Working electrode 7#

[0057] The preparation steps of working electrode 7# are different from those of Example 1 in that: (2) 1.1 g of the carboxyl-terminated hyperbranched polymer H104-COOH obtained in step 1) is added to 100 mL of PBS buffer solution, the pH value is adjusted to 5 using 0.1 M HCl solution, 1.41 mmol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 2.12 mmol of N-hydroxysuccinimide are added, and the mixture is stirred at room temperature for 20 min. Then, 1.1 g of a complex of N,N′-dimethyl-2,2′-biimidazole containing an amino functional group and osmium is added, and the mixture is stirred at room temperature for 48 h. After the reaction is completed, the mixture is dialyzed in deionized water for three days, during which the water is continuously changed. After the dialysis is completed, the mixture is freeze-dried to obtain a hyperbranched redox polymer;

[0058] The remaining steps are the same as those in Example 1.

[0059] Example 8 Working electrode 8#

[0060] The preparation steps of working electrode 7# are different from those of Example 1 in that: (2) 1.1 g of the carboxyl-terminated hyperbranched polymer H104-COOH obtained in step 1) is added to 100 mL of PBS buffer solution, the pH value is adjusted to 4.5 using 0.1 M HCl solution, 0.14 mmol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.21 mmol of N-hydroxysuccinimide are added, and the mixture is stirred at room temperature for 20 min. Then, 0.11 g of a complex of N,N′-dimethyl-2,2′-biimidazole and osmium containing an amino functional group is added, and the mixture is stirred at room temperature for 48 h. After the reaction is completed, the mixture is dialyzed in deionized water for three days, during which the water is continuously changed. After the dialysis is completed, the mixture is freeze-dried to obtain a hyperbranched redox polymer;

[0061] The remaining steps are the same as those in Example 1.

[0062] Example 9 Working Electrode 9#

[0063] The difference between Example 9 and Example 1 is that a complex of N,N′-dimethyl-2,2′-biimidazole containing an amino functional group and ruthenium is used, and the rest are the same.

[0064] Comparative Example 1

[0065] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 uses a linear polyester polymer containing hydroxyl groups in the side chain instead of the terminal carboxyl hyperbranched polymer H104-COOH, and the linear polyester polymer containing hydroxyl groups in the side chain is a copolymer of hydroxyethyl methacrylate and vinyl pyrrolidone.

[0066] Experimental Example 1

[0067] The working electrode obtained in Example 1 was immersed in PBS and a potential scan was performed to obtain the cyclic voltammogram of the working electrode involved in Example 1 in PBS in Figure 1; the time-current curve of the working electrode obtained in Example 2 was measured in a 0-30mM glucose PBS solution to obtain the time-current curve graph in Figure 2; the cross section of the working electrode obtained in Example 3 was placed under a microscope for observation to obtain a photograph of the cross section of the working electrode under a microscope in Figure 3.

[0068] As shown in Figure 1, the redox potential of the hyperbranched redox polymer on the working electrode obtained in Example 1 of the present application is relatively low, which can avoid interference from interfering substances such as acetaminophen and ascorbic acid, making the detection results more accurate and sensitive; as shown in Figure 2, in the glucose concentration range of 0 to 30 mM glucose, the current value is linearly related to the glucose concentration, the glucose response is good, and glucose can be specifically detected, and its stable current signal has a high linear correlation coefficient with the glucose concentration; as shown in Figure 3, it can be seen from the photograph of the cross-section of the working electrode in Example 3 under a microscope that the hyperbranched redox polymer has excellent fluidity and film-forming properties, which makes the enzyme film layer smooth, which is beneficial to ensure the sensitivity consistency of the electrode produced in batches.

[0069] Experimental Example 2

[0070] The sensitivity of the working electrodes prepared in Example 1 and Comparative Example 1 was tested under different oxygen concentrations.

[0071] Test method: Place the working electrode in a 10mM glucose PBS solution with a 5% oxygen concentration. Measure the electrode's current. Once the current stabilizes, replace it with a 10mM glucose PBS solution with a 1% oxygen concentration and continue testing until the current stabilizes. The test results are shown in Figure 4.

[0072] As can be seen from Figure 4, the current value measured by the working electrode of Example 1 at 10mM glucose concentration with 1% and 5% oxygen concentration changes little, while the current value measured by the working electrode of Comparative Example 1 at 10mM glucose concentration with 1% and 5% oxygen concentration changes greatly, indicating that the working electrode of Example 1 reduces the competitive interference effect of oxygen and has a lower oxygen effect problem compared with the working electrode of Comparative Example 1.

[0073] Experimental Example 3

[0074] Response test diagram of the working electrode prepared in Example 1 to the interfering substances acetaminophen and ascorbic acid.

[0075] Testing method: The working electrode was placed in a 3.3mM glucose PBS solution, a 3.3mM glucose and 20mg / dL acetaminophen PBS solution, a 3.3mM glucose PBS solution, a 3.3mM glucose and 6mg / dL ascorbic acid PBS solution, and a 3.3mM glucose PBS solution, and the electrode current was measured. After the electrode was tested in each test solution for 2000 seconds until the current value stabilized, the electrode was replaced with the next test solution and tested again. This cycle was repeated. The test results are shown in Figure 5.

[0076] As shown in Figure 5, the working current of the working electrode of Example 1 changes little in the presence of the interfering substances acetaminophen and ascorbic acid. This indicates that the working electrode of Example 1 can eliminate the influence of the interfering substances acetaminophen and ascorbic acid on glucose detection and has good anti-interference performance.

[0077] The above embodiments are intended only to illustrate the technical concepts and features of this application. Their purpose is to enable those familiar with the art to understand the content of this application and implement it accordingly. They are not intended to limit the scope of protection of this application. Any equivalent changes or modifications made in accordance with the spirit of this application shall be included in the scope of protection of this application.

Claims

1. A method for preparing a hyperbranched redox polymer, wherein: The following steps are involved: Using cyclic dianhydride compounds to modify the hydroxyl-terminated hyperbranched polymer to obtain the carboxyl-terminated hyperbranched polymer; The carboxyl-terminated hyperbranched polymer is coupled with a redox ligand containing an amino functional group to obtain the hyperbranched structure redox polymer.

2. The preparation method according to claim 1, wherein The weight ratio of the carboxyl-terminated hyperbranched polymer to the redox ligand containing an amino functional group is 10:1-1:

1.

3. The preparation method according to claim 2, wherein The weight ratio of the carboxyl-terminated hyperbranched polymer to the redox ligand containing an amino functional group is 3:

1.

4. The preparation method according to claim 1, wherein The redox ligand containing an amino functional group is a complex of a bidentate nitrogen heterocyclic compound and a metal ion.

5. The preparation method according to claim 4, wherein The bidentate nitrogen heterocyclic compound is N,N′-dimethyl-2,2′-biimidazole; and the metal ion is osmium or ruthenium.

6. The preparation method according to claim 1, wherein The cyclic dianhydride compound includes at least one of maleic anhydride, glutaric anhydride, succinic anhydride, itaconic anhydride and adipic anhydride; and / or The terminal hydroxyl hyperbranched polymer is a terminal hydroxyl hyperbranched polyester and / or a terminal hydroxyl hyperbranched polyether.

7. The preparation method according to claim 6, wherein: The cyclic dianhydride compound is glutaric anhydride.

8. The preparation method according to claim 6, wherein: The terminal hydroxyl hyperbranched polymer is a terminal hydroxyl hyperbranched polyester.

9. A hyperbranched redox polymer, wherein: The hyperbranched redox polymer is prepared by the preparation method according to any one of claims 1 to 8.

10. A method for preparing a glucose sensing material, wherein: The glucose sensing material is obtained by a covalent cross-linking reaction of an aqueous solution of the hyperbranched redox polymer according to claim 9, a glucose oxidase solution, and a cross-linking agent solution.

11. The preparation method according to claim 10, wherein: The reaction temperature of the covalent cross-linking reaction is 20 to 50° C., and the reaction time is 1 to 60 hours.

12. The preparation method according to claim 11, wherein The reaction temperature of the covalent cross-linking reaction is 45° C. and the reaction time is 48 h.

13. The preparation method according to claim 10, wherein: The concentration of the aqueous solution of the hyperbranched redox polymer is 1-20 mg / mL, the concentration of the glucose oxidase solution is 1-10 mg / mL, and the concentration of the cross-linking agent solution is 1-10 mg / mL; the mass ratio of the hyperbranched redox polymer, glucose oxidase, and cross-linking agent is 1:(0.1-5):(0.01-0.5).

14. A glucose sensing material, wherein: The glucose sensing material is prepared by the preparation method according to any one of claims 10 to 13.

15. Use of the glucose sensing material according to claim 14 in a glucose intelligent monitoring instrument and a diabetes management instrument.

Images