Glucose monitoring probe and preparation method thereof

Abstract

The invention discloses a glucose monitoring probe and a preparation method thereof, the glucose monitoring probe comprises a working electrode, the working electrode is provided with a sensing layer, the sensing layer comprises glucolase and a redox polymer, and the redox polymer has a structure as shown in a formula (1): # imgabs0 #, a1 and A2 are the same and are selected from any one of 4-vinylpyridine and N-vinyl imidazole, and A3 is methacrylate quaternary ammonium salt. According to the invention, the glucose monitoring probe with high sensitivity and strong anti-interference capability and the preparation method thereof can be provided.

Description

Technical Field

[0001] The present disclosure generally relates to the field of cutting-edge new materials, and more particularly to a glucose monitoring probe and a method for preparing the same. Background Art

[0002] Diabetes is a metabolic disease characterized by high blood sugar. There is currently no cure. Diabetic patients often use glucose sensors to dynamically monitor their blood sugar, which helps control the disease and monitor blood sugar in a timely manner.

[0003] Glucose sensors generally include a sensor probe and a processing device that records the sensing information. When performing dynamic blood glucose monitoring, the sensor probe is often buried under the skin of the subject. A sensing layer is provided on the working electrode of the probe. The glucose at the implanted site contacts and reacts with the sensing layer on the working electrode to generate an electrical signal. The processing device processes the electrical signal to obtain physiological parameter information associated with the blood glucose concentration level. The sensing layer on the working electrode is generally formed by dripping a sensing layer solution on the surface of the working electrode and then solidifying it. The sensing layer solution usually includes glucose enzymes and electron mediators composed of redox polymers.

[0004] However, the redox polymers used in the existing sensing layer solutions are usually poorly water-soluble, which is not conducive to drip coating, and the use of mixed solvents of organic solvents and water usually affects the enzymatic activity of glucose enzymes, which may affect the long-term stability of the working electrode. In addition, the redox equilibrium potential of the existing redox polymers is relatively high. When the working voltage is applied to the working electrode, some interfering substances in the subject's body (such as uric acid and acetaminophen, etc.) are also prone to redox reactions at higher potentials, resulting in interference with the electrical signals generated by the redox reaction of glucose molecules. Summary of the invention

[0005] The present disclosure is proposed in view of the above situation, and its purpose is to provide a glucose monitoring probe with high sensitivity and strong anti-interference ability and a preparation method thereof.

[0006] To this end, the first aspect of the present disclosure provides a glucose monitoring probe, the glucose monitoring probe comprising a working electrode, a sensing layer disposed on the working electrode, the sensing layer comprising glucose enzyme and a redox polymer, the redox polymer having a structure as shown in the following formula (1):

[0007]

[0008] Wherein, A1 and A2 are the same and are selected from any one of 4-vinylpyridine and N-vinylimidazole, A3 is a quaternary ammonium salt of methacrylate, and X has a structure shown in the following formula (2):

[0009]

[0010] Wherein, M is osmium, L1, L2, L3, L4, L5 and L6 are nitrogen-containing heterocyclic ligands, and are combined in pairs to form three bidentate ligands, and the three bidentate ligands include at least two imidazole-pyridine ligands; n1, n2 and n3 are the same or different and are any natural number from 100 to 1000.

[0011] In the glucose monitoring probe involved in the first aspect of the present disclosure, the sensing layer arranged on the working electrode includes a redox polymer shown in formula (1), and the redox polymer includes a quaternary ammonium cation, which can improve the water solubility of the polymer as a whole, and make the surface of the polymer positively charged, which is beneficial to the coating process (especially the drop coating process), and on the other hand, it can also make the surface of the polymer with positive charge have a stronger electrostatic interaction with the surface of the negatively charged glucose enzyme, thereby improving the electron transfer efficiency, and then can improve the sensitivity of the probe; in addition, since X includes at least 2 imidazole-pyridine ligands, the redox polymer can have a lower redox equilibrium potential, so that the working potential required for the glucose to contact the sensing layer on the working electrode to react is lower, and then can effectively reduce the redox reaction of high potential interferers, and reduce the interference of high potential interferers on the electrical signal generated by the redox reaction of glucose molecules. Thus, a glucose monitoring probe with high sensitivity and strong anti-interference ability can be provided.

[0012] In addition, in the glucose monitoring probe involved in the first aspect of the present disclosure, optionally, X has a structure as shown in the following formula (3):

[0013]

[0014] Wherein, Y is a halogen ion, and n4 is any natural number from 2 to 5. In this case, the halogen ion can balance the charge of the metal complex X, and the halogen ion is also hydrophilic, which can further improve the water solubility of the redox polymer.

[0015] In addition, in the glucose monitoring probe involved in the first aspect of the present disclosure, optionally, X has a structure as shown in the following formula (4):

[0016]

[0017] Wherein, R1, R2, R3, R4, R5 and R6 are the same or different and are independently selected from hydrogen, methyl, methoxy, trifluoromethyl or amino. In this case, by adjusting the substituents at the positions of R1, R2, R3, R4, R5 and R6 and selecting imidazole-imidazole as a ligand, the potential of the redox polymer can be within a predetermined range, thereby improving the anti-interference ability of the glucose monitoring probe.

[0018] In addition, in the glucose monitoring probe involved in the first aspect of the present disclosure, optionally, X has a structure as shown in the following formula (5):

[0019]

[0020] Among them, R7, R8, R9, R 10 , R 11 , R 12 and R 13 are the same or different and are independently selected from hydrogen, methyl, methoxy, trifluoromethyl or amino. In this case, by adjusting R7, R8, R9, R 10 , R 11 , R 12 and R 13 The substituents at the sites and the selection of imidazole-pyridine as ligands can make the potential of the redox polymer within a predetermined range, thereby improving the anti-interference ability of the glucose monitoring probe.

[0021] In addition, in the glucose monitoring probe involved in the first aspect of the present disclosure, optionally, A2 and X are covalently bonded via an amide bond by dehydration condensation, and the connection between A2 and X has a structure shown in formula (6):

[0022]

[0023] Wherein, n5 is the number of hydrocarbon chains between the amide bond and A2, and is any natural number from 1 to 10; n6 is the number of hydrocarbon chains between the amide bond and X, and is any natural number from 1 to 10. In this case, the stability of the connection between A2 and X can be improved by dehydration condensation.

[0024] In addition, in the glucose monitoring probe involved in the first aspect of the present disclosure, optionally, L1, L2, L3, L4, L5 and L6 are independently selected from any one of pyridine, imidazole, pyrimidine, thiazole and pyrrole. In this case, by changing the type of ligand, the potential of the redox polymer can be within a predetermined range, thereby improving the anti-interference ability of the glucose monitoring probe.

[0025] In addition, the second aspect of the present disclosure provides a method for preparing a glucose monitoring probe, the glucose monitoring probe comprising a working electrode, the preparation method comprising: reacting a nitrogen-containing heterocyclic compound and a methacrylate quaternary ammonium salt to generate a first polymer containing a quaternary ammonium salt, wherein the nitrogen-containing heterocyclic compound is selected from any one of 4-vinylpyridine and N-vinylimidazole; and grafting a metal complex X onto the first polymer to obtain a redox polymer as shown in the following formula (1):

[0026]

[0027] Wherein, A1 and A2 are the same and are selected from any one of 4-vinylpyridine and N-vinylimidazole, A3 is a quaternary ammonium salt of methacrylate, and the metal complex X has a structure shown in the following formula (2):

[0028]

[0029] in,

[0030] M is osmium, L1, L2, L3, L4, L5 and L6 are nitrogen-containing heterocyclic ligands, and are combined in pairs to form three bidentate ligands, and the three bidentate ligands include at least two imidazole-pyridine ligands; n1, n2 and n3 are the same or different and are any natural number from 100 to 1000; a sensing layer solution including the redox polymer, glucose enzyme and a cross-linking agent is prepared; the sensing layer solution is drop-coated on the surface of the working electrode to form a sensing layer, and a glucose monitoring probe including the redox polymer is obtained.

[0031] In the preparation method of the glucose monitoring probe involved in the second aspect of the present disclosure, the sensing layer arranged on the working electrode includes the redox polymer shown in formula (1), and the redox polymer includes a quaternary ammonium cation, which can improve the water solubility of the polymer as a whole, and make the surface of the polymer positively charged, which is beneficial to the coating process (especially the drop coating process), and on the other hand, it can also make the surface positively charged polymer and the surface negatively charged glucose enzyme have a stronger electrostatic interaction, thereby improving the electron transfer efficiency, and then the sensitivity of the probe can be improved; in addition, since X includes at least 2 imidazole-pyridine ligands, the redox polymer can have a lower redox equilibrium potential, so that the working potential required for the glucose to contact the sensing layer on the working electrode to react is lower, and then the redox reaction of the high potential interferer can be effectively reduced, and the interference of the electrical signal generated by the redox reaction of the glucose molecule by the high potential interferer can be reduced. Thus, a glucose monitoring probe with high sensitivity and strong anti-interference ability can be prepared by the preparation method involved in the present disclosure.

[0032] In addition, in the preparation method involved in the second aspect of the present disclosure, optionally, the step of grafting the metal complex X to the first polymer includes: selecting the metal complex X with a free amino group; modifying the first polymer so that the first polymer forms a side chain including a carboxyl group; and covalently bonding the first polymer and the metal complex X through an amide bond by dehydration condensation, wherein the connection between the first polymer and X has a structure shown in formula (6):

[0033]

[0034] Wherein, n5 is the number of hydrocarbon chains between the amide bond and A2, and is any natural number from 1 to 10; n6 is the number of hydrocarbon chains between the amide bond and X, and is any natural number from 1 to 10. In this case, the stability of the metal complex X grafted to the first polymer can be improved by dehydration condensation.

[0035] In addition, in the preparation method involved in the second aspect of the present disclosure, optionally, the metal complex X has a structure shown in the following formula (3):

[0036]

[0037] Here, Y is a halogen ion, and n4 is any natural number from 2 to 5. In this case, the halogen ions can balance the charge of the metal complex X, thereby improving the water solubility of the redox polymer.

[0038] According to the present disclosure, a glucose monitoring probe with high sensitivity and strong anti-interference ability and a preparation method thereof can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present disclosure will now be explained in further detail, by way of example only, with reference to the accompanying drawings.

[0040] Figure 1 is a schematic diagram showing the usage status of the glucose monitoring probe involved in the example of the present disclosure.

[0041] Figure 2 is a schematic diagram showing the structure of a glucose monitoring probe involved in the example of the present disclosure.

[0042] Figure 3 It shows Figure 2 A schematic diagram of the structure of the glucose monitoring probe involved in a bent state.

[0043] Figure 4 Schematic diagram showing the reaction between the glucose monitoring probe and glucose involved in the example of the present disclosure.

[0044] Figure 5 is a flow chart showing a method for preparing a glucose monitoring probe according to an example of the present disclosure.

[0045] Figure 6 2 is a cyclic voltammetry graph showing the probe of Example 1 after 200 cycles.

[0046] Figure 7 FIG. 4 is a graph showing the oxidation peak current-cycle number curve of the probe of Example 1. FIG.

[0047] Figure 83 is a graph showing the oxidation peak current-storage days curve of the probe of Example 1.

[0048] Fig. 9 3 is a graph showing the sensitivity response of the probe of Example 1 versus glucose concentration.

[0049] Fig.10 2 is a cyclic voltammetry graph showing the probe of Example 2 after 200 cycles.

[0050] Fig.11 FIG. 4 is a graph showing the oxidation peak current-cycle number curve of the probe of Example 2.

[0051] Fig.12 3 is a graph showing the oxidation peak current-storage days curve of the probe of Example 2.

[0052] Fig.13 3 is a graph showing the sensitivity response of the probe of Example 2 versus glucose concentration.

[0053] Fig.14 is a graph showing a cyclic voltammetry curve of the probe of Example 3.

[0054] Fig.15 3 is a graph showing the sensitivity response of the probe of Example 3 versus glucose concentration.

[0055] Fig.16 is a graph showing a cyclic voltammetry curve of the probe of Example 4.

[0056] Fig.17 3 is a graph showing the sensitivity response of the probe of Example 4 versus glucose concentration.

[0057] Fig.18 is a graph showing a cyclic voltammetry curve of the probe of Comparative Example 1.

[0058] Fig.19 is a graph showing the sensitivity response-glucose concentration curve of the probe of Comparative Example 1.

[0059] Fig. 20 is a graph showing a cyclic voltammetry curve of the probe of Comparative Example 2.

[0060] Fig.21 3 is a graph showing the sensitivity response-glucose concentration curve of the probe of Comparative Example 2.

[0061] Fig. 22 is a cyclic voltammetry graph showing the probe of Comparative Example 3.

[0062] Fig.23 3 is a graph showing the sensitivity response-glucose concentration curve of the probe of Comparative Example 3.

[0063] Description of reference numerals:

[0064] 1…glucose monitoring probe, 1a…connection part, 1b…implantation part, 10…working electrode, 110…sensing layer, 2…electronic system. DETAILED DESCRIPTION

[0065] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same symbols are assigned to the same components, and repeated descriptions are omitted. In addition, the accompanying drawings are only schematic diagrams, and the ratio of the dimensions of the components or the shapes of the components may be different from the actual ones.

[0066] It should be noted that the terms "including" and "having" and any variations thereof in the present disclosure, such as a process, method, system, product or device that includes or has a series of steps or units, are not necessarily limited to those steps or units clearly listed, but may include or have other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0067] The first aspect of the present disclosure relates to a glucose monitoring probe, which is a probe for monitoring glucose. In the present disclosure, the glucose monitoring probe can be referred to as a probe, a monitoring probe, a glucose probe, a glucose sensor, a blood sugar sensor, a sensor, or an implantable glucose monitoring probe.

[0068] A second aspect of the present disclosure relates to a method for preparing a glucose monitoring probe. The method for preparing a glucose monitoring probe may be referred to as a preparation method or a method for making a glucose monitoring probe.

[0069] The glucose monitoring probe involved in the first aspect of the present disclosure is described below in conjunction with the accompanying drawings.

[0070] Figure 1 is a schematic diagram showing the usage state of the glucose monitoring probe 1 involved in the example of the present disclosure. Figure 2 is a schematic diagram showing the structure of the glucose monitoring probe 1 involved in the example of the present disclosure. Figure 3 It shows Figure 2 A schematic structural diagram of the glucose monitoring probe 1 involved in a bent state.

[0071] In some examples, the portable glucose monitor may include a glucose monitoring probe 1 and an electronic system 2 connected to the glucose monitoring probe 1. In this case, by implanting the glucose monitoring probe 1 of the portable glucose monitor into a human body, such as a human body surface, the glucose monitoring probe 1 is in contact with tissue fluid or blood on the body surface, and the glucose monitoring probe 1 can be used to sense a sensing signal related to the glucose concentration of the tissue fluid or blood, and the sensing signal is transmitted to the electronic system 2, thereby obtaining the corresponding glucose concentration.

[0072] Specifically, a portion of the glucose monitoring probe 1 (especially the sensing portion) can be implanted, for example, on the surface of the human body and in contact with tissue fluid or blood in the body. In addition, another portion of the glucose monitoring probe 1 is also connected to an electronic system 2 located outside the body surface. When the portable glucose monitor is working, the glucose monitoring probe 1 reacts with the tissue fluid or blood in the body to generate a sensing signal (such as a current signal), and transmits the sensing signal to the electronic system 2 on the body surface. The electronic system 2 processes the sensing signal to obtain the glucose concentration. Although Figure 1 The glucose monitoring probe 1 is shown to be disposed on the arm, but the embodiment is not limited thereto. For example, the glucose monitoring probe 1 may also be disposed on the abdomen, waist, or leg.

[0073] In some examples, the glucose monitoring probe 1 can directly detect glucose in the blood or glucose in the tissue fluid. Since the glucose concentration in the tissue fluid is strongly correlated with the glucose concentration in the blood, the glucose concentration in the blood can also be obtained by measuring the glucose concentration in the tissue fluid.

[0074] In some examples, the glucose monitoring probe 1 may include a working electrode 10 (see Figure 2 In some examples, for convenience of description, the glucose monitoring probe 1 can be divided into a connecting portion 1a and an implanting portion 1b (see Figure 3 ). Figure 3 The straight line A-A' in the figure roughly shows the dividing line that divides the glucose monitoring probe 1 into a connecting part 1a and an implanting part 1b. Specifically, when the glucose monitoring probe 1 is implanted into the body surface, the connecting part 1a can be located outside the body surface, and the implanting part 1b can be implanted inside the body surface.

[0075] In some examples, the implantable portion 1b of the glucose monitoring probe 1 may include a working electrode 10 (see Figure 2 and Figure 3 ).

[0076] In some examples, the working electrode 10 may include a sensing layer 110 (see Figure 2). Thus, the analyte level can be detected through the sensing layer 110. In some examples, the working electrode 10 may include a substrate layer. In some examples, the sensing layer 110 may be formed by coating a sensing layer solution on the substrate layer. In some examples, the sensing layer solution may be formed into the sensing layer 110 by at least one process such as spin coating, dip coating, drop coating, or spray coating.

[0077] In some examples, the sensing layer solution can be dripped on the working electrode 10 in the form of multiple discrete points to form the sensing layer 110. In some examples, multiple discrete points constitute the sensing layer 110. In some examples, multiple points with overlapping edges can also be dripped on the working electrode 10 to form a sensing layer 110 in which multiple points are connected in a line. In this case, it is convenient to set more sensing layer solutions on the working electrode 10, which can help improve the sensitivity of the working electrode 10.

[0078] In some examples, the sensing layer solution may include a redox polymer. In some examples, the sensing layer solution may include a glucose enzyme. In some examples, the glucose enzyme may be a glucose oxidase or a glucose dehydrogenase.

[0079] Figure 4 Schematic diagram showing the reaction between the glucose monitoring probe 1 and glucose involved in the example of the present disclosure.

[0080] The following, combined Figure 4 , to GO X The reaction occurring in the sensing layer 110 of the working electrode 10 is explained by taking (FAD) as glucose oxidase and MED as metal oxide as an example.

[0081] In the sensing layer 110 of the working electrode 10, when GO X When (FAD) encounters glucose in tissues, the following reactions occur:

[0082] Glucose + GOx(FAD) → Gluconolactone + GOx(FADH2) ... Reaction formula (I)

[0083] GOx(FADH2)+MED ox →GOx(FAD)+MED red ……Reaction formula (II)

[0084]

[0085] In the above reaction process, it can be seen that in the chemical reaction, glucose is oxidized by glucose oxidase GOx (FAD) to generate gluconolactone and reduced glucose oxidase GOx (FADH2) (reaction formula (I)); reduced glucose oxidase GOx (FADH2) and oxidized metal oxide MED ox Reaction to generate reduced metal oxide MED red At the same time, the reduced glucose oxidase GOx(FADH2) is oxidized to glucose oxidase GOx(FAD) (reaction formula (II)); by applying a working voltage to the working electrode 10, the reduced metal oxide MED red Oxidized to metal oxide MED ox , and electrons are generated at the same time (reaction formula (III)).

[0086] Through the above reaction formula (I) to reaction formula (III), the reaction between the sensing layer 110 and glucose can be continuously carried out. Figure 4 The reaction process is only schematically shown in FIG. 1 , and does not mean that the structure of the sensing layer 110 disclosed in the present invention can only be used with Figure 4 As in the above, it should not be understood as limiting the structure of the sensing layer 110 of the present disclosure.

[0087] In some examples, as described above, the probe 1 may include a working electrode 10 , and a sensing layer 110 may be disposed on the working electrode 10 .

[0088] In some examples, the sensing layer 110 may include glucose enzyme. The glucose enzyme may be glucose oxidase or glucose dehydrogenase.

[0089] In some examples, the sensing layer 110 may include a redox polymer. In some examples, the redox polymer may have a low redox equilibrium potential (hereinafter referred to as the redox equilibrium potential). In this case, the redox polymer containing a low potential in the sensing layer 110 can reduce the working voltage required for the working electrode 10 to work normally, thereby reducing the interference of the electrochemical reaction of the electroactive substances under a part of the high voltage to generate the current on the working electrode 10. In other words, by providing a low potential redox polymer on the sensing layer 110, it is possible to play an anti-interference role against high potential interferers.

[0090] In some examples, the potential of the redox polymer can be -100mV to 100mV. In some examples, a high potential interferer refers to an interfering substance with an oxidation potential greater than 100mV. For example, high potential interferers may include uric acid, acetaminophen, ibuprofen, and acetylsalicylic acid. It is understandable that the probability of a substance with a potential of 150mV reacting when the operating voltage is 0mV to 100mV is much lower than the probability of a substance reacting when the operating voltage is 100mV to 200mV. Therefore, the lower the potential of the redox polymer, the stronger the anti-interference effect against high potential interferers.

[0091] In some examples, preferably, the potential of the redox polymer may be -50 mV to 50 mV. When the potential of the redox polymer is -50 mV to 50 mV, the working electrode 10 has a more significant anti-interference effect on high potential interferers such as uric acid, acetaminophen, ibuprofen and acetylsalicylic acid.

[0092] Hereinafter, the specific structure of the redox polymer will be described in detail.

[0093] In some examples, the redox polymer may have a structure as shown in formula (1):

[0094]

[0095] In some examples, A1 and A2 may be nitrogen-containing heterocyclic compounds. In some examples, A1 and A2 may be selected from any one of pyridine derivatives and imidazole derivatives. In some examples, A1 and A2 may be selected from any one of 4-vinylpyridine and N-vinylimidazole. In some examples, A1 and A2 may be the same. In some examples, n1 may be any natural number from 100 to 1000. For example, n1 may be 100, 300, 500, 700, 900 or 1000. In some examples, n2 may be any natural number from 100 to 1000. For example, n2 may be 100, 300, 500, 700, 900 or 1000. In some examples, n1 and n2 may be the same or different and may be any natural number from 100 to 1000.

[0096] In some examples, X may be a metal complex (hereinafter referred to as X). In some examples, X may have a structure as shown in the following formula (2):

[0097]

[0098] In some examples, M may be a transition metal. In some examples, M may be selected from any one of osmium, nickel, chromium, iridium, and ruthenium. In some examples, M may be osmium.

[0099] In some examples, X may have six ligands. In some examples, in the chemical structure examples in which X includes multiple ligands, the dotted line represents the coordination bond formed between the ligand and M. In some examples, the six ligands may be L1, L2, L3, L4, L5, and L6. In some examples, L1, L2, L3, L4, L5, and L6 may be the same or different. In some examples, L1, L2, L3, L4, L5, and L6 may be any one of a nitrogen-containing heterocycle, a halogen atom, a water molecule, an ammonia molecule, or a carbon monoxide molecule. In this case, by changing the type of ligand, the potential of the redox polymer can be within a predetermined range, thereby improving the anti-interference ability of the glucose monitoring probe 1.

[0100] In some examples, L1, L2, L3, L4, L5 and L6 can be nitrogen-containing heterocyclic ligands. In this case, a coordination bond is formed between the nitrogen atom in the ligand and M, further enhancing the binding energy between the ligand and M, thereby improving the stability of the chemical structure of the metal complex X.

[0101] In some examples, L1, L2, L3, L4, L5 and L6 can be selected from any one of pyridine derivatives and imidazole derivatives. In this case, by changing the type and composition of the ligands in the metal complex X, the redox equilibrium potential of the redox polymer can be changed, and the redox polymer having a redox equilibrium potential within a predetermined range can be further obtained by screening.

[0102] In some examples, L1, L2, L3, L4, L5 and L6 can be independently selected from any one of pyridine, imidazole, pyrimidine, thiazole and pyrrole. In some examples, preferably, L1, L2, L3, L4, L5 and L6 can be independently selected from any one of pyridine and imidazole. In some examples, L1, L2, L3, L4, L5 and L6 can contain free groups. In some examples, the free groups can be amino or carboxyl.

[0103] In some examples, X may include a single ligand and / or a bidentate ligand. "X may include a single ligand and / or a bidentate ligand" means that X may include a single ligand, X may include both a single ligand and a bidentate ligand, and X may include a bidentate ligand. Specifically, L1, L2, L3, L4, L5, and L6 may all be single ligands, and any two adjacent ligands among L1, L2, L3, L4, L5, and L6 may also be combined into a bidentate ligand.

[0104] In some examples, a bidentate ligand may be a ligand containing two coordinating atoms in one ligand. In some examples, a monodentate ligand may be a ligand containing one coordinating atom in one ligand.

[0105] In some examples, L1, L2, L3, L4, L5 and L6 can be combined in pairs to form a bidentate ligand. In some examples, L1, L2, L3, L4, L5 and L6 can be combined in pairs to form three bidentate ligands. In this case, by changing the number of bidentate ligands in the ligand, a redox polymer with a redox equilibrium potential within a predetermined range can be further obtained.

[0106] In some examples, X may include an imidazole-pyridine ligand. For example, X may include 1, 2 or 3 imidazole-pyridine ligands. In this case, the potential of the redox polymer can be adjusted by changing the number of bidentate ligands in the ligand. In some examples, X may include at least 2 imidazole-pyridine ligands. In other words, at least 2 imidazole-pyridine ligands are included in the 3 bidentate ligands of X. In this case, the redox polymer can have a lower redox equilibrium potential, so that the working potential required for the glucose to contact and react with the sensing layer 110 on the working electrode 10 is lower, thereby effectively reducing the redox reaction of high potential interferers and reducing the interference of high potential interferers on the electrical signal generated by the redox reaction of the glucose molecule.

[0107] In some examples, X may have a structure as shown in formula (3):

[0108]

[0109] In some examples, Y can be a halogen ion. In some examples, the halogen ion can be selected from any one of fluoride ion, chloride ion, bromide ion or iodide ion. In this case, the charge of the metal complex X can be balanced by the halogen ion, and the halogen ion is also hydrophilic, which can further improve the water solubility of the redox polymer.

[0110] In some examples, n4 may be any natural number from 2 to 5. For example, n4 may be 2, 3, 4 or 5. In some examples, X may have a structure as shown in the following formula (4):

[0111]

[0112] In some examples, as shown in formula (4), X may include an imidazole-imidazole ligand, and R1, R2, R3, R4, R5, and R6 are substituents at different positions on the imidazole-imidazole ligand.

[0113] In some examples, R1, R2, R3, R4, R5 and R6 may be the same or different. In some examples, R1, R2, R3, R4, R5 and R6 may be independently selected from hydrogen, methyl, methoxy, trifluoromethyl or amino. In other words, R1 may be selected from hydrogen, methyl, methoxy, trifluoromethyl or amino, R2 may be selected from hydrogen, methyl, methoxy, trifluoromethyl or amino, R3 may be selected from hydrogen, methyl, methoxy, trifluoromethyl or amino, R4 may be selected from hydrogen, methyl, methoxy, trifluoromethyl or amino, R5 may be selected from hydrogen, methyl, methoxy, trifluoromethyl or amino, and R6 may be selected from hydrogen, methyl, methoxy, trifluoromethyl or amino.

[0114] In this case, by adjusting the substituents at the R1, R2, R3, R4, R5 and R6 positions and selecting imidazole-imidazole as a ligand, the potential of the redox polymer can be kept within a predetermined range, thereby improving the anti-interference ability of the glucose monitoring probe 1.

[0115] In some examples, X has a structure as shown in formula (5):

[0116]

[0117] In some examples, as shown in formula (5), X may include an imidazole-pyridine ligand, R7, R8, R9, R 10 , R 11 , R 12 and R 13 are substituents at different positions on the imidazole-pyridine ligand. 10 , R 11 , R 12 and R 13 can be the same or different. In some examples, R7, R8, R9, R 10 , R 11 , R 12 and R 13 can be independently selected from hydrogen, methyl, methoxy, trifluoromethyl or amino. In this case, by adjusting R7, R8, R9, R 10 , R 11 , R 12 and R 13 The substituents at the sites and the selection of imidazole-pyridine as ligands can make the potential of the redox polymer within a predetermined range, thereby improving the anti-interference ability of the glucose monitoring probe 1.

[0118] In some examples, in the example where X includes multiple imidazole-pyridine ligands, the structure and group selection shown in formula (5) can be referred to, and the substituents on each imidazole-pyridine ligand can be the same or different.

[0119] In some examples, X can be grafted onto A2. In some examples, X can be grafted onto A2 by chemically reacting A2 and X to form a functional group. In this case, the stability of the connection between A2 and X can be improved by forming a functional group between A2 and X, thereby improving the overall stability of the redox polymer.

[0120] In some examples, X and A2 can be covalently bonded by dehydration condensation. In some examples, X and A2 can be bonded by an amide bond or an ester bond. In some examples, preferably, X and A2 can be bonded by an amide bond. In this case, the stability of the connection between A2 and X can be improved by dehydration condensation.

[0121] In some examples, the connection between X and A2 may have a structure as shown in formula (6):

[0122]

[0123] In some examples, n5 can be the number of hydrocarbon chains between the amide bond and A2. In some examples, n6 can be the number of hydrocarbon chains between the amide bond and X. In some examples, n5 can be any natural number from 1 to 10. For example, n5 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some examples, n6 can be any natural number from 1 to 10. For example, n6 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some examples, n5 and n6 can be the same or different.

[0124] In other examples, X and A2 can be linked via a disubstituted triazole group.

[0125] In some examples, the redox polymer may be a random copolymer. In some examples, the random copolymer may be a polymer formed by random copolymerization of two or more different monomers, wherein the polymerization positions of the monomers may be random and the arrangement of the monomers in the structure of the random copolymer may be disordered. In some examples, the random copolymer may have no obvious repeating units or structural units.

[0126] Specifically, in the polymerization reaction of A1, A2 and A3, A1, A2 and A3 may be connected in no order. The n1, n2 and n3 in the chemical structure shown in formula (1) only indicate that the main chain of the redox polymer includes n1 A1, n2 A2 and n3 A3. The monomers A1, A2 and A3 in the main chain may be copolymerized and connected in no order. That is to say, formula (1) does not mean that the redox polymer can only be connected by copolymerization in sequence with n1 A1, n2 A2 and n3 A3, but n1 A1, n2 A2 and n3 A3 can be connected randomly. For example, 1 A1, n3 A3, n2 A2 and (n1-1) A1 can be connected by copolymerization in sequence, 6 A3, n1 A1, n2 A2 and (n3-6) A3 can be connected by copolymerization in sequence, and n2 A2, n3 A3 and n1 A1 can be connected by copolymerization in sequence.

[0127] In some examples, the main chain of the redox polymer may have a structure as shown in Formula (7):

[0128]

[0129] In some examples, X can be connected to the main chain of the polymer. In some examples, when X is connected to the main chain of the polymer, the main chain of the polymer needs to be modified. Since A1 and A2 are selected from the same monomer, the monomer to be modified during the modification is A2 to which X can be connected. In other words, A2 is grafted with the metal complex X, and A1 is not grafted with the metal complex X.

[0130] In some examples, A3 may carry a positively charged group. In this case, the surface of the redox polymer can be positively charged, and there is a stronger electrostatic interaction between the redox polymer with a positive charge on the surface and the glucose enzyme with a negative charge on the surface, which is conducive to improving the efficiency of electron transfer and further improving the sensitivity of the probe 1.

[0131] In some examples, the redox polymer may include a hydrophilic group. In this case, the water solubility of the redox polymer as a whole can be improved, which is beneficial for coating processing (especially drop coating process). In some examples, the hydrophilic group can be any one of a quaternary ammonium group, a sulfonic acid group, and a carboxylic acid group.

[0132] In some examples, A3 can be a quaternary ammonium salt compound or a zwitterionic compound. In some examples, the quaternary ammonium salt compound can be any one of methacrylate quaternary ammonium salt, vinyl quaternary ammonium salt, alkyl trimethyl quaternary ammonium salt, hexadecyl trimethyl quaternary ammonium salt and dialkyl quaternary ammonium salt.

[0133] In some examples, the zwitterionic compound can be any one of sulfonated betaine, carboxylated betaine and 2-methacryloyloxyethyl phosphorylcholine. In this case, the quaternary ammonium salt compound contains a quaternary ammonium cation (i.e., a positively charged group and a hydrophilic group at the same time), and the zwitterionic compound also includes a positively charged group and a hydrophilic group at the same time. The quaternary ammonium salt compound or zwitterionic compound is used as part of the main chain of A3 to make the surface of the redox polymer positively charged, and at the same time, the water solubility of the redox polymer as a whole can be improved, which is convenient for drop coating processing and improves the sensitivity of the probe 1.

[0134] In some examples, preferably, A3 can be a quaternary ammonium salt compound. In this case, the redox polymer contains quaternary ammonium cations, which can improve the water solubility of the redox polymer as a whole and make the surface of the redox polymer positively charged, thereby improving the sensitivity of the probe 1.

[0135] In some examples, preferably, A3 can be a quaternary ammonium salt of methacrylate. In this case, the water solubility of the redox polymer as a whole and the sensitivity of the probe 1 can be further improved.

[0136] In some examples, n3 can be any natural number from 100 to 1000. For example, n3 can be 100, 300, 500, 700, 900 or 1000. In some examples, n1 and n3 are the same or different and are any natural number from 100 to 1000. In some examples, n2 and n3 are the same or different and are any natural number from 100 to 1000. In some examples, n1, n2 and n3 are the same or different and are any natural number from 100 to 1000.

[0137] In some examples, the water solubility of the redox polymer can be changed by adjusting the percentage of monomer A3 in the main chain of the redox polymer (i.e., the chemical structure shown in formula (7)) to the total number of monomers (A1, A2, and A3) in the main chain (the percentage is the percentage of the value of n3 / (n1+n2+n3)). In this case, the greater the percentage of A3, the higher the content of A3 in the monomers of the main chain of the redox polymer, and the better the water solubility of the redox polymer.

[0138] In some examples, monomer A3 may account for 5% to 50% of the main chain. For example, monomer A3 may account for 5%, 15%, 25%, 35%, 45% or 50% of the main chain.

[0139] In some examples, preferably, A1 and A2 in the redox polymer may be the same and selected from any one of 4-vinylpyridine and N-vinylimidazole, A3 may be a quaternary ammonium salt of methacrylate, and X may have a structure as shown in the following formula (2):

[0140]

[0141] Wherein, M can be osmium, L1, L2, L3, L4, L5 and L6 can be nitrogen-containing heterocyclic ligands, and they are combined in pairs to form three bidentate ligands, and the three bidentate ligands include at least two imidazole-pyridine ligands; n1, n2 and n3 can be the same or different and can be any natural number from 100 to 1000.

[0142] In this case, the redox polymer contains quaternary ammonium cations, which can improve the water solubility of the polymer as a whole and make the surface of the polymer positively charged, which is beneficial to drip coating on the one hand, and can also make the polymer with positive charge on the surface and the glucose enzyme with negative charge on the surface have stronger electrostatic interaction, thereby improving the electron transfer efficiency; in addition, since X includes at least two imidazole-pyridine ligands, the redox polymer can have a lower redox equilibrium potential, so that the working potential required for glucose to contact and react with the sensing layer 110 on the working electrode 10 is lower, thereby effectively reducing the redox reaction of high potential interferents and reducing the interference of high potential interferents on the electrical signal generated by the redox reaction of glucose molecules.

[0143] In some examples, preferably, the structure of the redox polymer can be one of the following structures:

[0144]

[0145]

[0146]

[0147]

[0148] In some examples, the probe 1 may include a semipermeable membrane. The semipermeable membrane may cover at least the sensing layer 110 on the working electrode 10. In some examples, the semipermeable membrane may be a negatively charged membrane, and the negatively charged membrane may carry a negative charge. In this case, the negatively charged membrane can block some anionic interferents located outside the negatively charged membrane, thereby reducing the interference of the anionic interferents on the electrical signal generated by the redox reaction of the glucose molecule, thereby improving the anti-interference ability of the probe 1.

[0149] In some examples, anionic interferents may include ascorbic acid, uric acid, etc. In some examples, the anti-interference ability of the probe 1 to high potential interferents and anionic interferents can be improved by using the sensing layer 110 containing a low potential redox polymer on the semipermeable membrane and the working electrode 10 .

[0150] In some examples, the probe 1 may include a counter electrode. In some examples, the probe 1 may generate a current signal by performing an oxidation-reduction reaction between the glucose enzyme in the working electrode 10 and the glucose in the host body fluid and forming a loop with the counter electrode.

[0151] In some examples, the probe 1 may include a reference electrode. In some examples, the reference electrode may form a known and fixed potential difference with the body fluid. In this case, the potential difference between the working electrode 10 and the body fluid can be measured by the potential difference formed by the reference electrode and the working electrode 10, so as to accurately grasp the voltage generated by the working electrode 10. Thus, the electronic system 2 can automatically adjust and maintain the stability of the voltage at the working electrode 10 according to the pre-set voltage value to ensure that the measured current signal can accurately reflect the glucose concentration value.

[0152] In summary, in the first aspect of the present disclosure, a redox polymer having good water solubility and low redox equilibrium potential can be provided, and the monitoring probe 1 including the redox polymer has high sensitivity and strong anti-interference ability.

[0153] As described above, the second aspect of the present disclosure relates to a method for preparing a glucose monitoring probe 1. The glucose monitoring probe 1 according to the first aspect of the present disclosure can be prepared by the preparation method according to the second aspect of the present disclosure.

[0154] Figure 5 is a flow chart showing a method for preparing the glucose monitoring probe 1 according to an example of the present disclosure.

[0155] In some examples, the preparation method may include the following steps: preparing a first polymer (step S100); grafting a metal complex X onto the first polymer to obtain a redox polymer (step S200); preparing a sensing layer solution including a redox polymer (step S300); drop-coating the sensing layer solution onto the surface of the working electrode 10 to form a sensing layer 110, and obtaining a glucose monitoring probe 1 (step S400). Thus, a glucose monitoring probe 1 including a redox polymer can be prepared.

[0156] In the preparation method involved in the second aspect of the present disclosure, the redox polymer is consistent with the redox polymer in the glucose monitoring probe 1 of the first aspect of the present disclosure. For the redox polymer and the settings of its various components and parameters, please refer to the above description and will not be repeated here.

[0157] In some examples, in step S100, the first polymer may be a polymer containing a positively charged group and / or a hydrophilic group. In this case, the main chain of the subsequently synthesized redox polymer may also carry a positively charged group and / or a hydrophilic group. The positively charged group may make the surface of the redox polymer positively charged, and the surface of the redox polymer may have a stronger electrostatic interaction with the negatively charged glucose enzyme, thereby improving the efficiency of electron transfer and further improving the sensitivity of the probe 1; the hydrophilic group may improve the water solubility of the redox polymer as a whole, which is beneficial to the drop coating process.

[0158] In some examples, in step S100, the first polymer may be generated by reacting the nitrogen-containing heterocyclic compound and the first monomer. Specifically, the nitrogen-containing heterocyclic compound, the first monomer, and the free radical initiator may be mixed and dissolved in an organic solvent to react and generate the first polymer.

[0159] In some examples, in step S100, the first polymer may have a chemical structure as shown in formula (7):

[0160]

[0161] Wherein, A1 and A2 may be nitrogen-containing heterocyclic compounds, and A3 may be the first monomer.

[0162] The formula (7) involved in the second aspect of the present disclosure is consistent with the content disclosed in the formula (7) involved in the first aspect of the present disclosure, and will not be repeated here.

[0163] In some examples, in step S100, the free radical initiator can be selected from any one of ammonium persulfate, hydrogen peroxide, benzoyl peroxide, tert-butyl ketone peroxide, 2,2'-diisopropyl di(phenyl)peroxide (AIBN) or ferric chloride, thereby initiating and promoting the chemical reaction.

[0164] In some examples, in step S100, the organic solvent may be selected from any one of toluene, dimethyl sulfoxide (DMSO), acetone, chloroform, acetonitrile or N,N-dimethylformamide (DMF), thereby promoting the dissolution of reactants in the chemical reaction and the progress of the chemical reaction.

[0165] In some examples, in step S100, the first monomer may be a quaternary ammonium salt compound or a zwitterionic compound. In this case, a first polymer containing a hydrophilic group can be synthesized, the water solubility of the first polymer as a whole can be improved, and the surface of the first polymer can be positively charged.

[0166] In some examples, in step S100, the quaternary ammonium salt compound can be any one of methacrylate quaternary ammonium salt, alkyl trimethyl quaternary ammonium salt, hexadecyl trimethyl quaternary ammonium salt and dialkyl quaternary ammonium salt. Thus, a first polymer containing quaternary ammonium cations can be synthesized, so that the surface of the first polymer is positively charged, and the water solubility of the first polymer as a whole can be improved.

[0167] In some examples, in step S100, the zwitterionic compound may be any one of sulfonate betaine, carboxylate betaine and 2-methacryloyloxyethyl phosphorylcholine. Thus, a first polymer containing a hydrophilic group can be synthesized. In some examples, the hydrophilic group may be any one of a quaternary ammonium group, a sulfonic acid group and a carboxylic acid group.

[0168] In some examples, in step S100, the nitrogen-containing heterocyclic compound can be selected from any one of pyridine derivatives and imidazole derivatives. In some examples, in step S100, the nitrogen-containing heterocyclic compound can be selected from any one of 4-vinylpyridine, 2-vinylpyridine and N-vinylimidazole.

[0169] In some examples, in step S200 , the metal complex X may be grafted to the first polymer to obtain a redox polymer.

[0170] In some examples, in step S200, the redox polymer may have a structure as shown in formula (1):

[0171]

[0172] The formula (1) involved in the second aspect of the present disclosure is consistent with the content disclosed in the formula (1) involved in the first aspect of the present disclosure, and will not be repeated here.

[0173] In some examples, the step of grafting the metal complex X to the first polymer may include: selecting a metal complex X with a free amino group (step S21); modifying the first polymer so that the first polymer forms a side chain including a carboxyl group (step S22); and covalently bonding the first polymer and the metal complex X via an amide bond by dehydration condensation (step S23). In this case, the connection stability between the metal complex X and the first polymer can be improved by dehydration condensation. The order of step S21 and step S22 is not specific, and step S21 can be performed first, or step S22 can be performed first, or both can be performed simultaneously.

[0174] In some examples, in step S200, the connection between the first polymer and X may have a structure as shown in formula (6):

[0175]

[0176] The formula (6) involved in the second aspect of the present disclosure is consistent with the content disclosed in the formula (6) involved in the first aspect of the present disclosure. For details, please refer to the description of formula (6) in the first aspect of the present disclosure, which will not be repeated here.

[0177] In some examples, in step S200, the first polymer and the halogenated fatty acid compound can be mixed and dissolved in an organic solvent, the reaction system can be heated to react to generate a first polymer with a carboxyl group on the side chain, and then the metal complex X and the first polymer with a carboxyl group on the side chain can be dissolved in an organic solvent containing an activator and a catalyst to generate a redox polymer.

[0178] In some examples, in step S200, the halogenated fatty acid compound can be selected from any one of 6-bromohexanoic acid, 6-chlorohexanoic acid or 6-chloroheptanoic acid. In this case, the first polymer is modified by the halogenated fatty acid compound, so that the first polymer can form a side chain including a carboxyl group.

[0179] In some examples, in step S200, the organic solvent may be selected from any one of toluene, dimethyl sulfoxide (DMSO), acetone, chloroform, or N-dimethylformamide (DMF), thereby promoting the dissolution of reactants in the chemical reaction and the progress of the chemical reaction.

[0180] In some examples, in step S200, the activator can be selected from any one of 1-[(dimethylamino)methyl]-1H-1,2,3-triazolo(4,5-b)pyridine-3-oxide hexafluorophosphate (HATU), O-(6-chloro-1-hydroxybenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HCTU), 2-succinimidyl-1,1,3,3-tetramethyluronium tetrafluoroborate (TSTU) or O-benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU).

[0181] In some examples, in step S200 , the catalyst may be selected from any one of triethylenediamine (DIBCO), diisopropylethylamine (DIPEA), or triethylamine (TEA).

[0182] In some examples, in step S200, the metal complex X may have a structure as shown in the following formula (2):

[0183] The formula (2) involved in the second aspect of the present disclosure is consistent with the content disclosed in the formula (2) involved in the first aspect of the present disclosure, and will not be repeated here.

[0184] In some examples, in step S200, M may be a transition metal. In some examples, in step S200, M may be osmium. In some examples, in step S200, L1, L2, L3, L4, L5, and L6 may be combined in pairs to form a bidentate ligand.

[0185] In some examples, two imidazole-pyridine ligands may be included in the three bidentate ligands of X. In this case, the redox polymer can have a lower redox equilibrium potential, so that the working potential required for glucose to contact and react with the sensing layer 110 on the working electrode 10 is lower, thereby effectively reducing the redox reaction of high-potential interferents and reducing the interference of high-potential interferents on the electrical signal generated by the redox reaction of glucose molecules.

[0186] In some examples, in step S200 , L1, L2, L3, L4, L5, and L6 may be selected from any one of pyridine and imidazole.

[0187] In some examples, in step S200, the metal complex X may have a structure as shown in the following formula (3):

[0188]

[0189] The formula (3) involved in the second aspect of the present disclosure is consistent with the content disclosed in the formula (3) involved in the first aspect of the present disclosure, and will not be repeated here.

[0190] In some examples, in step S200, after the metal complex X is grafted onto the first polymer, the crude product generated by the reaction can be further refined by a chloride ion exchange resin, thereby obtaining a purified redox polymer.

[0191] In some examples, a redox polymer can be prepared by steps S100 to S200 as described above. Hereinafter, an example of a synthesis method of a redox polymer is described. It should be noted that the following chemical expression is only a schematic representation of the reaction process, and does not mean that the following chemical expression is a limitation of the preparation steps S100 to S200 of the present disclosure.

[0192] The following is an example of chemical expressions of chemical reactions involved in step S100 to step S200:

[0193]

[0194] In step S100, 4-vinylpyridine and a quaternary ammonium salt compound may be mixed and dissolved in a DMSO solvent, and an AIBN reagent may be added to the solution as an initiator of a chemical reaction, and the reaction system may be reacted at 80° C. for 3 hours to generate a first polymer;

[0195] In step S200, the first polymer and 6-bromohexanoic acid can be mixed and dissolved in a DMF solvent, the reaction system can be heated, and the temperature of the reaction system can be maintained at 90° C., and a first polymer with a carboxyl group on the side chain can be generated after the reaction; the first polymer with a carboxyl group on the side chain can be dissolved in a DMF solvent, TEA reagent and HATU reagent can be added to the reaction system, and after the reaction system is stirred at room temperature for 6 hours, a metal complex X containing a free amino group is added to the reaction system, and the reaction is continued for 24 hours, and the metal complex X and the first polymer with a carboxyl group on the side chain undergo a dehydration condensation reaction to generate an amide bond; and a redox polymer can be obtained.

[0196] In some examples, as described above, in step S300, a sensing layer solution including a redox polymer may be prepared. That is, in step S300, the sensing layer solution may include a redox polymer.

[0197] In some examples, in step S300, the sensing layer solution may include glucose enzyme, wherein the glucose enzyme may be glucose oxidase or glucose dehydrogenase.

[0198] In some examples, in step S300, the sensing layer solution may include a crosslinker. Wherein, the crosslinker may be selected from any one of glutaraldehyde, polyethylene glycol diglycidyl ether (PEGDGE) and genipin. In some examples, in step S300, the sensing layer solution may include a redox polymer, a glucase and a crosslinker. In this case, the crosslinker is capable of connecting the glucase to the redox polymer. In some examples, the mass fraction of the crosslinker may be 5% to 15%. For example, the mass fraction of the crosslinker may be 5%, 8%, 10%, 12% or 15%. In some examples, the mass ratio of the redox polymer and the glucase may be 2:8 to 8:2. For example, the mass ratio of the redox polymer and the glucase may be 2:8, 3:7, 4:6, 5:5, 6:4, 7:3 or 8:2.

[0199] In some examples, in step S400, the sensing layer solution can be applied to the surface of the working electrode 10 to form the sensing layer 110, thereby obtaining the glucose monitoring probe 1. For example, the sensing layer solution can be applied to the surface of the working electrode 10 by drop coating, spin coating, dip pulling, drop coating, or spray coating. In some examples, in step S400, preferably, the sensing layer solution can be applied to the surface of the working electrode 10 by drop coating.

[0200] In some examples, in step S400, the sensing layer solution may be drop-coated on the working electrode 10 in the form of a plurality of discrete points to form the sensing layer 110. In some examples, in step S400, a plurality of discrete points constitute the sensing layer 110. In some examples, in step S400, a plurality of points with overlapping edges may also be drop-coated on the working electrode 10 to form a sensing layer 110 in which a plurality of points are connected in a line. In this case, it is convenient to set more sensing layer solutions on the working electrode 10, which can be beneficial to improve the sensitivity of the working electrode 10.

[0201] In summary, in the second aspect of the present disclosure, by utilizing the preparation method to prepare a glucose monitoring probe 1, a monitoring probe 1 with high sensitivity and strong anti-interference ability can be obtained.

[0202] The third aspect of the present disclosure provides a redox polymer. The redox polymer involved in the third aspect of the present disclosure is consistent with the redox polymer in the glucose monitoring probe 1 of the first aspect of the present disclosure. For the redox polymer and the settings of the various components and parameters therein, please refer to the above description, which will not be repeated here. The synthesis method of the redox polymer involved in the third aspect of the present disclosure is consistent with the content disclosed in the preparation method involved in the second aspect of the present disclosure, which will not be repeated here.

[0203] The redox polymer involved in the third aspect of the present disclosure has low potential and good water solubility, and can be used as an electron mediator of a sensitive unit in an electrochemical sensor. In this case, it can play an anti-interference role against high-potential interferents and is easy to process.

[0204] The glucose monitoring probe 1 provided by the present disclosure is described in detail below in conjunction with the embodiments and comparative examples, but they should not be understood as limiting the scope of protection of the present disclosure. In order to verify the anti-interference effect of the glucose monitoring probe 1 involved in the present disclosure on high-potential interferers, uric acid (potential of about 400mV) and acetaminophen (potential of about 480mV) are taken as interferers and added to the embodiments for experiments.

[0205] First, a plurality of glucose monitoring probes 1 with working electrodes 10 of the same specifications are prepared for use.

[0206] [Example]

[0207] Example 1

[0208] 1. Mix and dissolve 4-vinylpyridine, a quaternary ammonium salt compound and an AIBN reagent in a molar ratio of 90:9:1 in a DMSO solvent to react and generate a first polymer.

[0209] 2. Mix and dissolve the first polymer and 6-bromohexanoic acid in a molar ratio of 4:1 in a DMF solvent, heat the reaction system, and maintain the temperature of the reaction system at 90° C. to react and generate a first polymer with a carboxyl group on the side chain.

[0210] 3. The metal complex X containing free amino groups and the first polymer with carboxyl groups on the side chains are dissolved in a DMF solvent containing HATU reagent and TEA reagent at a molar ratio of 5:1, wherein the molar ratio of HATU to the first polymer with carboxyl groups on the side chains is 0.2, and the molar ratio of TEA to the first polymer with carboxyl groups on the side chains is 0.4. The metal complex X and the first polymer with carboxyl groups on the side chains undergo a dehydration condensation reaction to generate a redox polymer. The redox polymer has a structure shown in the following formula (8):

[0211]

[0212] 4. The redox polymer, glucose oxidase and PEGDGE reagent in a mass ratio of 6:3:1 were mixed uniformly to prepare a sensing layer solution, and the sensing layer solution was drop-coated on the surface of the working electrode, and after drying, a sensing layer was formed, thereby obtaining the glucose monitoring probe (referred to as the probe) of Example 1. The dissolution time of the redox polymer of Example 1 was less than 0.5 hours, and the sensing layer solution after uniform mixing was clear and transparent. The viscosity of the sensing layer solution after uniform mixing was 1.33 cp (centipoise), and the redox polymer of Example 1 had good water solubility.

[0213] The glucose monitoring probe of Example 1 was tested using cyclic voltammetry at a cycle rate of 50 mV / s. Figure 6 2 is a cyclic voltammetry graph showing the probe of Example 1 after 200 cycles. Figure 7 FIG. 1 is a graph showing the oxidation peak current-cycle number curve of Example 1. Figure 8 3 is a graph showing the oxidation peak current-storage days curve of the probe of Example 1. Fig. 9 3 is a graph showing the sensitivity response of the probe of Example 1 versus glucose concentration.

[0214] from Figure 6 It can be seen from the figure that as the number of cycles changes, the position, height and width of the oxidation peak of the redox polymer in Example 1 remain roughly unchanged, and the redox polymer in Example 1 has good stability. Figure 6 The oxidation peak E of the redox polymer in Example 1 can be read from ox =19mV, restore peak value E red =-67mV, redox equilibrium potential E 1 / 2=-24 mV. Compared with the high potential interferents, the redox polymer in Example 1 has a lower redox equilibrium potential.

[0215] from Figure 7 It can be seen that the attenuation rate of the oxidation peak current value of the probe in Example 1 in the phosphate (PBS) buffer solution is 5.5%. It can be seen that with the change of the number of cycles, the oxidation peak current value of Example 1 has a slight downward trend, but remains stable overall.

[0216] from Figure 8 It can be seen that the probe of Example 1 is stored in the PBS buffer solution for 30 days, and the average daily attenuation rate of the oxidation peak current value is 0.19%. It can be seen that with the increase in the number of storage days, the oxidation peak current value of Example 1 changes slightly, but generally tends to be stable.

[0217] The sensitivity test results of the probe in Example 1 under different glucose concentrations were linearly fitted, and the fitting equation obtained was y=1.2786x+0.8465, as shown in FIG. Fig. 9 As shown, the R of the fitting equation 2 >0.99, it can be seen that the sensitivity is linearly correlated with the glucose concentration. The larger the slope of the fitting equation, the higher the sensitivity of the probe. The slope of the fitting equation of Example 1 is 1.2786, indicating that the sensitivity of the probe of Example 1 is higher.

[0218] Example 2

[0219] 1. Mix and dissolve 4-vinylpyridine, a quaternary ammonium salt compound and an AIBN reagent in a molar ratio of 90:9:1 in a DMSO solvent to react and generate a first polymer.

[0220] 2. Mix and dissolve the first polymer and 6-bromohexanoic acid in a molar ratio of 4:1 in a DMF solvent, heat the reaction system, and maintain the temperature of the reaction system at 90° C. to react and generate a first polymer with a carboxyl group on the side chain.

[0221] 3. The metal complex X containing free amino groups and the first polymer with carboxyl groups on the side chains are dissolved in a DMF solvent containing HATU reagent and TEA reagent at a molar ratio of 5:1, wherein the molar ratio of HATU to the first polymer with carboxyl groups on the side chains is 0.2, and the molar ratio of TEA to the first polymer with carboxyl groups on the side chains is 0.4. The metal complex X and the first polymer with carboxyl groups on the side chains undergo a dehydration condensation reaction to generate a redox polymer. The redox polymer has a structure shown in the following formula (9):

[0222]

[0223] 4. The redox polymer, glucose oxidase and PEGDGE reagent in a mass ratio of 6:3:1 were mixed uniformly to prepare a sensing layer solution, and the sensing layer solution was drop-coated on the surface of the working electrode, and dried to form a sensing layer, thereby obtaining the glucose monitoring probe of Example 2. The dissolution time of the redox polymer of Example 2 was less than 0.5 hours, and the sensing layer solution after mixing uniformly was clear and transparent. The viscosity of the sensing layer solution after mixing uniformly was 1.36 cp (centipoise), and the redox polymer of Example 2 had good water solubility.

[0224] The glucose monitoring probe of Example 2 was tested using cyclic voltammetry at a cycle rate of 50 mV / s. Fig.10 2 is a cyclic voltammetry graph showing the probe of Example 2 after 200 cycles. Fig.11 FIG. 2 is a graph showing the oxidation peak current-cycle number curve of Example 2. Fig.12 3 is a graph showing the oxidation peak current-storage days curve of the probe of Example 2. Fig.13 3 is a graph showing the sensitivity response of the probe of Example 2 versus glucose concentration.

[0225] from Fig.10 It can be seen from the figure that as the number of cycles changes, the position, height and width of the oxidation peak of the redox polymer in Example 2 remain roughly unchanged, and the redox polymer in Example 2 has good stability. Fig.10 The oxidation peak E of the redox polymer in Example 2 can be read from ox =160mV, restore peak value E red =40mV, redox equilibrium potential E 1 / 2 =100 mV. Compared with the high potential interferent, the redox polymer in Example 2 has a lower redox equilibrium potential.

[0226] from Fig.11 It can be seen that the attenuation rate of the oxidation peak current value of the probe of Example 2 in the PBS buffer solution is 4.3%. It can be seen that with the change of the number of cycles, the oxidation peak current value of Example 2 has a slight downward trend, but remains stable overall.

[0227] from Fig.12 It can be seen that the probe of Example 2 is stored in the PBS buffer solution for 30 days, and the average daily attenuation rate of the oxidation peak current value is 0.42%. It can be seen that with the increase in the number of storage days, the oxidation peak current value of Example 2 changes slightly, but generally tends to be stable.

[0228] The sensitivity test results of the probe in Example 2 under different glucose concentrations were linearly fitted, and the fitting equation obtained was y=1.2003x+0.5496. Fig.13 As shown, the R of the fitting equation 2 >0.99, it can be seen that the sensitivity is linearly correlated with the glucose concentration. The larger the slope of the fitting equation, the higher the sensitivity of the probe. The slope of the fitting equation of Example 2 is 1.2003, indicating that the sensitivity of the probe of Example 2 is higher.

[0229] Example 3

[0230] 1. Mix and dissolve 4-vinylpyridine, a zwitterionic compound and an AIBN reagent in a molar ratio of 90:9:1 in a DMSO solvent to react and generate a first polymer.

[0231] 2. Mix and dissolve the first polymer and 6-bromohexanoic acid in a molar ratio of 4:1 in a DMF solvent, heat the reaction system, and maintain the temperature of the reaction system at 90° C. to react and generate a first polymer with a carboxyl group on the side chain.

[0232] 3. The metal complex X containing free amino groups and the first polymer with carboxyl groups on the side chains are dissolved in a DMF solvent containing HATU reagent and TEA reagent at a molar ratio of 5:1, wherein the molar ratio of HATU to the first polymer with carboxyl groups on the side chains is 0.2, and the molar ratio of TEA to the first polymer with carboxyl groups on the side chains is 0.4. The metal complex X and the first polymer with carboxyl groups on the side chains undergo a dehydration condensation reaction to generate a redox polymer. The redox polymer has a structure shown in the following formula (10):

[0233]

[0234] 4. The redox polymer, glucose oxidase and PEGDGE reagent in a mass ratio of 6:3:1 were mixed uniformly to prepare a sensing layer solution, and the sensing layer solution was drop-coated on the surface of the working electrode and dried to form a sensing layer, thereby obtaining the glucose monitoring probe of Example 3. The dissolution time of the redox polymer of Example 3 was less than 0.5 hours, and the sensing layer solution after mixing uniformly was clear and transparent. The viscosity of the sensing layer solution after mixing uniformly was 1.45 cp (centipoise), and the redox polymer of Example 3 had good water solubility.

[0235] The glucose monitoring probe of Example 3 was tested using cyclic voltammetry at a cycle rate of 50 mV / s. Fig.14 is a graph showing a cyclic voltammetry curve of the probe of Example 3. Fig.15 3 is a graph showing the sensitivity response of the probe of Example 3 versus glucose concentration.

[0236] from Fig.14It can be seen from the figure that as the number of cycles changes, the position, height and width of the oxidation peak of the redox polymer in Example 3 remain roughly unchanged, and the redox polymer in Example 3 has good stability. Fig.14 The oxidation peak E of the redox polymer in Example 3 can be read from ox =22mV, restore peak value E red =-35mV, redox equilibrium potential E 1 / 2 =-6 mV. Compared with the high potential interferents, the redox polymer in Example 3 has a lower redox equilibrium potential.

[0237] The sensitivity test results of the probe in Example 3 under different glucose concentrations were linearly fitted, and the obtained fitting equation was y=1.1072x-0.1548, as shown in FIG. Fig.15 As shown, the R of the fitting equation 2 >0.99, it can be seen that the sensitivity is linearly correlated with the glucose concentration. The larger the slope of the fitting equation, the higher the sensitivity of the probe. The slope of the fitting equation of Example 3 is 1.1072, indicating that the sensitivity of the probe of Example 3 is higher.

[0238] Example 4

[0239] 1. Mix and dissolve 4-vinylpyridine, a zwitterionic compound and an AIBN reagent in a molar ratio of 90:9:1 in a DMSO solvent to react and generate a first polymer.

[0240] 2. Mix and dissolve the first polymer and 6-bromohexanoic acid in a molar ratio of 4:1 in a DMF solvent, heat the reaction system, and maintain the temperature of the reaction system at 90° C. to react and generate a first polymer with a carboxyl group on the side chain.

[0241] 3. The metal complex X containing free amino groups and the first polymer with carboxyl groups on the side chains are dissolved in a DMF solvent containing HATU reagent and TEA reagent at a molar ratio of 5:1, wherein the molar ratio of HATU to the first polymer with carboxyl groups on the side chains is 0.2, and the molar ratio of TEA to the first polymer with carboxyl groups on the side chains is 0.4. The metal complex X and the first polymer with carboxyl groups on the side chains undergo a dehydration condensation reaction to generate a redox polymer. The redox polymer has a structure shown in the following formula (11):

[0242]

[0243] 4. The redox polymer, glucose oxidase and PEGDGE reagent in a mass ratio of 6:3:1 were mixed uniformly to prepare a sensing layer solution, and the sensing layer solution was drop-coated on the surface of the working electrode and dried to form a sensing layer, thereby obtaining the glucose monitoring probe of Example 4. The dissolution time of the redox polymer of Example 4 was less than 0.5 hours, and the sensing layer solution after mixing uniformly was clear and transparent. The viscosity of the sensing layer solution after mixing uniformly was 1.49 cp (centipoise), and the redox polymer of Example 4 had good water solubility.

[0244] The glucose monitoring probe of Example 4 was tested using cyclic voltammetry at a cycle rate of 50 mV / s. Fig.16 is a graph showing a cyclic voltammetry curve of the probe of Example 4. Fig.17 3 is a graph showing the sensitivity response of the probe of Example 4 versus glucose concentration.

[0245] from Fig.16 It can be seen from the figure that as the number of cycles changes, the position, height and width of the oxidation peak of the redox polymer in Example 4 remain roughly unchanged, and the redox polymer in Example 4 has good stability. Fig.16 The oxidation peak E of the redox polymer in Example 4 can be read from ox =22mV, restore peak value E red =-42mV, redox equilibrium potential E 1 / 2 =-10 mV. Compared with the high potential interferent, the redox polymer in Example 4 has a lower redox equilibrium potential.

[0246] The sensitivity test results of the probe in Example 4 under different glucose concentrations were linearly fitted, and the obtained fitting equation was y=1.0632x-0.0775, as shown in FIG. Fig.17 As shown, the R of the fitting equation 2 >0.99, it can be seen that the sensitivity is linearly correlated with the glucose concentration. The larger the slope of the fitting equation, the higher the sensitivity of the probe. The slope of the fitting equation of Example 4 is 1.0632, indicating that the sensitivity of the probe of Example 4 is higher.

[0247] [Comparative Example]

[0248] Comparative Example 1

[0249] Compared with Example 1, only the redox polymer in the probe is replaced from the redox polymer in Example 1 to a redox polymer having a structure shown in the following formula (12):

[0250]

[0251] A redox polymer, glucose oxidase and PEGDGE reagent in a mass ratio of 6:3:1 were mixed uniformly to prepare a sensing layer solution, and the sensing layer solution was drop-coated on the surface of the working electrode and dried to form a sensing layer, thereby obtaining a glucose monitoring probe of Comparative Example 1. The dissolution time of the redox polymer of Comparative Example 1 was 24 hours, and the viscosity of the sensing layer solution after uniform mixing was 3.55 cp (centipoise). The water solubility of the redox polymer of Comparative Example 1 was poorer than that of the redox polymer in the embodiment.

[0252] The glucose monitoring probe of Comparative Example 1 was tested using cyclic voltammetry at a cycle rate of 50 mV / s. Fig.18 is a graph showing a cyclic voltammetry curve of the probe of Comparative Example 1. Fig.19 is a graph showing the sensitivity response-glucose concentration curve of the probe of Comparative Example 1.

[0253] from Fig.18 It can be seen that the oxidation peak E of the redox polymer in Comparative Example 1 ox =210mV, restore peak value E red =116mV, redox equilibrium potential E 1 / 2 =163 mV. Compared with the examples, the redox polymer in Comparative Example 1 has a higher redox equilibrium potential.

[0254] The sensitivity test results of the probe of Comparative Example 1 under different glucose concentrations were linearly fitted, and the fitting equation obtained was y=0.4078x+0.0198, as shown in Fig.19 As shown, the R of the fitting equation 2 >0.99, it can be seen that the sensitivity is linearly correlated with the glucose concentration. The larger the slope of the fitting equation, the higher the sensitivity of the probe. The slope of the fitting equation of comparative example 1 is 0.4078, indicating that the sensitivity of the probe of comparative example 1 is lower than that of the probe of the embodiment.

[0255] Comparative Example 2

[0256] Compared with Example 1, only the redox polymer in the probe is replaced from the redox polymer in Example 1 to a redox polymer having a structure shown in the following formula (13):

[0257]

[0258] A redox polymer, glucose oxidase and PEGDGE reagent in a mass ratio of 6:3:1 were mixed uniformly to prepare a sensing layer solution, and the sensing layer solution was drop-coated on the surface of the working electrode and dried to form a sensing layer, thereby obtaining a glucose monitoring probe of Comparative Example 2. The dissolution time of the redox polymer of Comparative Example 2 was 24 hours, and the viscosity of the sensing layer solution after uniform mixing was 8.25 cp (centipoise). The water solubility of the redox polymer of Comparative Example 2 was poorer than that of the redox polymer in the embodiment.

[0259] The glucose monitoring probe of Comparative Example 2 was tested using cyclic voltammetry at a cycle rate of 50 mV / s. Fig. 20 is a graph showing a cyclic voltammetry curve of the probe of Comparative Example 2. Fig.21 3 is a graph showing the sensitivity response-glucose concentration curve of the probe of Comparative Example 2.

[0260] from Fig. 20 It can be seen that the oxidation peak E of the redox polymer in Comparative Example 2 ox =250mV, restore peak value E red =115mV, redox equilibrium potential E 1 / 2 =183 mV. Compared with the examples, the redox polymer in Comparative Example 2 has a higher redox equilibrium potential.

[0261] The sensitivity test results of the probe of Comparative Example 2 under different glucose concentrations were linearly fitted, and the fitting equation obtained was y=0.1965x+0.3203, as shown in FIG. Fig.21 As shown, the R of the fitting equation 2 >0.99, it can be seen that the sensitivity is linearly correlated with the glucose concentration. The larger the slope of the fitting equation, the higher the sensitivity of the probe. The slope of the fitting equation of Comparative Example 2 is 0.1965, indicating that the sensitivity of the probe of Comparative Example 2 is lower than that of the probe of the embodiment.

[0262] Comparative Example 3

[0263] Compared with Example 1, only the redox polymer in the probe is replaced from the redox polymer in Example 1 to a redox polymer having a structure shown in the following formula (14):

[0264]

[0265] A redox polymer, glucose oxidase and PEGDGE reagent in a mass ratio of 6:3:1 were mixed uniformly to prepare a sensing layer solution, and the sensing layer solution was drop-coated on the surface of the working electrode and dried to form a sensing layer, thereby obtaining a glucose monitoring probe of Comparative Example 3. The dissolution time of the redox polymer of Comparative Example 3 was 24 hours, and the viscosity of the sensing layer solution after uniform mixing was 9.58 cp (centipoise). The water solubility of the redox polymer of Comparative Example 3 was poorer than that of the redox polymer in the embodiment.

[0266] The glucose monitoring probe of Comparative Example 3 was tested using cyclic voltammetry at a cycle rate of 50 mV / s. Fig. 22 is a cyclic voltammetry graph showing the probe of Comparative Example 3. Fig.23 3 is a graph showing the sensitivity response-glucose concentration curve of the probe of Comparative Example 3.

[0267] from Fig. 22 It can be seen that the oxidation peak E ox =225mV, restore peak value E red =158mV, redox equilibrium potential E 1 / 2 =192 mV. Compared with the examples, the redox polymer in Comparative Example 3 has a higher redox equilibrium potential.

[0268] The sensitivity test results of the probe of Comparative Example 3 under different glucose concentrations were linearly fitted, and the fitting equation obtained was y=0.1681x+0.2542, as shown in Fig.23 As shown, the R of the fitting equation 2 >0.99, it can be seen that the sensitivity is linearly correlated with the glucose concentration. The larger the slope of the fitting equation, the higher the sensitivity of the probe. The slope of the fitting equation of comparative example 3 is 0.1681, indicating that the sensitivity of the probe of comparative example 3 is lower than that of the probe of the embodiment.

[0269] The anti-interference ability of the probes of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 for uric acid and acetaminophen was tested, as follows:

[0270] 1. The probe of Example 1 was immersed in PBS buffer solutions containing glucose concentrations of 5 mmol / L (millimoles per liter) and 15 mmol / L, and the measured current value was recorded as reading 1. The results are shown in Table 1.

[0271] 2. The probe of Example 1 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and uric acid concentration of 23.5 mg / dL (milligrams per deciliter), and the measured current value was recorded as reading 2. The results are shown in Table 1.

[0272] 3. The probe of Example 1 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and acetaminophen concentration of 20 mg / dL, and the measured current value was recorded as reading 3. The results are shown in Table 1.

[0273] 4. The probe of Example 2 was immersed in PBS buffer solutions containing glucose concentrations of 5 mmol / L (millimoles per liter) and 15 mmol / L, and the measured current value was recorded as reading 4. The results are shown in Table 2.

[0274] 5. The probe of Example 2 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and uric acid concentration of 23.5 mg / dL (milligrams per deciliter), and the measured current value was recorded as reading 5. The results are shown in Table 2.

[0275] 6. The probe of Example 2 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and acetaminophen concentration of 20 mg / dL, and the measured current value was recorded as reading 6. The results are shown in Table 2.

[0276] 7. The probe of Comparative Example 1 was immersed in PBS buffer solutions containing glucose concentrations of 5 mmol / L and 15 mmol / L, and the measured current value was recorded as reading 7. The results are shown in Table 3.

[0277] 8. The probe of comparative example 1 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and uric acid concentration of 23.5 mg / dL, and the measured current value was recorded as reading 8. The results are shown in Table 3.

[0278] 9. The probe of comparative example 1 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and acetaminophen concentration of 20 mg / dL, and the measured current value was recorded as reading 9. The results are shown in Table 3.

[0279] 10. The probe of Comparative Example 2 was immersed in PBS buffer solutions containing glucose concentrations of 5 mmol / L and 15 mmol / L, and the measured current value was recorded as reading 10. The results are shown in Table 4.

[0280] 11. The probe of comparative example 2 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and uric acid concentration of 23.5 mg / dL, and the measured current value was recorded as reading 11. The results are shown in Table 4.

[0281] 12. The probe of Comparative Example 2 was immersed in a PBS buffer solution containing glucose concentrations of 5 mmol / L and 15 mmol / L and acetaminophen concentration of 20 mg / dL, and the measured current value was recorded as reading 12. The results are shown in Table 4.

[0282] Table 1 below shows the experimental data of the test of the anti-interference ability of the probe of Example 1 for uric acid and acetaminophen:

[0283] Table 1

[0284]

[0285] In Table 1, the current change rate 1 is expressed as the change rate of reading 2 relative to reading 1, and its calculation formula is current change rate 1 = (reading 2-reading 1) / reading 1*100%, which can show the anti-interference ability of the probe of Example 1 to uric acid; the current change rate 2 is expressed as the change rate of reading 3 relative to reading 1, and its calculation formula is current change rate 2 = (reading 3-reading 1) / reading 1*100%, which can show the anti-interference ability of the probe of Example 1 to acetaminophen. The larger the absolute value of the current change rate, the weaker the anti-interference ability of the probe.

[0286] It can be seen from Table 1 that when the probe of Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 0.27%; when the probe of Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 0.05%.

[0287] It can be seen from Table 1 that when the probe of Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is -0.68%; when the probe of Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is -0.36%.

[0288] Table 2 below shows the experimental data of the test of the anti-interference ability of the probe of Example 2 for uric acid and acetaminophen:

[0289] Table 2

[0290]

[0291] In Table 2, the current change rate 3 is expressed as the change rate of reading 5 relative to reading 4, and its calculation formula is current change rate 3 = (reading 5-reading 4) / reading 4*100%, which can show the anti-interference ability of the probe of Example 2 to uric acid; the current change rate 4 is expressed as the change rate of reading 6 relative to reading 4, and its calculation formula is current change rate 4 = (reading 6-reading 4) / reading 4*100%, which can show the anti-interference ability of the probe of Example 2 to acetaminophen. The larger the absolute value of the current change rate, the weaker the anti-interference ability of the probe.

[0292] It can be seen from Table 2 that when the probe of Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 4.20%; when the probe of Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 2.56%.

[0293] It can be seen from Table 2 that when the probe of Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is 10.73%; when the probe of Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is 4.62%.

[0294] Table 3 below shows the experimental data of the test of the anti-interference ability of the probe of Comparative Example 1 for uric acid and acetaminophen:

[0295] Table 3

[0296]

[0297] In Table 3, the current change rate 5 is expressed as the change rate of reading 8 relative to reading 7, and its calculation formula is current change rate 5 = (reading 8-reading 7) / reading 7*100%, which can show the anti-interference ability of the probe of Comparative Example 1 to uric acid; the current change rate 6 is expressed as the change rate of reading 9 relative to reading 7, and its calculation formula is current change rate 6 = (reading 9-reading 7) / reading 7*100%, which can show the anti-interference ability of the probe of Comparative Example 1 to acetaminophen. The larger the absolute value of the current change rate, the weaker the anti-interference ability of the probe.

[0298] It can be seen from Table 3 that when the probe of Comparative Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 12.08%; when the probe of Comparative Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 6.97%.

[0299] It can be seen from Table 3 that when the probe of Comparative Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is 52.17%; when the probe of Comparative Example 1 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is 19.73%.

[0300] Table 4 below shows the experimental data of the test of the anti-interference ability of the probe of Comparative Example 2 for uric acid and acetaminophen:

[0301] Table 4

[0302]

[0303] In Table 4, the current change rate 7 is expressed as the change rate of reading 11 relative to reading 10, and its calculation formula is current change rate 7 = (reading 11-reading 10) / reading 10*100%, which can show the anti-interference ability of the probe of Comparative Example 2 to uric acid; the current change rate 8 is expressed as the change rate of reading 12 relative to reading 10, and its calculation formula is current change rate 8 = (reading 12-reading 10) / reading 10*100%, which can show the anti-interference ability of the probe of Comparative Example 2 to acetaminophen. The larger the absolute value of the current change rate, the weaker the anti-interference ability of the probe.

[0304] It can be seen from Table 4 that when the probe of Comparative Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 12.31%; when the probe of Comparative Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and a uric acid concentration of 23.5 mg / dL, the current change rate is 6.10%.

[0305] It can be seen from Table 4 that when the probe of Comparative Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 5 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is 75.38%; when the probe of Comparative Example 2 is immersed in a PBS buffer solution containing a glucose concentration of 15 mmol / L and an acetaminophen concentration of 20 mg / dL, the current change rate is 31.71%.

[0306] Therefore, it can be seen that when the probes of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 are in the same solution system, the absolute value of the current change rate of the probes of Comparative Example 1 and Comparative Example 2 is greater than the absolute value of the current change rate of the probes of Example 1 and Example 2. In other words, the anti-interference ability of the probes of Example 1 and Example 2 to uric acid and acetaminophen is better than the anti-interference ability of the probes of Comparative Example 1 and Comparative Example 2 to uric acid and acetaminophen. The reason is that the redox polymer with lower redox equilibrium potential can reduce the redox reaction of high potential interfering substances (uric acid and acetaminophen, etc.), and then can reduce the interference of the electrical signal produced by the redox reaction of glucose molecules by high potential interfering substances (uric acid and acetaminophen, etc.).

[0307] In summary, the sensitivity of the probes of Examples 1 to 4 is linearly correlated with the glucose concentration, indicating that the probes provided by the present disclosure have good sensitivity. In addition, the working potential required for the probes of Examples 1 to 4 is relatively low, and glucose can be brought into contact with the sensing layer on the working electrode to react between -100mV and 100mV, which can reduce the interference of high-potential interferents with the electrical signals generated by the redox reaction of glucose molecules. Therefore, the present disclosure can provide a glucose monitoring probe with high sensitivity and strong anti-interference ability.

[0308] Although the present disclosure is specifically described above in conjunction with the accompanying drawings and examples, it is to be understood that the above description does not limit the present disclosure in any form. Those skilled in the art may modify and change the present disclosure as needed without departing from the essential spirit and scope of the present disclosure, and these modifications and changes all fall within the scope of the present disclosure.

Claims

1. A glucose monitoring probe, characterized in that: The glucose monitoring probe comprises a working electrode, on which a sensing layer is arranged, wherein the sensing layer comprises glucose enzyme and a redox polymer. The redox polymer has a structure as shown in the following formula (1): in, A1 and A2 are the same and are selected from any one of 4-vinylpyridine and N-vinylimidazole, A3 is a quaternary ammonium salt of methacrylate, X has the structure shown in the following formula (2): in, M is osmium, L1, L2, L3, L4, L5 and L6 are nitrogen-containing heterocyclic ligands, and are combined in pairs to form three bidentate ligands, and the three bidentate ligands include at least two imidazole-pyridine ligands; n1, n2 and n3 are the same or different and are any natural number between 100 and 1000.

2. The glucose monitoring probe according to claim 1, characterized in that: X has the structure shown in the following formula (3): Wherein, Y is a halogen ion, and n4 is any natural number from 2 to 5.

3. The glucose monitoring probe according to claim 1, characterized in that: X has the structure shown in the following formula (4): Wherein, R1, R2, R3, R4, R5 and R6 are the same or different and are independently selected from hydrogen, methyl, methoxy, trifluoromethyl or amino.

4. The glucose monitoring probe according to claim 1, characterized in that: X has the structure shown in the following formula (5): Among them, R7, R8, R9, R 10 , R 11 , R 12 and R 13 are the same or different and are each independently selected from hydrogen, methyl, methoxy, trifluoromethyl or amino.

5. The glucose monitoring probe according to claim 1, characterized in that: A2 and X are covalently bonded via an amide bond by dehydration condensation, and the connection between A2 and X has a structure shown in formula (6): Wherein, n5 is the number of hydrocarbon chains between the amide bond and A2, and is any natural number from 1 to 10; n6 is the number of hydrocarbon chains between the amide bond and X, and is any natural number from 1 to 10.

6. The glucose monitoring probe according to claim 1, characterized in that: L1, L2, L3, L4, L5 and L6 are independently selected from any one of pyridine, imidazole, pyrimidine, thiazole and pyrrole.

7. The glucose monitoring probe according to claim 1, characterized in that: The structure of the redox polymer is one of the following structures:

8. A method for preparing a glucose monitoring probe, the glucose monitoring probe comprising a working electrode, characterized in that: The preparation method comprises: Reacting a nitrogen-containing heterocyclic compound with a quaternary ammonium salt of a methacrylate to generate a first polymer containing a quaternary ammonium salt, wherein the nitrogen-containing heterocyclic compound is selected from any one of 4-vinylpyridine and N-vinylimidazole; The metal complex X is grafted onto the first polymer to obtain a redox polymer as shown in the following formula (1): wherein A1 and A2 are the same and are selected from any one of 4-vinylpyridine and N-vinylimidazole, A3 is a quaternary ammonium salt of methacrylate, The metal complex X has a structure as shown in the following formula (2): in, M is osmium, L1, L2, L3, L4, L5 and L6 are nitrogen-containing heterocyclic ligands, and are combined in pairs to form three bidentate ligands, and the three bidentate ligands include at least two imidazole-pyridine ligands, and n1, n2 and n3 are the same or different and are any natural number from 100 to 1000; preparing a sensing layer solution including the redox polymer, glucose enzyme and a cross-linking agent; The sensing layer solution is drop-coated on the surface of the working electrode to form a sensing layer, thereby obtaining a glucose monitoring probe including the redox polymer.

9. The preparation method according to claim 8, characterized in that: The step of grafting the metal complex X to the first polymer comprises: Selecting the metal complex X with a free amino group; Modifying the first polymer so that the first polymer forms a side chain including a carboxyl group; The first polymer and the metal complex X are covalently bonded via an amide bond by dehydration condensation, and the connection between the first polymer and X has a structure shown in formula (6): Wherein, n5 is the number of hydrocarbon chains between the amide bond and A2, and is any natural number from 1 to 10; n6 is the number of hydrocarbon chains between the amide bond and X, and is any natural number from 1 to 10.

10. The preparation method according to claim 8, characterized in that: The metal complex X has a structure as shown in the following formula (3): Wherein, Y is a halogen ion, and n4 is any natural number from 2 to 5.

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