Metal-doped carbon dot nano-enzyme as well as preparation method and application thereof
Metal-doped carbon dot nanozymes were prepared by solid-phase pyrolysis, which solved the problems of drug resistance and stability of traditional antibacterial agents and natural enzyme materials, achieving efficient and environmentally friendly fruit preservation and extending the shelf life of fruits.
Patent Information
- Application Number
- CN202511416296.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2026-01-16
AI Technical Summary
Existing traditional antibacterial agents and natural enzyme materials suffer from problems such as drug resistance, insufficient catalytic activity, potential toxicity, and poor stability, which limit their widespread application. Furthermore, they are costly, difficult to store, and cannot meet the needs of fruit preservation.
Metal-doped carbon dot nanozymes were prepared by solid-phase pyrolysis. The crude carbon dots were obtained by dehydration polymerization of a mixture of polybasic acid and polyamine. The crude carbon dots were then mixed with metal salts and dissolved, followed by reverse precipitation to obtain metal-doped carbon dot nanozymes, which were then applied to fruit preservation.
The prepared metal-doped carbon nanoparticles have high catalytic activity, low toxicity, and excellent water solubility, which can extend the shelf life of fruits and achieve efficient and environmentally friendly antibacterial and preservation effects.
Smart Images
Figure CN121342002A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a metal-doped carbon dot nanozyme, its preparation method, and its application, belonging to the field of energy nanomaterials. Background Technology
[0002] Common traditional antibacterial agents mainly include synthetic and natural antibacterial agents found in food, such as vanillin, lysozyme, and plant polyphenols, as well as some emerging nanomaterials, including metal nanoparticles and composite nanoparticles. However, these traditional methods are limited by drug resistance, lack of catalytic activity, or potential toxicity, making them difficult to apply widely. Therefore, there is a need to develop new materials that are high-performance, efficient, and environmentally friendly.
[0003] Furthermore, natural enzymes utilize available elements and molecular structures to catalyze various biochemical reactions to maintain the normal metabolic and physiological functions of organisms. However, their high cost, poor stability, and difficulty in storage severely hinder their application.
[0004] Carbon dots (CDs) are widely used in the design of nanozymes. Their abundant surface functional groups, such as carboxyl and amino groups, facilitate chelation with various metal ions. The resulting metal-doped carbon dot nanozymes effectively prevent metal ion aggregation and exhibit excellent water solubility, biocompatibility, high catalytic activity, and low toxicity. Metal-doped carbon dots can generate different types of reactive oxygen species, such as superoxide radicals and hydroxyl radicals, allowing for the design of nanozymes including peroxidases and superoxide dismutases. Therefore, metal-doped carbon dot materials can serve as nanozymes to mimic the biocatalytic performance of natural enzymes and are widely used in catalytic degradation, antibacterial, and bacteriostatic applications. Summary of the Invention
[0005] The purpose of this invention is to develop a metal-doped carbon dot nanozyme, its preparation method, and its application. The preparation method includes: (1) dehydrating and polymerizing a mixture containing polybasic acids and polyamines using solid-phase pyrolysis to obtain crude carbon dots; (2) dissolving the crude carbon dots in a solvent and precipitating them in reverse phase to obtain purified carbon dots; and (3) mixing and dissolving the purified carbon dots with a metal salt and precipitating them in reverse phase to obtain the metal-doped carbon dot nanozyme. This preparation method is simple, fast, and has a high yield, and can be used for fruit preservation.
[0006] The metal-doped carbon dot nanozymes prepared in this application can generate long-lived free radicals and have excellent catalytic oxidation performance. Therefore, metal-doped carbon dot nanozymes can be used to preserve fruits and extend their shelf life.
[0007] According to a first aspect of this application, a method for preparing metal-doped carbon dot nanozymes is provided, the method comprising: (1) A mixture containing polybasic acids and polyamines was dehydrated and polymerized by solid-phase pyrolysis to obtain crude carbon dots; (2) Dissolve the crude carbon dots in a solvent and precipitate them by reverse phase to obtain purified carbon dots; (3) The purified carbon dots are mixed and dissolved with metal salt, and the metal-doped carbon dot nanozyme is obtained by reverse precipitation.
[0008] Optionally, in step (1), the polyacid is a polycarboxylic acid; the polycarboxylic acid is selected from at least one of tricornioic acid, succinic acid, and malonic acid.
[0009] Optionally, the polyamine is selected from at least one of m-phenylenediamine, p-phenylenediamine, and o-phenylenediamine.
[0010] Optionally, the molar ratio of the polyacid to the polyamine is 0.5~2 : 1~6.
[0011] Optionally, in step (1), the pyrolysis temperature is 150~300 ℃ and the time is 1~8 hours.
[0012] Optionally, in step (1), the upper limit of the pyrolysis temperature is independently selected from 300℃, 250℃, and 200℃, and the lower limit is independently selected from 150℃, 250℃, and 200℃; the upper limit of the pyrolysis time is independently selected from 8 hours, 6 hours, 4 hours, and 2 hours, and the lower limit is independently selected from 1 hour, 6 hours, 4 hours, and 2 hours.
[0013] Optionally, in step (2), the solvent includes one of methanol-acetonitrile, chloroform-toluene, and acetone-n-hexane.
[0014] Optionally, in step (3), the metal salt is selected from at least one of ferric chloride, copper chloride, and cobalt chloride; Preferably, in step (3), the mass ratio of the carbon dots to the metal salt is 1:0.5~3; Optionally, in step (3), the upper limit of the mass ratio of the carbon point to the metal salt is independently selected from 1:0.5, 1:1.5, and 1:2.5, and the lower limit is independently selected from 1:3, 1:1.5, and 1:2.5.
[0015] Preferably, in step (3), the solvent used includes one of dimethyl sulfoxide-water, ethanol-dichloromethane, and methanol-acetonitrile combination.
[0016] According to a second aspect of this application, a metal-doped carbon dot nanozyme is provided, the metal-doped carbon dot nanozyme comprising at least one of the metal-doped carbon dot nanozymes prepared according to the above preparation method.
[0017] According to a third aspect of this application, an application of the aforementioned metal-doped carbon nanoparticle nanozyme in antibacterial preservation is provided.
[0018] Optionally, the application method includes: dispersing the metal-doped carbon nanoparticles in water, soaking or spraying the substance to be antibacterial and preserved, so as to achieve the antibacterial and preservation function; Preferably, the concentration of the metal-doped carbon nanoparticle nanozyme dispersed in water is 0.1~5 mg / mL.
[0019] Optionally, the upper limit of the concentration of the metal-doped carbon nanoparticle nanozyme dispersed in water is independently selected from 5 mg / mL, 4 mg / mL, 3 mg / mL, 2 mg / mL, 1 mg / mL, and 0.5 mg / mL, and the lower limit is independently selected from 0.1 mg / mL, 4 mg / mL, 3 mg / mL, 2 mg / mL, 1 mg / mL, and 0.5 mg / mL.
[0020] The beneficial effects that this application can produce include: (1) Metal-doped carbon nanoparticles have advantages such as high synthesis efficiency and high purity; (2) Metal doping is a simple and quick method with high yield; (3) Metal-doped carbon nanoparticles have long-lived free radical properties; (4) Metal-doped carbon nanoparticles are low in toxicity; (5) Metal-doped carbon nanoparticles can be used for fruit preservation. Attached Figure Description
[0021] Figure 1 The image shows the ultraviolet absorption spectrum of the iron-doped carbon nanoparticle nanozyme in Example 1.
[0022] Figure 2 The infrared spectrum of the iron-doped carbon dot nanozyme in Example 1 is shown.
[0023] Figure 3 This is a diagram of the oxidation catalyzed by the iron-doped carbon dot nanozyme in Example 1.
[0024] Figure 4 This is a diagram showing the antibacterial and antimicrobial activity of the iron-doped carbon dot nanozyme in Example 1.
[0025] Figure 5 This is a comparison chart of bananas grown on different days after the iron-doped carbon nanoparticles in Example 1 were processed.
[0026] Figure 6 This is a comparison chart of banana hardness after different days using the iron-doped carbon nanoparticle nanozyme in Example 1. Detailed Implementation
[0027] The present application is further illustrated below with reference to specific embodiments. The following descriptions are merely a few embodiments of the present application and are not intended to limit the present application in any way. Although the present application discloses preferred embodiments as follows, they are not intended to limit the present application. Any modifications or variations made by those skilled in the art without departing from the scope of the technical solution of the present application using the disclosed technical content are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.
[0028] Unless otherwise specified, the raw materials used in the embodiments of this application are all purchased commercially and used directly without any special treatment.
[0029] In the embodiments of this application, the instrument used for ultraviolet absorption spectrum testing is an ultraviolet spectrophotometer, and the testing conditions are a testing range of 200~700nm; The infrared spectrometer was used for the infrared spectroscopy test, with a scanning range of 500-4000 cm⁻¹. -1 .
[0030] Example 1 (1) Grind and mix 0.1 mol of triamic acid and 0.1 mol of m-phenylenediamine, place them in a high-temperature tube furnace, and carry out dehydration and polymerization reaction at 250°C for 4 hours. After cooling to room temperature, grind them into powder to obtain the crude product carbon dots. (2) Dissolve 0.5g of crude carbon dots in 5mL of methanol, sonicate for 20min until completely dissolved, slowly add 50mL of acetonitrile to precipitate, centrifuge and vacuum dry at 60℃ for 5h to obtain purified carbon dots; (3) Dissolve 0.3g of purified carbon dots in 1mL of dimethyl sulfoxide, then add 0.3g of ferric chloride and stir for 0.5h. Slowly add 10mL of water to precipitate, centrifuge and vacuum dry at 65℃ for 8h to obtain iron-doped carbon dot nanozyme with a yield of 71%; (4) Prepare an aqueous solution of iron-doped carbon nanoparticles with a concentration of 1 mg / mL, and stir and dissolve it at a constant temperature of 60°C for 1 h, and then spray it evenly on the surface of bananas.
[0031] Results analysis: Figure 1 This indicates that the absorption spectrum of iron-doped carbon nanoparticle nanozymes extends to the entire visible light region, which is beneficial for generating photogenerated electrons; Figure 2 This indicates that iron-doped carbon nanodot nanozymes contain abundant functional groups such as carboxyl and amino groups, providing diverse active sites, which is beneficial for the doping of metallic iron. Figure 3 This indicates that iron-doped carbon nanoparticles have excellent catalytic oxidation performance, and can rapidly oxidize 3,3',5,5'-tetramethylbenzidine, turning it from colorless to blue, with a distinct characteristic peak at 652 nm. Figure 4This indicates that iron-doped carbon nanodot nanozymes can effectively inhibit the growth of Escherichia coli and Staphylococcus aureus; Figure 5 and Figure 6 The results show that spraying bananas with iron-doped carbon dot nanozyme solution extends their shelf life by about 5 days while maintaining good hardness.
[0032] Example 2 (1) Grind and mix 0.2 mol succinic acid and 0.1 mol p-phenylenediamine, place them in a high-temperature tube furnace, and carry out dehydration and polymerization reaction at 200℃ for 6 hours. After cooling to room temperature, grind them into powder to obtain the crude product carbon dots. (2) Dissolve 0.3g of crude carbon dots in 6mL of methanol, sonicate for 30min until completely dissolved, slowly add 100mL of acetonitrile to precipitate, centrifuge and vacuum dry at 60℃ for 8h to obtain purified carbon dots; (3) Dissolve 0.2g of purified carbon dots in 2mL of ethanol, then add 0.3g of copper chloride and stir for 1h. Slowly add 15mL of dichloromethane to precipitate. After centrifugation and vacuum drying at 40℃ for 2h, copper-doped carbon dot nanozymes are obtained with a yield of 68%. (4) Prepare an aqueous solution of copper-doped carbon dot nanoenzyme with a concentration of 0.5 mg / mL, and stir and dissolve it at a constant temperature of 60°C for 2 hours. Then spray it evenly on the surface of the fruit.
[0033] Example 3 (1) Grind and mix 0.1 mol malonic acid and 0.2 mol o-phenylenediamine, place them in a high-temperature tube furnace, and carry out dehydration and polymerization reaction at 180°C for 2 hours. After cooling to room temperature, grind them into powder to obtain the crude product carbon dots. (2) Dissolve 0.3g of crude carbon dots in 5mL of acetone, sonicate for 20min until completely dissolved, slowly add 30mL of n-hexane to precipitate, centrifuge and vacuum dry at 40℃ for 3h to obtain purified carbon dots; (3) Dissolve 0.1g of purified carbon dots in 1mL of methanol, then add 0.1g of cobalt chloride and stir for 2h. Slowly add 10mL of acetonitrile to precipitate. After centrifugation and vacuum drying at 60℃ for 8h, iron-doped carbon dot nanozymes are obtained with a yield of 65%. (4) Prepare an aqueous solution of iron-doped carbon nanoparticles with a concentration of 2 mg / mL, and stir and dissolve it at a constant temperature of 60°C for 3 hours. Then spray it evenly on the surface of the fruit.
[0034] Example 4 (1) Grind and mix 0.25 mol of triamic acid and 0.1 mol of p-phenylenediamine, place them in a high-temperature tube furnace, and carry out dehydration and polymerization reaction at 200℃ for 8 hours. After cooling to room temperature, grind them into powder to obtain the crude product carbon dots. (2) Dissolve 0.5g of crude carbon dots in 3mL of methanol, sonicate for 30min until completely dissolved, slowly add 30mL of acetonitrile to precipitate, centrifuge and vacuum dry at 60℃ for 3h to obtain purified carbon dots; (3) Dissolve 0.3g of purified carbon dots in 3mL of dimethyl sulfoxide, then add 0.3g of ferric chloride and stir for 2h. Slowly add 10mL of water to precipitate, centrifuge and vacuum dry at 65℃ for 6h to obtain iron-doped carbon dot nanozyme with a yield of 62%; (4) Prepare an aqueous solution of iron-doped carbon nanoparticles with a concentration of 3 mg / mL, and stir and dissolve it at a constant temperature of 60°C for 1 h, and then spray it evenly on the surface of the fruit.
[0035] Example 5 (1) Grind and mix 0.1 mol of triamic acid and 0.1 mol of o-phenylenediamine, place them in a high-temperature tube furnace, and carry out dehydration and polymerization reaction at 230°C for 2 hours. After cooling to room temperature, grind them into powder to obtain the crude product carbon dots. (2) Dissolve 0.5g of crude carbon dots in 3mL of methanol, sonicate for 20min until completely dissolved, slowly add 30mL of acetonitrile to precipitate, centrifuge and vacuum dry at 60℃ for 3h to obtain purified carbon dots; (3) Dissolve 0.15g of purified carbon dots in 3mL of methanol, then add 0.15g of copper chloride and stir for 0.5h. Slowly add 30mL of acetonitrile to precipitate, centrifuge and vacuum dry at 65℃ for 5h to obtain copper-doped carbon dot nanozymes with a yield of 72%. (4) Prepare an aqueous solution of iron-doped carbon nanoparticles with a concentration of 1.5 mg / mL, and stir and dissolve it at a constant temperature of 60°C for 0.5 h, and then spray it evenly on the surface of the fruit.
[0036] Example 6 (1) Grind and mix 0.1 mol succinic acid and 0.1 mol o-phenylenediamine, place them in a high-temperature tube furnace, and carry out dehydration and polymerization reaction at 150°C for 5 hours. After cooling to room temperature, grind them into powder to obtain the crude product carbon dots. (2) Dissolve 0.5g of crude carbon dots in 5mL of methanol, sonicate for 30min until completely dissolved, slowly add 50mL of acetonitrile to precipitate, centrifuge and vacuum dry at 60℃ for 6h to obtain purified carbon dots; (3) Dissolve 0.1g of purified carbon dots in 3mL of dimethyl sulfoxide, then add 0.3g of cobalt chloride and stir for 2h. Slowly add 30mL of water to precipitate, centrifuge and vacuum dry at 65℃ for 8h to obtain cobalt-doped carbon dot nanozyme with a yield of 67%; (4) Prepare an aqueous solution of iron-doped carbon nanoparticles with a concentration of 3 mg / mL, and stir and dissolve it at a constant temperature of 60°C for 3 hours. Then spray it evenly on the surface of the fruit.
[0037] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
Claims
1. A method for preparing a metal-doped carbon dot nanoszyme, characterized in that, The preparation method comprises: (1) adopting a solid phase pyrolysis method to perform dehydration and polymerization reaction on a mixture containing polybasic acid and polyamine to obtain a crude product carbon dot; (2) dissolving the crude product carbon dot in a solvent to obtain a purified carbon dot through reverse precipitation; (3) mixing and dissolving the purified carbon dot with a metal salt to obtain the metal-doped carbon dot nanoscale enzyme through reverse precipitation.
2. The production method according to claim 1, characterized by, In the step (1), the polybasic acid is a polycarboxylic acid; the polycarboxylic acid is at least one selected from tricarballylic acid, succinic acid and malonic acid.
3. The production method according to claim 1, characterized by, The polyamine is at least one selected from m-phenylenediamine, p-phenylenediamine and o-phenylenediamine.
4. The method of claim 1, wherein, The molar ratio of the polybasic acid to the polyamine is 0.5-2:1-6.
5. The preparation method according to claim 1, characterized in that, In the step (1), the pyrolysis temperature is 150-300 ℃, and the time is 1-8 hours.
6. The method of claim 1, wherein, In the step (2), the solvent comprises one of a combination of methanol-acetonitrile, chloroform-toluene and acetone-n-hexane.
7. The preparation method according to claim 1, characterized in that, In the step (3), the metal salt is at least one selected from ferric chloride, copper chloride and cobalt chloride; Preferably, in the step (3), the mass ratio of the carbon dot to the metal salt is 1:0.5-3; Preferably, in the step (3), the solvent used comprises one of a combination of dimethyl sulfoxide-water, ethanol-dichloromethane and methanol-acetonitrile.
8. A metal-doped carbon dot nanoszyme, characterized in that, The metal-doped carbon dot nanoscale enzyme comprises at least one prepared by the preparation method according to any one of claims 1-7.
9. The metal-doped carbon dot nanoscale enzyme according to claim 8 for use in antibacterial preservation.
10. Use according to claim 9, characterized in that, The application method comprises dispersing the metal-doped carbon dot nanoscale enzyme in water, soaking or spraying the antibacterial preservation object to achieve the antibacterial preservation function; Preferably, the concentration of the metal-doped carbon dot nanoscale enzyme after being dispersed in water is 0.1-5 mg / mL.