A Co-based catalytic material for glucose sensing, its preparation method and application

Abstract

This invention belongs to the field of biocatalytic material sensing technology, specifically relating to a Co-based catalytic material for glucose sensing, its preparation method, and its application. A Co-based precursor containing modified groups is impregnated with a nanodiamond support in an organic solvent, followed by high-temperature calcination under an inert atmosphere to obtain a Co-based catalytic material with highly dispersed Co-N4 enzyme-like sites. The formation of Co-N4 solves the problems of easy metal detachment, instability, and agglomeration in traditional single-atom catalytic materials. The electron cloud density of the Co-N4 active center is precisely controlled through the electronic effect of the group, significantly improving the enzyme-like catalytic performance. The Co-based catalytic material prepared by this invention can be coupled with glucose oxidase to construct an enzyme-enzyme system, solving the problems of easy inactivation and poor anti-interference of traditional enzymes while retaining the high specificity of glucose oxidase, achieving high glucose sensing performance.

Description

Technical Field

[0001] This invention belongs to the field of biocatalytic material sensing technology, specifically relating to a Co-based catalytic material for glucose sensing, its preparation method, and its application. Background Technology

[0002] Enzyme-based glucose biosensors constructed using glucose oxidase and glucose dehydrogenase have long dominated the mainstream commercial market due to their excellent specificity and sensitivity. However, these sensors have significant drawbacks: the enzymes have poor heat and chemical corrosion resistance, are easily affected by external environmental interference, and also suffer from high manufacturing costs and short lifespans.

[0003] The rise of nanotechnology has provided a new approach to overcoming the limitations of natural enzymes in biosensing. The enzyme-like activity of nanocatalysts has been gradually discovered and applied to the field of biosensing, achieving a cross-disciplinary breakthrough from "bioenzyme sensing" to "enzyme-mimicking sensing." Among these, cobalt-based materials possess abundant valence states (Co... 2+ / Co 3+ It exhibits excellent catalytic performance in glucose oxidation and H2O2 decomposition reactions. Its electronic structure is highly similar to that of natural peroxidase, making it an ideal enzyme-mimicking catalytic center.

[0004] Existing Co-based materials have some shortcomings in glucose detection: metal agglomeration in Co-based materials seriously affects catalytic stability; the electrodes of enzyme-like electrochemical systems are prone to oxidation, generating strong interference signals; the electronic structure regulation space is limited, and the catalytic performance of enzyme-like materials is not fully utilized; the anti-interference ability and linear range of glucose sensing are insufficient, which cannot meet the performance requirements of practical detection applications.

[0005] Therefore, there is an urgent need for a Co-based material suitable for glucose detection to solve the problems of easy aggregation, easy shedding of Co atoms, instability, insufficient utilization of enzyme-like activity, and insufficient catalytic performance of Co-based materials. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a Co-based catalytic material for glucose sensing, its preparation method, and its application. The prepared Co-based single-atom catalytic material involves impregnating a cobalt-based precursor containing modifying groups (amino, carboxyl, and chloro groups) with a nanodiamond support in an organic solvent, followed by high-temperature calcination under an inert atmosphere. This process causes the precursor groups to generate covalent or strong electrostatic interactions on the nanodiamond surface, ensuring that Co atoms are anchored in situ during pyrolysis, effectively inhibiting migration and aggregation. This results in a Co-based single-atom catalytic material with Co-N4 enzyme-like sites. The highly dispersed Co-N4 sites address the problem of easy aggregation in existing Co-based catalytic materials. The problem of easy atom shedding and instability is addressed by precisely controlling the electron density distribution around the Co-N4 active center through the electronic effects of functional groups (amino, carboxyl, and chlorine groups), significantly improving enzyme-like catalytic performance. Co-based catalytic materials are coupled with glucose oxidase to construct an enzyme-enzyme cascade reaction system for glucose sensing. The electronic structure and coordination environment of the Co-N4 site are highly similar to those of natural peroxidases (such as Fe-N4 of heme iron), giving it specific recognition and efficient activation capabilities for hydrogen peroxide produced from glucose oxidase. This allows it to efficiently and specifically catalyze the intermediate product H2O2 in the cascade reaction, while remaining inert to interfering substances coexisting in the reaction solution. This results in high sensitivity, low detection limit, wide linear range, good selectivity, and high anti-interference ability.

[0007] Specifically, the present invention provides a Co-based catalytic material for glucose sensing, wherein the Co-based catalytic material has highly dispersed Co-N4 enzyme-mimicking sites, which are highly similar to the electronic structure and coordination microenvironment of natural peroxidase.

[0008] Preferably, the surface of the Co-based catalytic material has different modifying groups, which are one of amino, carboxyl, or chlorine groups, used to adjust the catalytic activity of the Co-based catalytic material.

[0009] The second aspect of the present invention provides a method for preparing a Co-based catalytic material for glucose sensing. The preparation method includes reacting a Co-containing precursor with a nanodiamond support in a solvent using an equal-volume impregnation method, drying the mixture, and then calcining it in a tube furnace under an inert gas atmosphere to obtain the Co-based catalytic material.

[0010] Preferably, the Co-containing precursor is one of tetraaminocobalt phthalocyanine, tetracarboxycobalt phthalocyanine, and perchlorocobalt phthalocyanine.

[0011] Preferably, the Co-containing precursor has a Co loading of 0.5%.

[0012] Preferably, the solvent is one of N,N-dimethylformamide, dimethyl sulfoxide, ethyl acetate, acetonitrile, isopropanol, and n-hexane.

[0013] Preferably, the drying temperature is 60℃-100℃, the inert atmosphere is argon or nitrogen, the calcination temperature is 300℃-600℃, and the calcination time is 1 h-2 h.

[0014] The third aspect of this invention provides an application of a Co-based catalytic material in the preparation of a glucose sensor, wherein the Co-based catalytic material is coupled with a glucose oxidase cascade to construct an enzyme-enzyme composite sensing system for glucose detection.

[0015] Preferably, in the process of glucose detection by the enzyme-enzyme composite sensing system, glucose is first oxidized to hydrogen peroxide by glucose oxidase, and then hydrogen peroxide is oxidized by the Co-N4 enzyme-like site of the Co-based catalytic material, thereby achieving quantitative detection of glucose.

[0016] Preferably, the linear detection range of the glucose concentration is 0.1-1.0 mM.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The Co-based catalytic material prepared in this invention generates highly dispersed Co-N4 enzyme-like sites, which solves the problem of easy aggregation and easy shedding of Co elements. The highly dispersed structural features fully expose the active sites, greatly improve the catalytic efficiency, and achieve high sensitivity and high stability of the glucose sensing system. Different groups can be modified on the surface of the Co-based catalytic material, which affects the electron density distribution around Co. The catalytic activity of the Co-based catalytic material can be adjusted by modifying the groups.

[0018] (2) The Co-N4 enzyme-mimicking site generated by the present invention has an electronic structure and coordination microenvironment that are highly similar to those of natural peroxidase. It has specific recognition and high-efficiency activation ability for hydrogen peroxide produced by glucose oxidase. It only produces a significant catalytic response to H2O2, an intermediate product of the cascade reaction, while exhibiting inertness to common interfering substances such as urea and ascorbic acid. This endows the sensing system with excellent anti-interference ability and high selectivity.

[0019] (3) This invention couples Co-based catalytic materials with glucose oxidase in a cascade to construct an enzyme-enzyme composite sensing system. Glucose oxidase acts as a primary catalyst, specifically catalyzing the production of H2O2 from glucose; Co-N4 acts as a secondary enzyme-mimicking catalyst, specifically catalyzing the production of reactive oxygen species from H2O2. The reactive oxygen species react with TMB to produce a colorimetric reaction, and the glucose content can be quantitatively detected by measuring the absorbance at 652 nm. Both catalysts have substrate specificity, avoiding interference from other substances in complex samples. They have the advantages of high sensitivity, wide linear range, high anti-interference ability, and strong glucose detection specificity. This solves the problems of easy inactivation and poor anti-interference of traditional enzymes, while retaining the high specificity of glucose oxidase. It can be used for rapid, convenient, and simple glucose detection, and has good application value in diabetes prevention, food testing, and the pharmaceutical industry. Attached Figure Description

[0020] Figure 1 These are SEM images of Examples 1-3 of the present invention, wherein (a) is the SEM image of the Co-based catalytic material of Example 1, (b) is the SEM image of the Co-based catalytic material of Example 2, and (c) is the SEM image of the Co-based catalytic material of Example 3.

[0021] Figure 2 The HAADF-STEM and EDS-Mapping diagrams of Examples 1-3 of the present invention are shown below. (a) is the HAADF-STEM and EDS-Mapping diagram of Example 1 of the present invention, (b) is the HAADF-STEM and EDS-Mapping diagram of Example 2 of the present invention, and (c) is the HAADF-STEM and EDS-Mapping diagram of Example 3 prepared in accordance with the present invention.

[0022] Figure 3 These are XRD patterns of the Co-based catalytic materials prepared in Examples 1-3 of this invention.

[0023] Figure 4 This is the BET diagram of the Co-based catalytic materials prepared in Examples 1-3 of this invention.

[0024] Figure 5 These are XPS spectra of the Co-based catalytic materials prepared in Examples 1-3 of this invention.

[0025] Figure 6 These are the peroxidase-like activity reaction kinetics results of the Co-based catalytic materials prepared in Examples 1-3 of this invention.

[0026] Figure 7 These are the optimal conditions screening results of Embodiment 1 of the present invention, where (a) is the TMB concentration, (b) is the H2O2 concentration, and (c) is the pH value.

[0027] Figure 8 These are the glucose sensing results of Example 1 of the present invention, where (a) represents glucose sensing performance, (b) represents glucose selectivity, and (c) represents the system's anti-interference capability. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are also within the scope of protection of this disclosure.

[0029] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the specification and in the relevant art, and shall not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein.

[0030] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] Unless otherwise specified, all raw materials used in this invention are commercially available products well known in the art.

[0032] The present invention provides a method for preparing a Co-based catalytic material for glucose sensing, specifically comprising: reacting a Co-containing precursor with a nanodiamond support by an equal-volume impregnation method in a solvent, drying, and then calcining in a tube furnace under an inert gas atmosphere to obtain the Co-based catalytic material.

[0033] In some embodiments of the present invention, during the preparation of Co-based catalytic materials, one of tetraaminocobalt phthalocyanine, tetracarboxycobalt phthalocyanine, and perchlorocobalt phthalocyanine is used as a precursor (preferably with a Co element loading of 0.5%), and reacted with DND R nanodiamond support in a solvent. The solvent is preferably one of N,N-dimethylformamide (DMF), dimethyl sulfoxide, ethyl acetate, acetonitrile, isopropanol, and n-hexane, more preferably N,N-dimethylformamide (DMF). The reaction is carried out by impregnation, specifically by equal-volume impregnation. The amount of DMF is positively correlated with the pore volume, water absorption rate, and specific surface area of ​​the support. During impregnation, the mixture of precursor, support, and solvent is ultrasonically treated for 2 min and stirred, then allowed to stand for 10 min, repeated more than ten times. The mixture is then placed in a water bath at 55 °C to accelerate solvent evaporation, and stirred at 30 min intervals. The mixture with drying cracks is placed in an oven at a drying temperature of 60 °C-100 °C (preferably 60 °C) for 10 minutes. h, and then calcined in an inert gas (argon or nitrogen) atmosphere in a tube furnace, preferably at a calcination temperature of 300℃-600℃ (more preferably 400℃), and preferably for 1h-2h (more preferably 1h).

[0034] In some embodiments of the present invention, the strategy adopted for preparing Co-based catalytic materials is as follows: a directional, molecular-level synergistic system is formed between a cobalt phthalocyanine precursor containing amino, carboxyl, or chlorine groups and a nanodiamond support with a surface rich in functional groups. The precursor groups and the nanodiamond surface are connected by covalent or strong electrostatic interactions, which ensures that Co atoms are anchored in situ during pyrolysis, effectively inhibiting migration and aggregation, and ultimately forming highly dispersed Co-N4 sites.

[0035] The present invention also provides the application of Co-based catalytic materials in the preparation of glucose sensors. The Co-based catalytic materials are coupled with glucose oxidase in a cascade to construct an enzyme-enzyme composite sensing system for glucose detection. First, glucose is oxidized to H2O2 by glucose oxidase, and then H2O2 is oxidized by the Co-N4 enzyme-like site of the Co-based catalytic material, thereby realizing the quantitative detection of glucose.

[0036] In some embodiments of the present invention, the electronic structure and coordination environment of the Co-N4 enzyme-mimicking site are highly similar to those of natural peroxidases (such as Fe-N4 of heme iron), exhibiting specific recognition and efficient activation capabilities for hydrogen peroxide produced from glucose oxidase catalyzed by glucose oxidase. This enables it to efficiently and specifically catalyze the intermediate product H2O2 in the cascade reaction, while remaining inert to other interfering substances coexisting in the reaction solution. Quantitative detection of glucose is achieved by constructing an enzyme-enzyme composite sensing system through the cascade coupling of Co-based catalytic materials and glucose oxidase. Glucose oxidase acts as the primary catalyst, specifically catalyzing the production of H2O2 from glucose; Co-N4 acts as the secondary enzyme-mimicking catalyst, specifically catalyzing H2O2, thus avoiding interference from other substances in complex samples and achieving excellent selectivity.

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments: Example

[0038] The preparation of a Co-based catalytic material and its application in glucose sensing are as follows: (1) Preparation of Co-based catalytic material: Tetraaminophthalocyanine cobalt modified with electron-donating ability was selected as the precursor, DMF was selected as the solvent, and nanodiamond was selected as the support. All materials were placed in a small beaker, sonicated and heated to accelerate solvent evaporation. After drying, the materials were placed in an oven to continue drying for 10 h. Then the materials were ground into fine powder and calcined in a tube furnace at 400℃ with Ar introduced for 1 h. The heating rate was 5℃ per minute. Finally, the Co-based catalytic material CoPc-NH2 / ND was obtained.

[0039] (2) Peroxidase-like activity was tested using the TMB probe reaction: 180 mg of 3,3',5,5'-tetramethylbenzidine (TMB) was dissolved in 1 mL of dimethyl sulfoxide (DMSO) and wrapped in aluminum foil for storage in the dark. 1.64 g of sodium acetate was dissolved in 20 mL of water to obtain a sodium acetate stock solution. 11.8 mL of acetic acid was added to a final volume of 200 mL to obtain an acetic acid stock solution. 15 mL of the sodium acetate stock solution was mixed with 185 mL of the acetic acid stock solution to obtain an acetate-sodium acetate buffer solution with a pH of 3.6. The nanodrop (instrument for measuring absorbance) was heated to 37 °C. 965 μL of buffer solution and 5 μL of catalyst were added to a cuvette with a 1 cm optical path length, respectively, as a blank control. Then, 10 μL of TMB and 20 μL of H2O2 were added. The absorbance curve of the system at 400 s was tested, and the catalytic performance of the catalyst was judged by the curve trend.

[0040] (3) Prepare glucose solutions of different concentrations. First, prepare a 10 mmol / L glucose stock solution. Weigh 1.8 g of glucose and dissolve it in 1 L of acetate-sodium acetate buffer solution, which is called solution 1. After shaking, take 500 mL of solution 1 and mix it with 500 mL of acetate-sodium acetate buffer solution to obtain a 5 mmol / L glucose solution, which is called solution 2. And so on, to obtain a series of glucose solutions with concentrations of 10 mM, 5 mM, 2.5 mM, 1 mM, 0.5 mM, 0.25 mM and 0.1 mM. Weigh 10 mg of glucose oxidase and dissolve it in 10 mL of acetate-sodium acetate buffer solution to obtain a 1 mg / mL glucose oxidase solution. Wrap it in aluminum foil and store it at low temperature. Take 120 μL of glucose solution of different concentrations and add 20 μL of glucose oxidase solution. Incubate in a microplate reader at 37 °C for 1 h. Add the incubated mixed solution to a 96-well plate, and add 30 μL of CoPc-NH2 / ND and 30 μL of LTMB. Shake for 10 min and test its absorbance at 652 nm. Example

[0041] The preparation of a Co-based catalytic material and its application in glucose sensing are as follows: (1) Preparation of Co-based catalytic material: Tetracarboxylated cobalt phthalocyanine modified with electron-withdrawing ability was selected as the precursor, DMF was selected as the solvent, and nanodiamond was selected as the carrier. All materials were placed in a small beaker, sonicated and heated to accelerate solvent evaporation. After drying, the materials were placed in an oven to continue drying for 10 h. Then the materials were ground into fine powder and calcined in a tube furnace at 400℃ with Ar introduced for 1 h. The heating rate was 5℃ per minute. Finally, the Co-based catalytic material CoPc-COOH / ND was obtained.

[0042] (2) Peroxidase-like activity was tested using the TMB probe reaction: 180 mg of 3,3',5,5'-tetramethylbenzidine (TMB) was dissolved in 1 mL of dimethyl sulfoxide (DMSO) and wrapped in aluminum foil for storage in the dark. 1.64 g of sodium acetate was dissolved in 20 mL of water to obtain a sodium acetate stock solution. 11.8 mL of acetic acid was added to a final volume of 200 mL to obtain an acetic acid stock solution. 15 mL of the sodium acetate stock solution was mixed with 185 mL of the acetic acid stock solution to obtain an acetate-sodium acetate buffer solution with a pH of 3.6. The nanodrop (instrument for measuring absorbance) was heated to 37 °C. 965 μL of buffer solution and 5 μL of catalyst were added to a cuvette with a 1 cm optical path length, respectively, as a blank control. Then, 10 μL of TMB and 20 μL of H2O2 were added. The absorbance curve of the system at 400 s was tested, and the catalytic performance of the catalyst was judged by the curve trend.

[0043] (3) Prepare glucose solutions of different concentrations. First, prepare a 10 mmol / L glucose stock solution. Weigh 1.8 g of glucose and dissolve it in 1 L of acetate-sodium acetate buffer solution, which is called solution 1. After shaking, take 500 mL of solution 1 and mix it with 500 mL of acetate-sodium acetate buffer solution to obtain a 5 mmol / L glucose solution, which is called solution 2. And so on, to obtain a series of glucose solutions with concentrations of 10 mM, 5 mM, 2.5 mM, 1 mM, 0.5 mM, 0.25 mM and 0.1 mM. Weigh 10 mg of glucose oxidase and dissolve it in 10 mL of acetate-sodium acetate buffer solution to obtain a 1 mg / mL glucose oxidase solution. Wrap it in aluminum foil and store it at low temperature. Take 120 μL of glucose solution of different concentrations and add 20 μL of glucose oxidase solution. Incubate in a microplate reader at 37 °C for 1 h. Add the incubated mixed solution to a 96-well plate, and add 30 μL of CoPc-COOH / ND and 30 μL of LTMB. Shake for 10 min and test its absorbance at 652 nm. Example

[0044] The preparation of a Co-based catalytic material and its application in glucose sensing are as follows: (1) Preparation of Co-based catalytic material: Cobalt phthalocyanine modified with electron-withdrawing ability (-Cl) was selected as the precursor, DMF was selected as the solvent, and nanodiamond was selected as the carrier. All materials were placed in a small beaker, sonicated and heated to accelerate solvent evaporation. After drying, the materials were placed in an oven to continue drying for 10 h. Then the materials were ground into fine powder and calcined in a tube furnace at 400℃ with Ar introduced for 1 h. The heating rate was 5℃ per minute. Finally, the Co-based catalytic material CoPc-Cl / ND was obtained.

[0045] (2) Peroxidase-like activity was tested using the TMB probe reaction: 180 mg of 3,3',5,5'-tetramethylbenzidine (TMB) was dissolved in 1 mL of dimethyl sulfoxide (DMSO) and wrapped in aluminum foil for storage in the dark. 1.64 g of sodium acetate was dissolved in 20 mL of water to obtain a sodium acetate stock solution. 11.8 mL of acetic acid was added to a final volume of 200 mL to obtain an acetic acid stock solution. 15 mL of the sodium acetate stock solution was mixed with 185 mL of the acetic acid stock solution to obtain an acetate-sodium acetate buffer solution with a pH of 3.6. The nanodrop (instrument for measuring absorbance) was heated to 37 °C. 965 μL of buffer solution and 5 μL of catalyst were added to a cuvette with a 1 cm optical path length, respectively, as a blank control. Then, 10 μL of TMB and 20 μL of H2O2 were added. The absorbance curve of the system at 400 s was tested, and the catalytic performance of the catalyst was judged by the curve trend.

[0046] (3) Prepare glucose solutions of different concentrations. First, prepare a 10 mmol / L glucose stock solution. Weigh 1.8 g of glucose and dissolve it in 1 L of acetate-sodium acetate buffer solution, which is called solution 1. After shaking, take 500 mL of solution 1 and mix it with 500 mL of acetate-sodium acetate buffer solution to obtain a 5 mmol / L glucose solution, which is called solution 2. And so on, to obtain a series of glucose solutions with concentrations of 10 mM, 5 mM, 2.5 mM, 1 mM, 0.5 mM, 0.25 mM and 0.1 mM. Weigh 10 mg of glucose oxidase and dissolve it in 10 mL of acetate-sodium acetate buffer solution to obtain a 1 mg / mL glucose oxidase solution. Wrap it in aluminum foil and store it at low temperature. Take 120 μL of glucose solution of different concentrations and add 20 μL of glucose oxidase solution. Incubate in a microplate reader at 37 °C for 1 h. Add the incubated mixed solution to a 96-well plate, and add 30 μL of CoPc-CL / ND and 30 μL of LTMB. Shake for 10 min and test its absorbance at 652 nm.

[0047] Comparative Example 1 This comparative example is basically the same as Example 1, except that no nanodiamond carrier is added in step (1), and the rest of the steps are the same as in Example 1.

[0048] In this comparative example, due to the lack of a support, Co single atoms could not be dispersed, resulting in extremely low activity and the inability to carry out subsequent cascade coupling reactions.

[0049] Comparative Example 2 This comparative example is basically the same as Example 1, except that glucose oxidase is not added in step (3), and Co-based catalytic material CoPc-NH2 / ND is used to detect glucose.

[0050] In this comparative example, the catalytic material did not have the ability to directly catalyze the oxidation of glucose substrate during the glucose detection process, so the glucose content could not be detected.

[0051] Comparative Example 3 Compared to Example 1, this comparative example did not prepare the Co-based catalytic material CoPc-NH2 / ND, but instead used a nanoparticle catalytic material with peroxidase activity to perform a cascade reaction with glucose oxidase.

[0052] In this comparative example, the glucose detection process was affected by too many interfering factors, making effective detection impossible.

[0053] Figure 1 shows the SEM images of Examples 1-3 of the present invention, where (a) is the SEM image of the Co-based catalyst CoPc-COOH / ND in Example 1 at 1 μm, (b) is the SEM image of the Co-based catalyst CoPc-COOH / ND in Example 2 at 1 μm, and (c) is the SEM image of the Co-based catalyst CoPc-Cl / ND in Example 3 at 1 μm. It can be seen from the figure that the cobalt-based catalysts of Examples 1-3 are all spherical, and the surface modification of different groups has no effect on the morphology of the catalyst.

[0054] Figure 2 shows (a) HAADF-STEM and EDS-Mapping diagrams of Example 1 of the present invention, (b) HAADF-STEM and EDS-Mapping diagrams of Example 2 of the present invention, and (c) HAADF-STEM and EDS-Mapping diagrams of Example 3 prepared according to the present invention. The figures show that Co was successfully loaded onto the nanodiamond and dispersed as single atoms.

[0055] Figure 3 shows the XRD patterns of the Co-based catalytic materials prepared in Examples 1-3 of this invention. It can be seen that the two peaks on the XRD belong to the (111) and (220) planes of the nanodiamond support, and the loaded Co atoms did not affect the support.

[0056] Figure 4 shows the BET diagrams of the Co-based catalytic materials prepared in Examples 1-3 of this invention. It can be seen that the prepared catalytic materials all have the same H3-type hysteresis loop, and the preparation process did not damage the support.

[0057] Figure 5 shows the XPS spectrum of the Co-based catalytic material prepared in Example 1 of the present invention, which shows that Co-N bonds were formed during the preparation process.

[0058] Figure 6 shows the peroxidase-like activity reaction kinetics of the Co-based catalytic materials prepared in Examples 1-3 of the present invention. It can be seen that the performance of the materials with different modifications has changed, but all of them are higher than those of the pure support. Among them, the Co-based catalytic material CoPc-NH2 / ND in Example 1 has the best performance.

[0059] Figure 7 shows the optimal condition screening results of Example 1 of the present invention, where (a) is the TMB concentration, (b) is the H2O2 concentration and (c) is the pH value. It can be seen that the Co-based catalytic material of Example 1 has the best enzyme activity at pH 4.0 and H2O2 20 mmol / L.

[0060] Figure 8 shows the glucose sensing results of Example 1 prepared according to the present invention, where (a) is the glucose sensing performance, (b) is the glucose selectivity, and (c) is the system's anti-interference ability. The results show that the system of Example 1 coupled with glucose oxidase has a linear detection range of 0.1-1.0 and has excellent selectivity and high anti-interference ability for glucose.

[0061] The above embodiments are some implementations of the present invention, but the implementation of the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall fall within the protection scope of the present invention.

Claims

1. A Co-based catalytic material for glucose sensing, characterized in that, The Co-based catalytic material contains highly dispersed Co-N4 enzyme-mimicking sites, which are highly similar to the electronic structure and coordination microenvironment of natural peroxidase.

2. The Co-based catalytic material for glucose sensing according to claim 1, characterized in that, The surface of the Co-based catalytic material has different modifying groups, which are one of amino, carboxyl, or chlorine groups, used to adjust the catalytic activity of the Co-based catalytic material.

3. A method for preparing a Co-based catalytic material for glucose sensing, characterized in that, The preparation method includes reacting a Co-containing precursor with a nanodiamond support in a solvent using an equal-volume impregnation method, drying the mixture, and then calcining it in a tube furnace under an inert gas atmosphere to obtain the Co-based catalytic material.

4. The method for preparing a Co-based catalytic material for glucose sensing according to claim 3, characterized in that, The Co-containing precursor is one of tetraaminocobalt phthalocyanine, tetracarboxycobalt phthalocyanine, and perchlorocobalt phthalocyanine.

5. The method for preparing a Co-based catalytic material for glucose sensing according to claim 4, characterized in that, In the Co-containing precursor, the Co loading is 0.5%.

6. The method for preparing a Co-based catalytic material for glucose sensing according to claim 3, characterized in that, The solvent is one of N,N-dimethylformamide, dimethyl sulfoxide, ethyl acetate, acetonitrile, isopropanol, and n-hexane.

7. The method for preparing a Co-based catalytic material for glucose sensing according to claim 3, characterized in that, The drying temperature is 60℃-100℃, the inert atmosphere is argon or nitrogen, the calcination temperature is 300℃-600℃, and the calcination time is 1 h-2 h.

8. An application of a Co-based catalytic material in the preparation of a glucose sensor, wherein the Co-based catalytic material according to any one of claims 1-2 or the Co-based catalytic material prepared by any one of claims 3-7 is coupled with a glucose oxidase cascade to construct an enzyme-enzyme composite sensing system for glucose detection.

9. The application according to claim 8, characterized in that, In the process of glucose detection by the enzyme-enzyme composite sensing system, glucose is first oxidized to hydrogen peroxide by glucose oxidase, and then hydrogen peroxide is oxidized by the Co-N4 enzyme-like site of the Co-based catalytic material, thereby achieving quantitative detection of glucose.

10. The application according to claim 8, characterized in that, The linear detection range for glucose concentration is 0.1-1.0 mM.

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