Non-enzymatic multifunctional sensor electrode material, preparation method, sensor and application
By preparing the Co@NC/Co3O4 non-enzyme multifunctional sensor electrode material, the problems of high cost and poor stability of enzyme-based sensors have been solved, and highly sensitive detection of glucose and hydrogen peroxide has been achieved. It has good catalytic activity and stability and is suitable for non-enzyme multifunctional sensors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2026-03-24
- Publication Date
- 2026-05-22
AI Technical Summary
Existing enzyme-based electrochemical sensors are expensive and have poor stability, which limits their practical application in the detection of H2O2 and glucose.
Using cobalt salts, urea, melamine, and carbon nanotubes as raw materials, Co@NC/Co3O4 non-enzymatic multifunctional sensor electrode materials were prepared through hydrothermal reaction and heat treatment, forming a three-layer composite structure of carbon-nitrogen-coated metallic cobalt and Co3O4 nanoparticles, thus constructing a non-enzymatic multifunctional sensor.
It achieves highly sensitive detection of glucose and hydrogen peroxide, exhibits good catalytic activity, stability, and a wide linear response range, and is low in cost and simple in process, making it suitable for large-scale mass production.
Smart Images
Figure CN122072253A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of non-enzymatic electrochemical sensor technology, and particularly to non-enzymatic multifunctional sensor electrode materials and preparation methods, sensors and applications. Background Technology
[0002] Currently, various analytical methods have been developed for detecting hydrogen peroxide (H2O2) and glucose, including colorimetric methods, fluorescence methods, chemiluminescence methods, and optical thermoelectric methods. Compared with these technologies, electrochemical detection methods have attracted much attention due to their low cost, speed, high sensitivity, and good selectivity. Among various electrochemical sensors, enzyme-based electrochemical sensors can achieve rapid responses to H2O2 and glucose, exhibiting high sensitivity and specificity. However, natural enzymes are expensive, have poor stability, and are affected by environmental factors to some extent, limiting their practical application in the detection of H2O2 and glucose.
[0003] Therefore, existing technologies still need to be improved and developed. Summary of the Invention
[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a non-enzyme multifunctional sensor electrode material and preparation method, sensor and application, aiming to solve the problems of high cost and poor stability of existing enzyme-based electrochemical sensors.
[0005] The technical solution of the present invention is as follows: A first aspect of the present invention provides a method for preparing a non-enzymatic multifunctional sensor electrode material, characterized in that it comprises: Step S1: Mix cobalt salt, urea, melamine, carbon nanotubes and water at room temperature for 4-12 hours to obtain a mixture; wherein, the mass ratio of cobalt salt, urea, melamine and carbon nanotubes is 7.5-30:2-12:5-20:1-4. Step S2: The mixture is subjected to a hydrothermal reaction at 110~130℃ for 12~18h to obtain a solid powder; Step S3: Heat the solid powder to 400-800℃ at a heating rate of 2.5-5℃ / min under an inert atmosphere for 2-3 hours to obtain Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material; The Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material is a three-layer composite structure based on carbon-nitrogen coated metallic cobalt, with Co3O4 nanoparticles grown on the outermost surface.
[0006] Optionally, the cobalt salt is cobalt oxalate or cobalt acetate.
[0007] Optionally, the mass ratio of the cobalt salt, urea, melamine, and carbon nanotubes is 1.5:0.6:1:0.228.
[0008] Optionally, step S2 further includes: After the hydrothermal reaction is completed, the system is filtered, washed, and dried to obtain the solid powder.
[0009] Optionally, the drying temperature is 60~80℃ and the time is 8~12h.
[0010] Optionally, the inert atmosphere is nitrogen.
[0011] Optionally, the Co3O4 nanoparticles on the surface are directly connected to the internal elemental cobalt, and multiple nanosphere clusters form a three-dimensional porous nanorod structure with abundant pores inside, wherein the average particle size of the nanospheres is distributed between 30 and 70 nm.
[0012] In a second aspect, the present invention provides a non-enzyme multifunctional sensor electrode material according to the present invention, wherein the non-enzyme multifunctional sensor electrode material is prepared by the material preparation method.
[0013] A third aspect of the present invention provides a non-enzyme multifunctional sensor, comprising an electrode and an electrode material coated on the surface of the electrode, wherein the electrode material comprises the non-enzyme multifunctional sensor electrode material of the present invention.
[0014] A fourth aspect of the present invention provides an application of the non-enzymatic multifunctional sensor described herein in the detection of glucose or hydrogen peroxide.
[0015] Beneficial Effects: The preparation method of the non-enzymatic multifunctional sensor electrode material provided by this invention is low-cost and simple. The obtained Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material is based on carbon-nitrogen-coated metallic cobalt, with a unique three-layer composite structure formed by growing Co3O4 nanoparticles on the outermost surface. The surface Co3O4 nanoparticles and the internal metallic cobalt are directly connected, while multiple nanosphere clusters form a three-dimensional porous nanorod structure with abundant internal pores. Due to its unique structure, this non-enzymatic multifunctional sensor electrode material exhibits excellent catalytic activity for glucose and hydrogen peroxide. Non-enzymatic multifunctional sensors constructed using this material can achieve highly sensitive detection of glucose or hydrogen peroxide, while also exhibiting a wide linear response range, good detection stability and consistency, showing great application potential. Attached Figure Description
[0016] Figure 1 A flowchart illustrating a method for preparing a non-enzymatic multifunctional sensor electrode material provided by the present invention.
[0017] Figure 2 The image shows the overall SEM distribution morphology of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1.
[0018] Figure 3 The image shows the SEM microstructure of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1.
[0019] Figure 4 This is a TEM image of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1.
[0020] Figure 5 The image shows the XRD pattern of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1.
[0021] Figure 6 The graph shows the response of the presence or absence of glucose in solution to changes in current using cyclic voltammetry.
[0022] Figure 7 This is a graph showing the amperometric current response for glucose concentration detection using the amperometric method.
[0023] Figure 8 Linear regression curve of amperometric current response for glucose concentration detection using the amperometric method.
[0024] Figure 9 The amperometric current response curves for the detection of glucose, L-phenylalanine, glycine, and sodium chloride using the amperometric method are shown.
[0025] Figure 10 The graph shows the response of the presence or absence of hydrogen peroxide in solution to changes in current using cyclic voltammetry.
[0026] Figure 11 The amperometric current response curve for detecting hydrogen peroxide concentration using the amperometric method is shown.
[0027] Figure 12 The linear regression curve of the amperometric current response for detecting hydrogen peroxide concentration using the amperometric method is shown.
[0028] Figure 13 The amperometric current response curves for detecting hydrogen peroxide, sodium chloride, sodium nitrite, ammonium sulfate, and urea using the amperometric method are shown. Detailed Implementation
[0029] This invention provides a non-enzymatic multifunctional sensor electrode material and its preparation method, as well as the sensor and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0030] like Figure 1 As shown, this embodiment of the invention provides a method for preparing a non-enzymatic multifunctional sensor electrode material, comprising: Step S1: Mix cobalt salt, urea, melamine, carbon nanotubes and water at room temperature for 4-12 hours to obtain a mixture; wherein, the mass ratio of cobalt salt, urea, melamine and carbon nanotubes is 7.5-30:2-12:5-20:1-4. Step S2: The mixture is subjected to a hydrothermal reaction at 110~130℃ for 12~18h to obtain a solid powder; Step S3: Heat the solid powder to 400-800℃ at a heating rate of 2.5-5℃ / min under an inert atmosphere for 2-3 hours to obtain Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material; The Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material is a three-layer composite structure based on carbon-nitrogen coated metallic cobalt, with Co3O4 nanoparticles grown on the outermost surface.
[0031] This invention selects cobalt salt, urea, melamine, and carbon nanotubes as raw materials. These raw materials are widely available and inexpensive. Cobalt salt provides the cobalt source, urea provides the nitrogen source for carbon-nitrogen coating, and carbon nanotubes provide the carbon source for carbon-nitrogen coating. Melamine acts as a reducing agent, reducing cobalt ions to metallic cobalt during the reaction and also providing a nitrogen source. These raw materials are mixed with water to form a solution, and then subjected to a hydrothermal reaction and heat treatment. The hydrothermal reaction provides a high-temperature, high-pressure environment for the raw materials to undergo initial chemical reactions. The heat treatment provides a good reduction environment for the product, ensuring its stability at room temperature after reduction, thus yielding the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material. This method is low-cost, simple, and suitable for large-scale mass production.
[0032] The Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in this invention has a unique three-layer composite structure based on carbon-nitrogen-coated metallic cobalt, with Co3O4 nanoparticles grown on the outermost surface. The surface Co3O4 nanoparticles are directly connected to the internal metallic cobalt, while multiple nanosphere clusters form a three-dimensional porous nanorod structure with abundant internal pores. Cobalt, as a transition metal, is inexpensive, environmentally friendly, electrochemically sensitive, and abundant. Carbon nanotubes themselves have a larger specific surface area and better conductivity. After combining with nitrogen to form a carbon-nitrogen coating, the synthesized material can better maintain its original valence state, significantly improving its stability and conductivity. Simultaneously, the outermost Co3O4 nanoparticles provide a large number of reactive sites for the detection of glucose and hydrogen peroxide. The unique structure of this material gives it excellent catalytic activity for glucose and hydrogen peroxide, making it suitable for constructing non-enzymatic multifunctional sensors to achieve highly sensitive detection of glucose or hydrogen peroxide.
[0033] The Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in this embodiment of the invention benefits from the thorough reduction effect of the secondary heat treatment. The carbon-nitrogen-coated cobalt metal exhibits a nanosphere structure with an average particle size distribution between 30 and 70 nm. This fine nanosphere structure provides a larger specific surface area for the catalytic oxidation of glucose and the detection of hydrogen peroxide. Simultaneously, Co3O4 nanoparticles with a diameter of approximately 10 nm grow on the surface of the carbon-nitrogen-coated cobalt metal. These nanoparticles directly connect to the cobalt metal within the carbon-nitrogen-coated metal, forming a highly efficient heterostructure that serves as an active site for catalytic oxidation. This heterostructure not only ensures rapid electron migration but also effectively prevents the dissolution and loss of Co3O4 during electrocatalysis due to the lattice oxygen reaction mechanism (LOM), thus providing a solid theoretical basis for the high sensitivity and stability of the catalytic reaction.
[0034] In some embodiments, the cobalt salt is cobalt oxalate or cobalt acetate. Preferably, the cobalt salt is cobalt oxalate, which is insoluble in water, inexpensive, and can be extracted from waste batteries. Furthermore, its water-insoluble nature allows it to serve as a carbon-encapsulated substrate in hydrothermal reactions.
[0035] In some embodiments, the mass ratio of the cobalt salt, urea, melamine, and carbon nanotubes is 1.5:0.6:1:0.228.
[0036] In step S1, the mixing and stirring temperature is room temperature, and the time is 4~12h (e.g., 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, etc.). The mixing and stirring must be maintained for a sufficient amount of time to ensure that the initial reaction can proceed completely; at the same time, the stirring must be carried out at room temperature to prevent the occurrence of new unknown reactions due to excessively high temperatures.
[0037] In some embodiments, step S2 further includes: after the hydrothermal reaction is completed, the system is filtered, washed and dried to obtain the solid powder.
[0038] In some embodiments, the drying temperature is 60~80°C (e.g., 60°C, 70°C, 80°C, etc.), and the time is 8~12h (e.g., 8h, 9h, 10h, 11h, 12h, etc.).
[0039] In step S2, the hydrothermal reaction temperature is 110~130℃ (e.g., 110℃, 120℃, 130℃, etc.), and the time is 12~18h (e.g., 12h, 13h, 14h, 15h, 16h, 17h, 18h, etc.). In this hydrothermal reaction, the reaction temperature needs to be controlled. Too high a temperature will lead to a violent reaction that fails to form a uniform and stable structure, while too low a temperature will result in amorphous materials or materials with many defects. Simultaneously, the reaction time needs to be controlled to be above 12h to ensure that the material can fully crystallize.
[0040] In step S3, the heat treatment atmosphere is an inert atmosphere (such as nitrogen), the temperature is 400~800℃ (e.g., 400℃, 500℃, 600℃, 700℃, 800℃, etc.), the heating rate is 2.5~5℃ / min (e.g., 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, 5℃ / min, etc.), and the time is 2~3h (e.g., 2h, 2.5h, 3h, etc.). Under these heat treatment conditions, the reaction intermediates will not be rapidly converted due to excessively high heating rates, which would ultimately affect crystallization; at the same time, the reaction is ensured to last for more than 2 hours, allowing the material to react fully in an inert atmosphere.
[0041] This invention provides a method for preparing a non-enzyme multifunctional sensor electrode material as described in any of the preceding embodiments. The prepared non-enzyme multifunctional sensor electrode material (Co@NC / Co3O4) is based on carbon-nitrogen-coated metallic cobalt, with a unique three-layer composite structure formed by growing Co3O4 nanoparticles on the outermost surface. The surface Co3O4 nanoparticles are directly connected to the inner metallic cobalt (i.e., it can be considered as the carbon-nitrogen-coated metallic cobalt "emerging" and growing Co3O4 nanoparticles on the surface). Simultaneously, multiple nanosphere clusters form a three-dimensional porous nanorod structure with abundant internal pores. This unique three-layer composite structure protects the valence state of the innermost cobalt, exhibiting excellent stability and conductivity. Furthermore, the pores formed by its aggregation have a larger specific surface area. The Co3O4 nanoparticles grown on the outermost surface provide numerous reactive sites for the detection of glucose and hydrogen peroxide. Therefore, this material can be used to design a highly efficient, sensitive, highly selective, low-cost, and highly stable non-enzyme multifunctional sensor for the efficient detection of glucose or hydrogen peroxide.
[0042] This invention provides a non-enzyme multifunctional sensor, including an electrode and an electrode material coated on the surface of the electrode, wherein the electrode material includes the non-enzyme multifunctional sensor electrode material described in the foregoing embodiments.
[0043] This invention provides an application of the non-enzymatic multifunctional sensor described in the foregoing embodiments in the detection of glucose or hydrogen peroxide. Because the non-enzymatic multifunctional sensor has a Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material coated on its electrode surface, it can achieve highly sensitive detection of glucose or hydrogen peroxide, exhibiting good catalytic activity, while also possessing a wide linear response range, good stability, and reproducibility.
[0044] The present invention will be further described below through specific embodiments.
[0045] Example 1 This embodiment provides a method for preparing a Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material, including the following steps: Prepare a urea solution by mixing 0.6g of urea powder with 40mL of deionized water. Then add 1.5g of cobalt oxalate (CoC2O4) powder, 1g of melamine powder and 0.228g of carbon nanotube powder to the urea solution and stir at room temperature for 4 hours to allow it to react fully and obtain a mixed solution. The obtained mixture was transferred to a high-pressure hydrothermal reactor and reacted at 120°C for 12 hours. After natural cooling to room temperature, the mixture was transferred to a vacuum filter for filtration and washed three times with deionized water. The resulting blackish-gray precipitate was collected and transferred to an oven for drying. It was dried at 60°C for 10 hours to obtain a blackish-gray powder. After thoroughly mixing the obtained dark gray powder mechanically, it was transferred into a small ceramic boat. Nitrogen gas was first introduced into the tube furnace for 30 minutes to ensure that the heating system was filled with nitrogen. Then, it was heated to 500°C in a nitrogen atmosphere at a heating rate of 5°C / min for 2 hours. After cooling, it was taken out to obtain the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material.
[0046] Example 2 This embodiment provides a method for preparing a non-enzymatic multifunctional sensor, including the following steps: A water / Nafion mixed solution was prepared by mixing water and Nafion 117 perfluorinated resin solution at a volume ratio of 9:1. The Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1 was mixed with the water / Nafion mixed solution at a concentration of 3 mg / mL, and then ultrasonicated in an ultrasonic bath to obtain a dispersion solution. 10 μL of the dispersion solution was transferred to a glassy carbon electrode using a pipette and evenly coated on the surface of the glassy carbon electrode. After natural drying, the non-enzymatic multifunctional sensor was obtained.
[0047] Performance testing: (1) The morphology and structure of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1 were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD).
[0048] Figure 2 This is a SEM image of the overall distribution morphology of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1. Figure 3 This is a SEM microstructure image of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1. Figure 4 The image shows a TEM image of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1. Co (002) represents the interplanar spacing measured by the TEM image, and the specific crystal plane of elemental cobalt at this angle is obtained by reverse calculation. (002) represents the crystal plane index to which the Co crystal plane points. Co3O4 (111) represents the interplanar spacing measured by the TEM image, and the specific crystal plane of cobalt tetroxide at this angle is obtained by reverse calculation. (111) represents the crystal plane index to which the Co3O4 crystal plane points. Figure 5This is the XRD pattern of the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared in Example 1.
[0049] according to Figures 2 to 5 It is known that the Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material prepared by the present invention is based on carbon and nitrogen coated metallic cobalt, and a unique three-layer composite structure is formed by growing Co3O4 nanoparticles on the outermost surface. The Co3O4 nanoparticles on the surface and the metallic cobalt inside are directly connected, and multiple nanosphere clusters form a three-dimensional porous nanorod structure with abundant pores inside.
[0050] (2) Investigation of the glucose detection performance of the non-enzyme multifunctional sensor prepared in Example 2: The non-enzyme multifunctional sensor prepared in Example 2 was used as the working electrode, forming a three-electrode system with a platinum electrode (counter electrode) and an Ag / AgCl reference electrode. The three-electrode system was immersed in 0.1M NaOH solution, and the current change was tested by cyclic voltammetry, with a voltage range of -0.15~0.65V. After the test, a quantitative glucose solution was added dropwise to the 0.1M NaOH solution to make the glucose concentration 5mM. Cyclic voltammetry was performed under the same conditions as before, and a second current response curve was obtained. The two curves were then superimposed and plotted.
[0051] Figure 6 The graph shows the response of the presence or absence of glucose in the solution to the change in current using cyclic voltammetry. It can be seen from the graph that the current density increases significantly after the addition of glucose, which proves that glucose has a significant catalytic effect on the sensor, especially in the voltage range of 0.4~0.65V, where the current density is even greater when glucose is present in the solution.
[0052] (3) To investigate the glucose detection performance of the non-enzyme multifunctional sensor prepared in Example 2, the amperometric method was used. The non-enzyme multifunctional sensor prepared in Example 2 was used as the working electrode, forming a three-electrode system with a platinum electrode (counter electrode) and an Ag / AgCl reference electrode. The three-electrode system was immersed in 0.1M NaOH solution, and the solution volume was recorded for subsequent testing. In addition, glucose test solutions of different concentrations were prepared. The above three-electrode system was connected to an electrochemical workstation, and glucose test solutions of different concentrations were added to 0.1M NaOH solution, so that the glucose concentration changes after adding glucose test solutions were 0.01mM, 0.1mM, and 1mM, respectively. The detection voltage was 0.55V.
[0053] Figure 7This is an amperometric current response curve for glucose concentration detection using the amperometric method. The inset is a magnified view of the 0.01mM~0.3mM range. It can be seen that there is a current response in the glucose concentration range of 10μM~15000μM, which has a wide linear response range and fast current response. It can accurately measure the glucose concentration, and the extremely low detection limit ensures the accuracy of the detection.
[0054] Through the Figure 7 After performing linear regression analysis, the regression curve was obtained. Figure 8 This is a linear regression curve of the amperometric current response for detecting glucose concentration using the amperometric method. Therefore, the concentration of glucose in the test solution can be inferred from the current density of the test solution obtained by detection.
[0055] (4) To investigate the anti-interference detection performance of the non-enzyme multifunctional sensor prepared in Example 2 for glucose, the specific method is to test the current response curve of the sensor by amperometric method. After the curve stabilizes, glucose, interfering agent L-phenylalanine, interfering agent glycine, and interfering agent sodium chloride are added respectively. The concentration of glucose test solution is 1mM, the concentration of interfering agent is 0.1mM, and the test voltage is 0.55V.
[0056] Figure 9 The graph shows the amperometric current response curves for detecting glucose, L-phenylalanine, glycine, and sodium chloride using the amperometric method. It can be seen that the non-enzymatic multifunctional sensor of the present invention exhibits good selectivity for glucose, but almost no current response for L-phenylalanine, glycine, etc.
[0057] (5) Investigation of the detection performance of the non-enzyme multifunctional sensor prepared in Example 2 for hydrogen peroxide: The non-enzyme multifunctional sensor prepared in Example 2 was used as the working electrode, and a three-electrode system was formed with a platinum electrode (counter electrode) and an Ag / AgCl reference electrode. The three-electrode system was immersed in 0.1M NaOH solution, and the current change was tested by cyclic voltammetry, with a voltage range of -0.65~0V. After the test, a quantitative amount of hydrogen peroxide solution was added to 0.1M NaOH to make the hydrogen peroxide concentration 1mM. Cyclic voltammetry was performed under the same conditions as before, and a second current response curve was obtained. The two curves were superimposed and plotted.
[0058] Figure 10 The graph shows the response of the presence or absence of hydrogen peroxide in the solution to the change in current using cyclic voltammetry. As can be seen from the graph, the current density increases significantly after the addition of hydrogen peroxide, which proves that hydrogen peroxide has a significant catalytic effect on the sensor, especially in the voltage range of -0.25 to -0.55 V, where the current density is even greater when hydrogen peroxide is present in the solution.
[0059] (6) To investigate the detection performance of the non-enzyme multifunctional sensor prepared in Example 2 for hydrogen peroxide, the amperometric method was used in the same way. The non-enzyme multifunctional sensor prepared in Example 2 was used as the working electrode, and a three-electrode system was formed with a platinum electrode (counter electrode) and an Ag / AgCl reference electrode. The three-electrode system was immersed in 0.1M NaOH solution, and the volume of the solution was recorded for subsequent testing. In addition, hydrogen peroxide test solutions of different concentrations were prepared. The above three-electrode system was connected to an electrochemical workstation, and hydrogen peroxide test solutions of different concentrations were added to 0.1M NaOH solution, so that the concentration changes of hydrogen peroxide after adding hydrogen peroxide test solutions were 40μM, 200μM, 1mM, and 2mM, respectively. The detection voltage was -0.35V.
[0060] Figure 11 This is an amperometric current response curve for detecting hydrogen peroxide concentration using the amperometric method. The inset is a magnified view of the 120μM~600μM range. It can be seen that there is a current response in the range of hydrogen peroxide concentration from 40μM to 14000μM, which has a wide linear response range and fast current response, and can accurately measure the hydrogen peroxide concentration.
[0061] Through the Figure 11 After performing linear regression analysis, the regression curve was obtained. Figure 12 This is a linear regression curve of the amperometric current response for detecting hydrogen peroxide concentration using the amperometric method. Therefore, the concentration of hydrogen peroxide in the test solution can be inferred from the current density of the test solution obtained by detection.
[0062] (7) To investigate the anti-interference detection performance of the non-enzyme multifunctional sensor prepared in Example 2 against hydrogen peroxide, the specific method is to test the current response curve of the sensor by amperometric method. After the curve stabilizes, hydrogen peroxide, sodium chloride, sodium nitrite, ammonium sulfate and urea are added respectively. The concentration of hydrogen peroxide in the test solution is 1 mM, the concentration of the interfering agent is 0.1 mM, and the test voltage is -0.35 V.
[0063] Figure 13 The graph shows the amperometric current response curves for detecting hydrogen peroxide, sodium chloride, sodium nitrite, ammonium sulfate, and urea using the amperometric method. It can be seen that the non-enzymatic multifunctional sensor of the present invention exhibits good selectivity for hydrogen peroxide, but no obvious current response for sodium chloride, sodium nitrite, ammonium sulfate, urea, etc.
[0064] In summary, this invention successfully prepared a Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material using the described method. Based on carbon-nitrogen-coated metallic cobalt, the outermost surface is covered with Co3O4 nanoparticles, forming a unique three-layer composite structure. The surface Co3O4 nanoparticles and the internal metallic cobalt are directly connected, while multiple nanosphere clusters form a three-dimensional porous nanorod structure with abundant internal pores. Due to its unique structure, this non-enzymatic multifunctional sensor electrode material exhibits excellent catalytic activity for glucose and hydrogen peroxide. The non-enzymatic multifunctional sensor prepared using this material can achieve highly sensitive detection of glucose or hydrogen peroxide, while also possessing a wide linear response range, good detection stability and consistency, demonstrating promising application prospects.
[0065] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A method for preparing a non-enzymatic multifunctional sensor electrode material, characterized in that, include: Step S1: Mix cobalt salt, urea, melamine, carbon nanotubes and water at room temperature for 4-12 hours to obtain a mixture; wherein, the mass ratio of cobalt salt, urea, melamine and carbon nanotubes is 7.5-30:2-12:5-20:1-4. Step S2: The mixture is subjected to a hydrothermal reaction at 110~130℃ for 12~18h to obtain a solid powder; Step S3: Heat the solid powder to 400-800℃ at a heating rate of 2.5-5℃ / min under an inert atmosphere for 2-3 hours to obtain Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material; The Co@NC / Co3O4 non-enzymatic multifunctional sensor electrode material is a three-layer composite structure based on carbon-nitrogen coated metallic cobalt, with Co3O4 nanoparticles grown on the outermost surface.
2. The method for preparing the non-enzymatic multifunctional sensor electrode material according to claim 1, characterized in that, The cobalt salt is cobalt oxalate or cobalt acetate.
3. The method for preparing the non-enzymatic multifunctional sensor electrode material according to claim 1, characterized in that, The mass ratio of the cobalt salt, urea, melamine, and carbon nanotubes is 1.5:0.6:1:0.
228.
4. The method for preparing the non-enzymatic multifunctional sensor electrode material according to claim 1, characterized in that, Step S2 further includes: After the hydrothermal reaction is completed, the system is filtered, washed, and dried to obtain the solid powder.
5. The method for preparing the non-enzymatic multifunctional sensor electrode material according to claim 4, characterized in that, The drying temperature is 60~80℃, and the time is 8~12h.
6. The method for preparing the non-enzymatic multifunctional sensor electrode material according to claim 1, characterized in that, The inert atmosphere is nitrogen.
7. The method for preparing the non-enzymatic multifunctional sensor electrode material according to claim 1, characterized in that, The surface Co3O4 nanoparticles are directly connected to the internal elemental cobalt, while multiple nanosphere clusters form a three-dimensional porous nanorod structure with abundant pores inside. The average particle size of the nanospheres is distributed between 30 and 70 nm.
8. A non-enzyme multifunctional sensor electrode material prepared by the preparation method of the non-enzyme multifunctional sensor electrode material according to any one of claims 1 to 7.
9. A non-enzyme multifunctional sensor, comprising electrodes and an electrode material coated on the surface of the electrodes, characterized in that, The electrode material includes the non-enzyme multifunctional sensor electrode material as described in claim 8.
10. The application of the non-enzymatic multifunctional sensor of claim 9 in the detection of glucose or hydrogen peroxide.