Taurine carbon dot nano-enzyme with broad-spectrum antioxidant activity as well as preparation method and application of taurine carbon dot nano-enzyme

Abstract

The invention relates to a taurine carbon dot nano-enzyme with broad-spectrum antioxidant activity as well as a preparation method and application of the taurine carbon dot nano-enzyme. The preparation method of the taurine carbon dot nano-enzyme with the broad-spectrum antioxidant activity comprises the following steps: mixing a glucose solution with a taurine solution to obtain a reaction solution, adjusting the pH value of the reaction solution to be alkaline by using alkali, then reacting by adopting a microwave-assisted hydrothermal method, and dialyzing to obtain the taurine carbon dot nano-enzyme with the broad-spectrum antioxidant activity. The taurine carbon dot nano-enzyme with broad-spectrum antioxidant activity is prepared by taking glucose as a carbon source, taurine as a sulfur source and a nitrogen source and water as a solvent through a microwave-assisted hydrothermal method. Compared with the traditional hydrothermal method, the microwave-assisted hydrothermal method disclosed by the invention can be used for rapidly preparing the taurine carbon dot nano-enzyme with uniform size.

Description

Technical Field

[0001] The present invention belongs to the technical field of quantum dot preparation, and specifically relates to taurine carbon dot nanozyme with broad-spectrum antioxidant activity, a preparation method and an application thereof. Background Art

[0002] Reactive oxygen species (ROS) refers to a class of oxygen-containing chemically reactive substances, including superoxide, peroxide, hydroxyl radical and singlet oxygen. As a normal metabolite in the life activities of the body, ROS can play an important role in physiological functions such as anti-inflammatory, antibacterial and tumor inhibition by participating in signal transduction, immune response and regulating gene expression. The level of ROS in animals is precisely regulated by enzymes (oxidases and antioxidant enzymes) and small molecule antioxidants to maintain it at an appropriate level. Low levels of ROS are beneficial to the body. However, under the influence of various environmental stresses or biological factors (for example, ultraviolet rays, heat exposure, inflammation or bacterial infection, etc.), ROS levels will increase sharply. Excessive production of ROS can cause oxidative stress, which in turn induces various chronic and acute diseases. In addition, studies have shown that many diseases such as cardiovascular disease, Alzheimer's disease, autism spectrum disorder, diabetes, sepsis, etc. are related to oxidative stress caused by excessive production of ROS. Therefore, maintaining the homeostasis of ROS in the body is a common means to reduce a series of oxidative damage caused by it.

[0003] With the development trend of customization and refinement of biomedical materials, nanomaterials have gradually become one of the powerful tools for disease prevention, diagnosis and treatment. As a new generation of artificial enzyme simulation, nanozymes have unique enzyme-like properties, can efficiently remove ROS, and are broad-spectrum antioxidant nanozymes. They have the potential to treat inflammatory damage diseases induced by excessive ROS in organisms. Carbon dots (CarbonDots), as a carbon-based material, have a particle size of less than 10nm and are a typical zero-dimensional nanomaterial. Compared with traditional materials, carbon dots have the advantages of low toxicity, good biocompatibility and easy modification. The biocompatibility of carbon dots mainly comes from their carbon core structure, which enables them to exist stably in biological systems. There are a variety of functional groups on the surface of carbon quantum dots, including carbonyl, hydroxyl and carboxyl groups. Based on different enzyme catalytic active sites on the surface, a variety of enzyme activities can be achieved, so they show great application potential in biomedicine, biocatalysis and other fields.

[0004] The invention patent with application publication number CN117985696A discloses an N-doped carbon quantum dot, a preparation method and an application thereof. The N-doped carbon quantum dot is prepared by a hydrothermal synthesis method using ginsenoside, ethylenediamine and water as raw materials. Although the N-doped carbon quantum dot is mentioned for use in scavenging oxygen free radicals, ABTS free radicals, DPPH free radicals and iron ions, the scavenging effect on ABTS free radicals, DPPH free radicals and oxygen free radicals is poor. Summary of the invention

[0005] The first object of the present invention is to provide a taurine carbon dot nanozyme with broad-spectrum antioxidant activity to solve the technical problem that the existing carbon quantum dots with broad-spectrum antioxidant activity have poor scavenging effects when scavenging ABTS free radicals, DPPH free radicals, and oxygen free radicals.

[0006] The second object of the present invention is to provide a method for preparing taurine carbon dot nanozyme with broad-spectrum antioxidant activity.

[0007] The third object of the present invention is the application of taurine carbon dot nanozymes with broad-spectrum antioxidant activity.

[0008] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0009] The preparation method of taurine carbon dot nanozyme with broad-spectrum antioxidant activity comprises the following steps: mixing a glucose solution and a taurine solution to obtain a reaction solution, adjusting the pH of the reaction solution to alkaline with alkali, and then reacting and dialyzing the reaction solution using a microwave-assisted hydrothermal method.

[0010] Furthermore, the molar ratio of the glucose to the taurine is 1:1 to 3:1.

[0011] Furthermore, the alkali is a sodium hydroxide solution, and the pH is 9-11.

[0012] Furthermore, the microwave power of the microwave-assisted hydrothermal method is 400-800W; the reaction temperature is 140-160°C; and the reaction time is 0.5-1h.

[0013] Furthermore, the dialysis method is to use a dialysis bag with a molecular weight cutoff of 500 to 1000 Da for 24 to 36 hours.

[0014] The taurine carbon dot nanozyme with broad-spectrum antioxidant activity is prepared by using the above-mentioned method for preparing the taurine carbon dot nanozyme with broad-spectrum antioxidant activity.

[0015] Application of taurine carbon dot nanozymes with broad-spectrum antioxidant activity in scavenging free radicals.

[0016] Furthermore, the free radicals include DPPH superoxide free radicals, ABTS superoxide free radicals, superoxide free radicals, hydroxyl free radicals, and singlet oxygen superoxide free radicals.

[0017] Furthermore, the average particle size of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity is 2 to 3 nm.

[0018] Beneficial effects of the present invention:

[0019] The present invention uses glucose as a carbon source, taurine as a sulfur source and a nitrogen source, and water as a solvent to prepare taurine carbon dot nanozymes with broad-spectrum antioxidant activity through a microwave-assisted hydrothermal method. Compared with the traditional hydrothermal method, the microwave-assisted hydrothermal method of the present invention can quickly prepare taurine carbon dot nanozymes with uniform size.

[0020] The raw materials of the present invention are glucose and taurine, and on the basis of reducing the toxicity of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity, efficient removal of active oxygen species is achieved, and the nanozyme has broad-spectrum antioxidant activity.

[0021] The taurine carbon dot nanozyme with broad-spectrum antioxidant activity of the present invention is doped with sulfur and nitrogen elements, providing different active sites for scavenging reactive oxygen free radicals. In the actual process of scavenging reactive oxygen free radicals, compared with a single site doped with only nitrogen element or only sulfur element, the co-doping of sulfur element and nitrogen element provides more matching adsorption and reaction sites for different reactive oxygen free radicals, further improving the efficiency of scavenging reactive oxygen free radicals on the basis of having broad-spectrum antioxidant properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Characterization diagram of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity in Example 1, wherein (a) is a transmission electron microscopy image and (b) is a particle size image;

[0023] Figure 2 The UV-visible absorption spectrum and photoluminescence spectrum of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity in Example 1;

[0024] Figure 3 The XPS spectra of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity in Example 1, wherein (a) is a fine spectrum of the C1s energy level, (b) is a fine spectrum of the N1s energy level, and (c) is a fine spectrum of the S2p energy level;

[0025] Figure 4 The taurine carbon dot nanozyme with broad-spectrum antioxidant activity in Example 1 is shown in Figure 1. +· Scavenging activity and DPPH · Cleared activity diagram, where (a) is for ABTS+· The scavenging activity diagram of (b) is for DPPH · The removal activity diagram of

[0026] Figure 5 These are the scavenging activity diagrams of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity in Example 1 against reactive oxygen free radicals, wherein (a) is the scavenging activity diagram for hydroxyl free radicals, (b) is the scavenging activity diagram for superoxide free radicals, and (c) is the scavenging activity diagram for singlet oxygen free radicals. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the embodiments of the present invention and the accompanying drawings.

[0028] Example 1

[0029] The preparation method of taurine carbon dot nanozyme with broad-spectrum antioxidant activity of Example 1 comprises the following steps: adding 5 mL of 100 mM taurine aqueous solution to 5 mL of 100 mM glucose aqueous solution, magnetically stirring for 30 min to fully mix the taurine aqueous solution and the glucose aqueous solution to obtain a reaction solution, slowly adding 1 M sodium hydroxide solution to the reaction solution under magnetic stirring, adjusting the pH to 11, and then transferring the pH-adjusted reaction solution to a microwave digestion tank, reacting at 400 W microwave power and 160 ° C for 0.5 h, and dialyzing in a 1000 Da dialysis bag for 24 h after the reaction is completed.

[0030] Example 2

[0031] The preparation method of taurine carbon dot nanozyme with broad-spectrum antioxidant activity of Example 2 comprises the following steps: adding 2.5 mL of 100 mM taurine aqueous solution to 7.5 mL of 100 mM glucose aqueous solution, magnetically stirring for 30 min to fully mix the taurine aqueous solution and the glucose aqueous solution to obtain a reaction solution, slowly adding 1 M sodium hydroxide solution to the reaction solution under magnetic stirring, adjusting the pH to 11, and then transferring the pH-adjusted reaction solution to a microwave digestion tank, reacting at 400 W microwave power and 160 ° C for 0.5 h, and dialyzing in a 1000 Da dialysis bag for 24 h after the reaction is completed.

[0032] Example 3

[0033] The preparation method of taurine carbon dot nanozyme with broad-spectrum antioxidant activity of Example 3 includes the following steps: adding 3.3 mL of 100 mM taurine aqueous solution to 6.6 mL of 100 mM glucose aqueous solution, magnetically stirring for 30 min to fully mix the taurine aqueous solution and the glucose aqueous solution to obtain a reaction solution, slowly adding 1 M sodium hydroxide solution to the reaction solution under magnetic stirring, adjusting the pH to 11, and then transferring the pH-adjusted reaction solution to a microwave digestion tank, reacting at 400 W microwave power and 160 ° C for 0.5 h, and dialyzing in a 1000 Da dialysis bag for 24 h after the reaction is completed.

[0034] Example 4

[0035] Add 5 mL of 100 mM taurine aqueous solution to 5 mL of 100 mM glucose aqueous solution, stir magnetically for 30 min to fully mix the taurine aqueous solution and the glucose aqueous solution to obtain a reaction solution, slowly add 1 M sodium hydroxide solution to the reaction solution under magnetic stirring, adjust the pH to 11, then transfer the pH-adjusted reaction solution to a microwave digestion tank, react at 400 W microwave power and 140° C. for 1 h, and dialyze in a 1000 Da dialysis bag for 24 h after the reaction is completed.

[0036] Example 5

[0037] Add 5 mL of 100 mM taurine aqueous solution to 5 mL of 100 mM glucose aqueous solution, and stir magnetically for 30 min to fully mix the taurine aqueous solution and the glucose aqueous solution to obtain a reaction solution. Slowly add 1 M sodium hydroxide solution to the reaction solution under magnetic stirring to adjust the pH to 9. Then transfer the pH-adjusted reaction solution to a microwave digestion tank, react at 800 W microwave power and 160° C. for 0.5 h, and dialyze in a 1000 Da dialysis bag for 24 h after the reaction is completed.

[0038] Example 6

[0039] Add 5 mL of 100 mM taurine aqueous solution to 5 mL of 100 mM glucose aqueous solution, stir magnetically for 30 min to fully mix the taurine aqueous solution and the glucose aqueous solution to obtain a reaction solution, slowly drop a 1 M sodium hydroxide solution into the reaction solution under magnetic stirring, adjust the pH to 11, then transfer the pH-adjusted reaction solution to a microwave digestion tank, react at 600 W microwave power and 150° C. for 0.75 h, and dialyze in a 1000 Da dialysis bag for 36 h after the reaction is completed.

[0040] Example 7

[0041] Add 5 mL of 100 mM taurine aqueous solution to 5 mL of 100 mM glucose aqueous solution, stir magnetically for 30 min to fully mix the taurine aqueous solution and the glucose aqueous solution to obtain a reaction solution, slowly add 1 M sodium hydroxide solution to the reaction solution under magnetic stirring, adjust the pH to 10, then transfer the pH-adjusted reaction solution to a microwave digestion tank, react at 400 W microwave power and 160° C. for 1 h, and dialyze in a 500 Da dialysis bag for 24 h after the reaction is completed.

[0042] Comparative Example 1

[0043] The preparation method of the nanozyme of Comparative Example 1 includes the following steps: slowly adding 1M sodium hydroxide solution to 10mL of 100mM glucose aqueous solution, adjusting the pH to 11, then transferring the pH-adjusted glucose aqueous solution to a microwave digestion tank, reacting at 400W microwave power and 160°C for 0.5h, and dialyzing in a 1000Da dialysis bag for 24h after the reaction is completed.

[0044] from Figure 1 It can be seen that the size of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity in Example 1 is 2-3 nm and has good uniformity. Figure 3 (b) It can be seen that the prepared taurine carbon dot nanozymes with broad-spectrum antioxidant activity contain different forms of nitrogen species, including graphitic nitrogen and pyrrolic nitrogen. Figure 3 (c) It can be seen that sulfur exists in the form of C-SOx bonds. Figure 3 It can be seen that taurine reacts fully with glucose, and sulfur and nitrogen are co-doped on the carbon quantum dots. Figure 4 (a) and Figure 4 As can be seen in (b), the prepared taurine carbon dot nanozyme with broad-spectrum antioxidant activity has an antioxidant effect on ABTS +· With DPPH · All of them showed efficient scavenging activity. With the increase of the concentration of taurine carbon dot nanozymes with broad-spectrum antioxidant activity, the +· With DPPH · The scavenging activity of Figure 5 It can be seen that taurine carbon dot nanozymes with broad-spectrum antioxidant activity have a strong anti-oxidative effect on hydroxyl radicals (·OH) and superoxide radicals (O2 ·- ), singlet oxygen radicals ( 1 O2) have scavenging activity, and the taurine carbon dot nanozyme with broad-spectrum antioxidant activity prepared by the present invention has high-efficiency spectrum antioxidant activity.

[0045] The clearance rates of the nanozymes of Examples 1-3 and Comparative Example 1 for different substrates are shown in Table 1, and the doping amounts of nitrogen and sulfur elements in the carbon quantum dots of Examples 1-3 and Comparative Example 1 are shown in Table 2.

[0046] Table 1 Removal rate of carbon quantum dots of Examples 1-3 and Comparative Example 1 on different substrates

[0047]

[0048] Table 2 Doping amount of nitrogen and sulfur elements in carbon quantum dots of Examples 1-3 and Comparative Example 1

[0049]

[0050] It can be seen from Table 1 and Table 2 that when the concentration of the nanozymes of Examples 1-3 and Comparative Example 1 is 50 μg / mL and the reaction time is 5 min, the nanozyme of Example 1 has the highest clearance rate for each substrate. When the molar ratio of taurine to glucose is 1:1, the doping amount of nitrogen and sulfur elements is the highest, and at this time, the clearance rate of DPPH · ,ABTS +· , OH, O2 ·- , 1 O2 has the highest clearance rate.

Claims

1. A method for preparing taurine carbon dot nanozymes with broad-spectrum antioxidant activity, characterized in that: The following steps are involved: The glucose solution and the taurine solution are mixed to obtain a reaction solution, the pH of the reaction solution is adjusted to alkaline with alkali, and then a microwave-assisted hydrothermal method is used for reaction and dialyzed to obtain the product.

2. The method for preparing taurine carbon dot nanozyme with broad-spectrum antioxidant activity according to claim 1, characterized in that: The molar ratio of the glucose to the taurine is 1:1 to 3:

1.

3. The method for preparing taurine carbon dot nanozyme with broad-spectrum antioxidant activity according to claim 1, characterized in that: The alkali is sodium hydroxide solution, and the pH is 9-11.

4. The method for preparing taurine carbon dot nanozyme with broad-spectrum antioxidant activity according to claim 1, characterized in that: The microwave power of the microwave-assisted hydrothermal method is 400-800W; the reaction temperature is 140-160°C; and the reaction time is 0.5-1h.

5. The method for preparing taurine carbon dot nanozyme with broad-spectrum antioxidant activity according to claim 1, characterized in that: The dialysis method is to use a dialysis bag with a molecular weight cutoff of 500 to 1000 Da for 24 to 36 hours.

6. Taurine carbon dot nanozyme with broad-spectrum antioxidant activity, characterized in that: The taurine carbon dot nanozyme with broad-spectrum antioxidant activity is prepared by the preparation method of any one of claims 1 to 5.

7. Use of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity as claimed in claim 6 in scavenging free radicals.

8. The use of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity according to claim 7, characterized in that: The free radicals include DPPH free radical, ABTS free radical, superoxide free radical, hydroxyl free radical and singlet oxygen free radical.

9. The use of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity according to claim 7, characterized in that: The average particle size of the taurine carbon dot nanozyme with broad-spectrum antioxidant activity is 2 to 3 nm.

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