High-yield preparation method and application of carbon quantum dots

Abstract

The invention provides a high-yield preparation method and application of carbon quantum dots, and is characterized in that the high-yield preparation method comprises the following steps: adding catechin into deionized water, and shaking and uniformly mixing to obtain a catechin solution; and carrying out a hydrothermal reaction on the solution, cooling to room temperature after the reaction is completed, then carrying out centrifugation and filtration, and finally carrying out freeze drying on the filtrate to obtain the carbon quantum dots. The invention provides the method for preparing the carbon quantum dots with high yield, and the carbon quantum dots have the advantages of high yield, few byproducts, excellent dispersity and water solubility, low cost and easiness in large-scale production, and can be applied to treatment of gastric ulcer.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon nanomaterial preparation, and specifically relates to a high-yield preparation method and application of carbon quantum dots. Background Art

[0002] Gastric ulcer refers to the damage of the gastric mucosa under the action of gastric acid and pepsin, forming local defects or ulcers. Common causes include Helicobacter pylori infection, long-term use of non-steroidal anti-inflammatory drugs, excessive gastric acid secretion, weakened gastric mucosal protection function, and bad living habits (such as irregular diet, long-term alcohol consumption, smoking, etc.). Patients often show symptoms such as upper abdominal pain, acid reflux, belching, loss of appetite, etc. In severe cases, it may cause complications such as bleeding, perforation or pyloric obstruction, affecting the quality of life.

[0003] The treatment of gastric ulcer mainly relies on drugs, such as proton pump inhibitors and potassium ion competitive acid blockers, to inhibit gastric acid secretion, promote ulcer healing, and eradicate Helicobacter pylori. However, these methods have problems such as poor drug tolerance, side effects, and Helicobacter pylori drug resistance. Carbon quantum dots show advantages in the treatment of gastric ulcer due to their good biocompatibility, low toxicity, and anti-inflammatory and antioxidant properties, and can effectively protect the gastric mucosa. However, the current synthesis process of carbon quantum dots is relatively complex and the yield is low, which limits their wide application. Based on this, developing a simple and high-yield synthesis process of carbon quantum dots is of great significance for the treatment of gastric ulcer.

[0004] Therefore, the present invention proposes a high-yield preparation method and application of carbon quantum dots. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a high-yield preparation method of carbon quantum dots, which is characterized by including the following steps:

[0006] S1. Add catechin to deionized water and obtain a catechin solution by shaking and mixing evenly;

[0007] S2. Perform a hydrothermal reaction on the catechin solution, cool it to room temperature after the reaction is completed, then perform centrifugation and filtration, and finally freeze-dry the obtained filtrate to obtain Ct-CQDs.

[0008] Further, in S1, the ratio of catechin to water is 0.1 - 5:30 g / mL, preferably 0.8 - 1.2:30 g / mL.

[0009] Further, the concentration of catechin in S1 is 0.003 - 0.16 g / mL, preferably 0.028 - 0.048 g / mL.

[0010] Further, in S2, the temperature of the hydrothermal reaction is 100 - 280 °C, and the time is 1 - 8 h; the hydrothermal reaction is carried out in a polytetrafluoroethylene-lined hydrothermal reactor.

[0011] Further, in S2, the rotation speed of centrifugation is 10000 r / min, and the time is 5 ± 1 min.

[0012] Further, in S2, the filtration is carried out using a water phase filter membrane with a pore size of 0.22 μm.

[0013] Further, in S2, the temperature of freeze-drying is -10 to -90 °C.

[0014] The present invention further protects the application of the above carbon quantum dots in the treatment of gastric ulcer.

[0015] The beneficial effects of the present invention are as follows:

[0016] The present invention provides a high-yield preparation method of carbon quantum dots. By controlling the temperature, time of the hydrothermal reaction and the ratio of catechin to deionized water, the yield of carbon quantum dots is improved; the carbon quantum dots prepared by this method have a high yield, few by-products, excellent dispersibility and water solubility, and the process of the present invention is simple, the required instruments and equipment are simple, easy to operate, the process conditions are easy to achieve, the production cost is low, and the large-scale production of carbon quantum dots and the application in the treatment of gastric ulcer can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present invention.

[0018] Figure 1 It is the transmission electron microscope picture of Ct-CQDs prepared in Example 1.

[0019] Figure 2 It is the lattice spacing diagram of Ct-CQDs prepared in Example 1.

[0020] Figure 3 It is the particle size distribution statistical chart of Ct-CQDs prepared in Example 1.

[0021] Figure 4 It is the effect picture of Ct-CQDs prepared in Example 1 after treating gastric ulcer.

[0022] Figure 5 It is the HE staining picture of Ct-CQDs prepared in Example 1 after treating gastric ulcer. Detailed implementation manners

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] Embodiment 1

[0025] This embodiment provides a preparation method of carbon quantum dots, including:

[0026] (1) Add 1 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0027] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 180 °C for 3 h, naturally cool to room temperature, centrifuge for 5 min at a rotation speed of 10,000 r / min, and collect the filtrate after filtering with a 0.22 μm filter membrane;

[0028] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 98%.

[0029] Figure 1 FIG. is a transmission electron microscope picture of the carbon quantum dots prepared in Embodiment 1. It can be seen from the figure that the particle size of the carbon quantum dots is evenly distributed.

[0030] Figure 2 FIG. is the lattice spacing of the transmission electron microscope picture of the carbon quantum dots prepared in Embodiment 1. It can be seen from the figure that the crystal plane spacing is 0.22 nm, corresponding to the graphite (100) crystal plane.

[0031] Figure 3 FIG. is a statistical chart of the particle size distribution of the carbon quantum dots prepared in Embodiment 1. It can be seen from the figure that the average particle size of the obtained carbon quantum dots is 2.61 nm.

[0032] Embodiment 2

[0033] This embodiment provides a preparation method of carbon quantum dots, including:

[0034] (1) Add 0.5 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0035] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 180 °C for 3 h, naturally cool to room temperature, centrifuge at a speed of 10,000 r / min for 5 min, and filter with a 0.22 μm filter membrane, then collect the filtrate;

[0036] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 88%.

[0037] Example 3

[0038] This example provides a method for preparing carbon quantum dots, including:

[0039] (1) Add 2 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0040] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 180 °C for 3 h, naturally cool to room temperature, centrifuge at a speed of 10,000 r / min for 5 min, and filter with a 0.22 μm filter membrane, then collect the filtrate;

[0041] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 65%.

[0042] Example 4

[0043] This example provides a method for preparing carbon quantum dots, including:

[0044] (1) Add 1 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0045] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 160 °C for 3 h, naturally cool to room temperature, centrifuge at a speed of 10,000 r / min for 5 min, and filter with a 0.22 μm filter membrane, then collect the filtrate;

[0046] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 55%.

[0047] Example 5

[0048] This example provides a method for preparing carbon quantum dots, including:

[0049] (1) Add 1 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0050] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 200 °C for 3 h, naturally cool to room temperature, centrifuge for 5 min at a rotation speed of 10,000 r / min, and filter with a 0.22-μm filter membrane, then collect the filtrate;

[0051] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 29%.

[0052] Example 6

[0053] This example provides a method for preparing carbon quantum dots, including:

[0054] (1) Add 1 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0055] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 220 °C for 3 h, naturally cool to room temperature, centrifuge for 5 min at a rotation speed of 10,000 r / min, and filter with a 0.22-μm filter membrane, then collect the filtrate;

[0056] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 25%.

[0057] Example 7

[0058] This example provides a method for preparing carbon quantum dots, including:

[0059] (1) Add 1 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0060] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 180 °C for 2 h, naturally cool to room temperature, centrifuge for 5 min at a rotation speed of 10,000 r / min, and filter with a 0.22-μm filter membrane, then collect the filtrate;

[0061] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 76%.

[0062] Example 8

[0063] This example provides a method for preparing carbon quantum dots, including:

[0064] (1) Add 1 g of catechin to 30 mL of deionized water, shake and mix evenly to obtain a milky white catechin solution;

[0065] (2) Transfer the catechin solution obtained in step (1) to a reaction kettle, seal it, react at 180 °C for 4 h, naturally cool to room temperature, centrifuge at a speed of 10,000 r / min for 5 min, and filter with a 0.22 μm filter membrane, then collect the filtrate;

[0066] (3) Freeze-dry the filtrate obtained in step (2) at -50 °C for 24 h to obtain carbon quantum dots, and the yield is 54%.

[0067] The above results show that the prepared carbon quantum dots have a very high yield.

[0068] Example 9

[0069] Taking the Ct-CQDs prepared in Example 1 as an example, tests are carried out to verify the performance of the Ct-CQDs prepared by the present invention.

[0070] Use a transmission electron microscope to observe the morphology of Ct-CQDs, and the results are as Figure 1 shown.

[0071] It can be seen from Figure 1 that Ct-CQDs are evenly distributed and approximately circular.

[0072] It can be seen from Figure 2 that Ct-CQDs have good crystallinity, with obvious lattice fringes, and the measured interplanar spacing is about 0.22 nm, corresponding to the (101) crystal plane of carbon.

[0073] It can be seen from Figure 3 that the particle size of Ct-CQDs is mainly between 2.61 nm.

[0074] Detect the effect of Ct-CQDs in treating gastric ulcers through an animal gastric ulcer model.

[0075] First, configure the prepared Ct-CQDs into carbon quantum dot solutions with two different concentrations of 5 μg / ml and 15 μg / ml with normal saline.

[0076] Then divide the rats into groups, with 6 rats in each group, a total of 4 groups. They are the control group, the model group, the 5 μg / ml Ct-CQDs experimental group, and the 15 μg / ml Ct-CQDs experimental group.

[0077] Control group: Intragastric administration with normal saline throughout the process.

[0078] Model group: Intragastric administration with normal saline for the first 7 days, and intragastric administration with 95% alcohol on the 8th day to create a gastric ulcer model.

[0079] 5 μg / ml Ct-CQDs experimental group: For the first 7 days, intragastric administration was performed with a 5 μg / ml Ct-CQDs solution, and on the 8th day, intragastric administration was performed with 95% alcohol to create a gastric ulcer model.

[0080] 15 μg / ml Ct-CQDs experimental group: For the first 7 days, intragastric administration was performed with a 15 μg / ml Ct-CQDs solution, and on the 8th day, intragastric administration was performed with 95% alcohol to create a gastric ulcer model.

[0081] One hour after intragastric administration of 95% alcohol, all rats were sacrificed, the stomachs of the rats were removed, photographed and preserved, then fixed with paraformaldehyde and embedded in paraffin. The specimen sections were stained with HE.

[0082] From Figure 4 It can be seen that the gastric tissue of the rats in the control group was intact without bleeding. However, a large number of blood streaks and blood spots appeared in the stomachs of the rats in the model group, indicating that the gastric ulcer model was successfully established. There were a certain amount of blood streaks and blood spots in the stomachs of the rats in the 5 μg / ml Ct-CQDs experimental group, while there were almost no blood streaks and blood spots in the stomachs of the rats in the 15 μg / ml Ct-CQDs experimental group. It shows that Ct-CQDs can effectively treat gastric ulcers, and the therapeutic effect of 15 μg / ml Ct-CQDs is the best.

[0083] From Figure 5 It can be seen from the HE staining map of the stomach of the rats in the control group that the glandular tissues in the tissue mucosa layer were arranged neatly, and the mucosa layer, submucosa layer and muscular layer were intact without obvious inflammatory cell infiltration. On the contrary, in the HE staining map of the model group, the gastric mucosa glandular structure was severely damaged, there was obvious glandular cavity dilation, and part of the mucosa layer structure disappeared, and a large number of inflammatory cells infiltrated between the glandular cavities and glandular cells in the lamina propria. It can be seen from the HE staining map of the 5 μg / ml Ct-CQDs experimental group that there was also a certain degree of glandular cavity dilation and part of the mucosa layer structure disappeared. However, there was almost no glandular cavity dilation and disappearance of the mucosa layer structure in the HE staining map of the 15 μg / ml Ct-CQDs experimental group. It was basically the same as the control group, indicating that 15 μg / ml Ct-CQDs can effectively treat gastric ulcers.

Claims

1. A method for preparing carbon quantum dots with high yield, characterized in that, It includes the following steps: S1. Add catechin into deionized water and obtain a catechin solution by shaking and mixing evenly; S2. Carry out a hydrothermal reaction on the catechin solution. After the reaction is completed, cool it to room temperature, then carry out centrifugation and filtration. Finally, freeze-dry the obtained filtrate to obtain Ct-CQDs.

2. The high-yield preparation method of carbon quantum dots according to claim 1, characterized in that, In S1, the ratio of catechin to water is 0.1-5:30 g / mL, preferably 0.8-1.2:30 g / mL.

3. A high-yield preparation method of carbon quantum dots according to claim 1, characterized in that In S1, the concentration of catechin is 0.003-0.16 g / mL, preferably 0.028-0.048 g / mL.

4. A high-yield preparation method of carbon quantum dots according to claim 1, characterized in that, In S2, the temperature of the hydrothermal reaction is 100-280 °C and the time is 1-8 h; the hydrothermal reaction is carried out in a polytetrafluoroethylene-lined hydrothermal reaction kettle.

5. A high-yield preparation method of carbon quantum dots according to claim 1, characterized in that, In S2, the rotation speed of centrifugation is 10000 r / min and the time is 5±1 min.

6. A high-yield preparation method of carbon quantum dots according to claim 1, characterized in that, In S2, filtration is carried out using a water phase filter membrane with a pore size of 0.22 um.

7. A high-yield preparation method of carbon quantum dots according to claim 1, characterized in that In S2, the temperature of freeze-drying is -10--90 °C.

8. Application of the carbon quantum dots as described in claims 1-7 in the treatment of gastric ulcer.

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