A carbon dot derived from a traditional Chinese medicine composition, a preparation method therefor, and use thereof

Abstract

This invention discloses a carbon dot derived from a traditional Chinese medicine composition, its preparation method, and its applications. The carbon dot is obtained from the residue of Xuefu Zhuyu Decoction as raw material through extraction, high-pressure reactor reaction, dialysis, and freeze-drying. The carbon dot of this invention exhibits high water solubility, low toxicity, and high selectivity for ferric ions, making it suitable for sensing ferric ions in aqueous solutions and within cells. It also possesses high fluorescence stability, making it suitable for fluorescent anti-counterfeiting applications. Furthermore, it achieves a 91% degradation rate of indigo carmine under sunlight for 5 hours in photocatalytic degradation, making it suitable for photocatalytic degradation of organic dyes. Simultaneously, the carbon dot of this invention is prepared from waste traditional Chinese medicine residue, demonstrating significant environmental and economic benefits and possessing great application potential in industrial production.

Description

Technical Field

[0001] This invention belongs to the field of traditional Chinese medicine technology, and relates to a carbon dot source of a traditional Chinese medicine composition, its preparation method, and its application. Background Technology

[0002] Millions of tons of traditional Chinese medicine (TCM) residue are generated annually in China as a form of biomass. After decoction, it is typically treated as waste through incineration, landfill, or fixed-area dumping, causing severe environmental pollution. Therefore, the proper treatment of TCM residue is crucial. Currently, the cost of treating one ton of residue using a dedicated incinerator is several thousand yuan. Such high costs urgently necessitate the development of new methods to address this issue. Because discarded TCM residue contains large amounts of cellulose, polysaccharides, and lignin, it is an important source of carbon materials. Simply incinerating it results in a huge waste of resources. Converting the residue into high-value-added carbon materials satisfies the principles of harmlessness, reduction, and resource recovery, bringing significant economic benefits to society.

[0003] In recent years, carbon dots, as a novel carbon material, have become well-known among researchers due to their small particle size, high fluorescence stability, tunable emission spectrum, easy surface functionalization, low toxicity, and good biocompatibility. They hold broad application prospects in photocatalysis, bioimaging, drug delivery, fluorescence sensing, and optoelectronic devices. Particularly in the field of fluorescence sensing, carbon dots can be used to construct novel fluorescent probes for the determination of important metals, small molecules, and macromolecules. According to literature reports, many biomass sources have been used to synthesize carbon dots, including orange peel, rice husk, honey, bananas, black tea, watermelon, and mung beans. However, carbon dots derived from traditional Chinese medicine (TCM) residues are rarely reported. TCM residues are multi-component mixtures that can achieve multi-element (S, P) self-doping. As photocatalysts, they provide more catalytic sites and exhibit better catalytic activity compared to carbon dots prepared from simple orange peel or watermelon residues. Different compositions of TCM residues result in carbon dots with different surface active groups, potentially leading to variations in their response to metal ions and photocatalytic activity. Therefore, exploring the physicochemical properties of carbon dots prepared from waste residues of different TCM formulas is essential. To our knowledge, carbon dots prepared from pharmaceutical residues are generally used for ion detection and fluorescent anti-counterfeiting, but there are no reports to date on photocatalytic degradation of dyes.

[0004] Iron, as one of the most important metals in biological systems, is indispensable to all living systems and is widely distributed in the environment and organisms. Within organisms, iron ions play a crucial role in many physiological processes, such as cell metabolism, oxygen transport, enzymatic reactions, and protein transport. Iron deficiency or excessive accumulation can cause various health problems in organisms, such as heart disease, cancer, anemia, and other organ dysfunctions. Therefore, many analytical methods are used to detect target metal ions, such as atomic absorption spectrometry (ABS), spectrophotometry, voltammetry, inductively coupled plasma mass spectrometry (ICP-MS), and fluorescence sensing. Among all these methods, fluorescence sensing has a significant advantage in the detection of trace metal ion concentrations due to its convenience, rapid response, effective selectivity, and high sensitivity. Carbon dots, as a novel type of fluorescent probe, can be used to detect iron ions because their surface functional groups can specifically complex with metal ions, resulting in a significant quenching of their fluorescence intensity.

[0005] For valuable items and important documents, anti-counterfeiting measures are crucial to prevent counterfeiting and resulting economic losses. Carbon dots are a type of photoluminescent nanomaterial that emits bright fluorescence when excited by light of a specific wavelength. When used as fluorescent ink on security paper, they emit bright blue fluorescence under ultraviolet light at 254nm, making them highly effective for anti-counterfeiting applications.

[0006] With the development of chemical engineering, many organic compounds have been artificially synthesized, such as pesticides, organic dyes, and antibiotics. While these substances improve our lives, they also cause environmental pollution. Therefore, the degradation of these small organic molecules is a problem we need to consider. Photocatalysis offers a solution for the degradation of small organic molecules. Photosensitizers generate reactive oxygen species (ROS) under sunlight, and these highly reactive ROS oxidize and degrade the small organic molecules into carbon dioxide and water. Carbon dots, as photosensitizers, possess excellent photogenerated electron activity. By adjusting the band structure, they can enhance the ability to generate ROS, making carbon dots a promising candidate for application in photocatalysis. Summary of the Invention

[0007] The technical problem to be solved by this invention is to overcome the technical problems in the prior art and provide a carbon dot derived from a traditional Chinese medicine composition, its preparation method and application. The carbon dot of this invention has high water solubility, low toxicity, and high selectivity for ferric ions, and can be applied to the sensing of ferric ions in aqueous solutions and cells; it has high fluorescence stability and can be applied to fluorescent anti-counterfeiting; it can be used for photocatalytic degradation of indigo carmine with a degradation rate of 91% under sunlight for 5 hours, and can be applied to the photocatalytic degradation of organic dyes; at the same time, the carbon dot of this invention is prepared from waste traditional Chinese medicine residue, which has significant environmental and economic benefits and has great application prospects in industrial production.

[0008] To solve the above-mentioned technical problems, the present invention provides a carbon dot derived from a traditional Chinese medicine composition. The carbon dot is obtained by using the residue of Xuefu Zhuyu Decoction as raw material, through extraction, reaction in a high-pressure reactor, dialysis, and freeze-drying.

[0009] The carbon dots from the above-mentioned Chinese medicine composition are further derived from the Xuefu Zhuyu Decoction residue, which is obtained by decocting peach kernel, safflower, angelica, rehmannia root, achyranthes root, chuanxiong rhizome, platycodon root, red peony root, immature bitter orange peel, licorice root, and bupleurum root twice in water and then drying it.

[0010] Based on a general technical concept, the present invention also provides a method for preparing carbon dots from the above-mentioned traditional Chinese medicine composition, the preparation method comprising the following steps:

[0011] S1. Extract the Xuefu Zhuyu Decoction residue with ethanol at high temperature to obtain an extract;

[0012] S2. The extract is transferred to a high-pressure reactor lined with polytetrafluoroethylene, boric acid is added, and the reaction is carried out at 200°C to obtain a reaction solution.

[0013] S3. The reaction solution was placed into a 1000 Da biodialysis bag for dialysis. The solution in the dialysis bag was collected and freeze-dried to obtain carbon dots.

[0014] In the above preparation method, the high-temperature extraction in S1 specifically refers to extraction at 75°C for 2-3 hours; the ethanol is anhydrous ethanol.

[0015] The preparation method described above, further, wherein S2 specifically comprises:

[0016] S2-1. After filtering the extract, transfer it to a high-pressure reactor lined with polytetrafluoroethylene, add boric acid, and react at 200°C for 8 hours.

[0017] S2-2. After the high-pressure reactor cools down naturally, remove excess ethanol by vacuum distillation; add water and sonicate to resuspend, then filter and collect the filtrate.

[0018] Based on a general technical concept, the present invention also provides an application of carbon dots derived from the aforementioned traditional Chinese medicine composition in the detection of ferric ions in water.

[0019] Based on a general technical concept, the present invention also provides an application of carbon dots derived from the aforementioned traditional Chinese medicine composition in detecting intracellular ferric ion overload.

[0020] Based on a general technical concept, the present invention also provides an application of carbon dots derived from the aforementioned traditional Chinese medicine composition in fluorescent anti-counterfeiting and information encryption.

[0021] Based on a general technical concept, the present invention also provides the application of carbon dots derived from the aforementioned traditional Chinese medicine composition in the photocatalytic degradation of organic dyes, pesticides and antibiotics.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] (1) This invention provides a carbon dot derived from a traditional Chinese medicine composition, which is prepared using waste traditional Chinese medicine residue as raw material. It fully follows the idea of ​​waste utilization, which not only satisfies the harmless treatment of the residue, but also uses inexpensive raw materials to prepare a fluorescent probe with high selectivity for ferric ions, which has significant environmental and economic effects.

[0024] (2) The present invention provides a method for preparing carbon dots from traditional Chinese medicine compositions. The carbon dots prepared according to the method of the present invention have high water solubility, low toxicity and high fluorescence stability. They have certain application value in drug loading, bioimaging, fluorescent anti-counterfeiting and degradation of organic small molecule dyes. At the same time, the carbon dots have high selectivity for ferric ions and can be applied to the sensing of ferric ions in aqueous solutions and cells.

[0025] (3) This invention provides an application of carbon dots derived from traditional Chinese medicine compositions in the detection of ferric ions in water. Using traditional Chinese medicine residue as raw material, carbon dots are constructed by doping them with boron. They have good selectivity for ferric ions and can be applied to the sensing of intracellular iron ions.

[0026] (4) The present invention also provides an application of carbon dots derived from the traditional Chinese medicine composition in fluorescent anti-counterfeiting and information encryption. Carbon dots are a type of photoluminescent nanomaterial that can emit bright fluorescence when excited by excitation light of a specific wavelength. When written on security paper as fluorescent ink, they can emit bright blue fluorescence when excited by ultraviolet light at 254nm. Therefore, they have a good application in anti-counterfeiting.

[0027] (5) The present invention also provides an application of carbon dots derived from the traditional Chinese medicine composition in the photocatalytic degradation of organic dyes, pesticides and antibiotics; carbon dots, as photosensitizers, have good photogenerated electron activity, regulate band structure and improve the ability to generate reactive oxygen species, and carbon dots will have good applications in the field of photocatalysis.

[0028] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0029] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0030] Figure 1 This is a flowchart illustrating the preparation process of carbon dots in Example 1 of the present invention.

[0031] Figure 2 This is a transmission electron microscope and fluorescence characterization result of carbon dots in Example 1 of Experiment 1 of the present invention.

[0032] Figure 3 This is the infrared spectral characterization result of carbon dots in Example 1 of Experiment 1 of the present invention.

[0033] Figure 4 This is a photoelectron spectroscopy characterization result of carbon dots in Example 1 of Experiment 1 of the present invention.

[0034] Figure 5 This is a fluorescence spectrum of the carbon dots in Example 1 under different metal ions in Experiment 2 of the present invention.

[0035] Figure 6 This is a comparison of the selectivity of carbon dots prepared in Example 1, Comparative Examples 1 and 2 for metal ions in Experiment 3 of the present invention.

[0036] Figure 7 In Experiment 4 of this invention, Fe 3+ Linear relationship between solution concentration and fluorescence intensity of carbon dots in Example 1.

[0037] Figure 8 In Experiment 5 of this invention, the fluorescence intensity results of carbon dots in NaCl solutions of different concentrations were examined.

[0038] Figure 9 In Experiment 6 of this invention, the fluorescence intensity results of carbon dots under different pH conditions were examined.

[0039] Figure 10 This is a graph showing the cytotoxicity detection results of carbon dots in Experiment 7 of this invention.

[0040] Figure 11 This is a diagram showing the results of carbon dots sensing iron ions in cells during Experiment 8 of this invention.

[0041] Figure 12 This is a diagram showing the application results of carbon dots in fluorescent anti-counterfeiting in Embodiment 4 of the present invention.

[0042] Figure 13 This is a diagram showing the application results of carbon dots degrading indigo carmine under sunlight in Embodiment 5 of the present invention. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] The materials and instruments used in the following examples are all commercially available.

[0045] Example 1

[0046] A carbon dot of the present invention, according to Figure 1 The preparation process is as follows:

[0047] (1) Take 45g of Xuefu Zhuyu Decoction residue (the ingredients of Xuefu Zhuyu Decoction are 12g peach kernel, 9g safflower, 9g angelica, 9g rehmannia, 9g achyranthes, 4.5g chuanxiong, 4.5g platycodon, 6g red peony, 6g bitter orange, 6g licorice, and 3g bupleurum) and 100ml anhydrous ethanol and extract at 75℃ for 2-3h to obtain the extract.

[0048] (2) After the extract has cooled naturally, filter to remove solid residue. Transfer the filtrate to a high-pressure reactor lined with polytetrafluoroethylene, add 0.45 g of boric acid, and react at 200 °C for 8 h. After the high-pressure reactor has cooled naturally to room temperature, remove excess ethanol by vacuum distillation. Add water, sonicate to resuspend, and filter to collect the filtrate.

[0049] (3) The filtrate was placed in a 1000 Da biodialysis bag and dialyzed for 72 hours, with the water being changed continuously. The solution in the dialysis bag was collected and freeze-dried for 30 hours. The freeze-dried powder is carbon point, which is stored at 4°C for later use.

[0050] Experiment 1: Characterization of carbon dots in this invention.

[0051] 1. Characterize the morphology of carbon dots using transmission electron microscopy. Figure 2 The figures show the transmission electron microscopy (TEM) and fluorescence properties of the carbon dots; a) is the TEM image; b) is the particle size distribution; c) is the fluorescence image of the carbon dots under different excitation lights; and d) is the fluorescence excitation and emission spectrum of the carbon dots. Fifty particles were analyzed in this experiment, and the average particle size was calculated to be 2.8 ± 0.5 nm.

[0052] 2. The active groups and chemical composition of the carbon dot surface were further characterized using Fourier transform infrared spectroscopy (FT-IR). Figure 3 Infrared spectral characterization of carbon dots; from Figure 3 It can be seen from this that the infrared spectrum is at 3313 cm⁻¹ -1 The presence of an absorption peak at 2926 and 2853 cm⁻¹ indicates the presence of -OH and -NH functional groups on the carbon dot surface. -1 The presence of two absorption peaks at 1706 cm⁻¹ indicates the presence of a C-C bond. -1 The absorption peaks at 1633 and 1040 cm⁻¹ indicate the asymmetric stretching vibration of the C=O bond. -1 These represent the asymmetric stretching vibrations of the O=C-NH and CO bonds, respectively.

[0053] 3. The composition of carbon dots was studied using X-ray photoelectron spectroscopy (XPS). Figure 4 The figure shows the photoelectron spectroscopy characterization of carbon dots; a) is the full XPS spectrum of the carbon dots; b) is the high-resolution C1s spectrum; c) is the high-resolution N1s spectrum; and d) is the high-resolution B1s spectrum. Figure 3 Analysis of the XPS spectrum reveals four peaks at 532.72 eV, 400.09 eV, 284.80 eV, and 192.04 eV, corresponding to the four elements O, N, C, and B, respectively. The C1s spectrum can be decomposed into three peaks at 284.67, 285.96, and 288.78 eV, corresponding to the functional groups CC, CN, and O=CO / COOH. The N1s spectrum is decomposed into peaks at 400.04 and 401.69 eV, corresponding to pyrrole N and pyridine N, respectively. The B1s spectrum is decomposed into peaks at 190.84 and 192.17 eV, corresponding to the functional groups BN and B-CO2.

[0054] Comparative Example 1

[0055] Carbon dots were prepared using the residue of Buyang Huanwu Decoction (formula of Astragalus membranaceus, Paeonia lactiflora, Ligusticum chuanxiong, Angelica sinensis, Pheretima aspergillum, Prunus persica, and Carthamus tinctorius) as raw materials, and the preparation method was the same as in Example 1.

[0056] Comparative Example 2

[0057] Carbon dots were prepared using the residue of Bizhongxiao Decoction (the formula of which includes Hedyotis diffusa, Actinidia chinensis root, Scrophularia ningpoensis, Coix lacryma-jobi, Trachelospermum jasminoides, Achyranthes bidentata, Ligusticum chuanxiong, Salvia miltiorrhiza, Corydalis yanhusuo, Antongteng, Paeonia lactiflora, Astragalus membranaceus, Angelica sinensis, Achyranthes bidentata, Drynaria fortunei, and Glycyrrhiza uralensis) as raw materials, and the preparation method was the same as in Example 1.

[0058] Experiment 2: Investigating the metal ion selectivity of the carbon points in Example 1.

[0059] Specificity is crucial for fluorescent probes. Therefore, this experiment selected 12 metal ions to evaluate their quenching effect on carbon dot fluorescence at the same concentration. The specific experimental procedure was as follows: Ag was tested at a concentration of 200 μM. + Al 3+ Cu 2+ Fe 2+ K + Mg 2+ Mn 2+ Ni 2+ Pb 2+ Zn 2+ Cd 2+ and Fe 3+ The degree of quenching of carbon dot fluorescence. See results below. Figure 5 .

[0060] from Figure 5 It can be seen from this that Fe 3+ The fluorescence quenching effect on carbon dots is the highest, reducing the fluorescence intensity by three times.

[0061] Experiment 3: Investigate the selectivity of carbon dots from three different sources of traditional Chinese medicine compositions for metal ions.

[0062] Twelve metals (Ag) were selected. + Al 3+ Cu 2+ Fe 2+ K + Mg 2+ Mn 2+ Ni 2+ Pb 2+ Zn 2+ Cd 2+ and Fe 3+ The quenching effect on carbon dot fluorescence at the same concentration (200 μM) was evaluated. See the results below. Figure 6 .from Figure 6 The results show that only the carbon dots in Example 1 are selective for metal ions.

[0063] Example 2

[0064] An example of the application of carbon dots in the detection of ferric ions in water is described below. The method involves taking 2 ml of lake water, adding a certain amount of Xuefu Zhuyu Decoction carbon dot solution, controlling the carbon dot concentration at 20 μM, allowing it to stand for 30 minutes, and then measuring the fluorescence intensity using a fluorescence spectrophotometer. Ultrapure water is used as a control. The concentration of ferric ions in the lake water can be calculated based on the standard curve and the change in fluorescence intensity.

[0065] Experiment 4: Investigating the Relationship Between Carbon Points and Fe 3+ Linear relationship of concentration.

[0066] Preparation of Fe gradient concentrations (0–320 μM) 3+ The solution was prepared by adding carbon dot solution and controlling the concentration of carbon dots to 20 μM. After standing for 30 min, the fluorescence intensity was measured using a fluorescence spectrophotometer.

[0067] See results Figure 7 As can be seen from the figure, Fe 3+ The solution concentration and the fluorescence intensity of the carbon dots are linearly related, and the linear regression equation is: y = 0.914 + 0.0111x, R = 0.999.

[0068] Experiment 5: Investigating the effect of NaCl ion concentration on the fluorescence intensity of carbon dots.

[0069] Weigh 0.00100 g of carbon dots using an analytical balance and add 50 ml of deionized water to prepare a stock solution with a concentration of 20 μg / ml. Then, mix 1 ml of the 20 μg / ml carbon dots with different volumes of 2M NaCl solution to prepare mixed solutions with NaCl concentrations of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 M.

[0070] The carbon dot was scanned in the range of 380–700 nm using a fluorescence spectrometer under excitation light at an excitation wavelength of 360 nm to examine the changes in fluorescence intensity of the carbon dot in NaCl solutions of different concentrations. The results are shown below. Figure 8 As can be seen from the figure, the fluorescence intensity of carbon dots changes very little in NaCl solutions of different concentrations, which makes carbon dots more suitable for practical applications.

[0071] Experiment 6: Investigating the effect of pH on the fluorescence intensity of carbon dots

[0072] Similarly, a carbon dot stock solution of 20 μg / ml was prepared using deionized water, and the pH of the carbon dot stock solution was adjusted to 3–11. The fluorescence spectra of carbon dot stock solutions with different pH values ​​were scanned from 380 to 700 nm under excitation light at 360 nm. Figure 9 The graph shows the fluorescence intensity results of the carbon dots under different pH conditions. It can be seen from the graph that the fluorescence intensity changes little within the pH range of 3–9. At pH > 10, the fluorescence intensity increases slightly, indicating that the carbon dots of this invention can operate over a wide pH range.

[0073] Example 3

[0074] An application of carbon dots in the detection of intracellular ferric ions is described in Example 1. The application method is as follows: 10,000 BV2 cells are seeded into 96-well plates, and carbon dot solutions of different concentrations (0, 50, 100, 200 μg / ml) are prepared, added to the 96-well plates, and incubated for 24 h.

[0075] Experiment 7: The cytotoxicity of carbon dots was tested using BV2 microglia.

[0076] Add CCK8 reagent to test cell viability after incubation. Figure 10 The results show the cytotoxicity assay results for carbon dots. As can be seen from the figure, cell viability did not decrease significantly at a concentration of 200 μg / ml. This indicates that carbon dots have good biocompatibility and can be used in biomedicine.

[0077] Experiment 8: HeLa cells were used for cell imaging.

[0078] HeLa cells were used at a density of 5*10 cells per well. 4Cells were seeded at a density in 24-well plates and incubated for 24 hours. Then, 400 μg / ml of carbon dioxide was added, followed by incubation for another 12 hours. The culture medium was washed off with PBS, and the cells were observed under a fluorescence microscope to determine if they exhibited green fluorescence. 400 μg / ml of Fe was added... 3+ After incubation for 6 hours, observe under a fluorescence microscope to see if the fluorescence is quenched.

[0079] Figure 11 This shows the results of carbon dots sensing iron ions within the cell. Figures b and c show the results without added Fe. 3+ Images of cells under bright field and ultraviolet excitation; d and e are images with added Fe, respectively. 3+ Images were taken under bright field and UV excitation. The images show that after HeLa cells were incubated with 400 μg / ml carbon dots for 12 h, the culture medium was washed away with PBS, and the cells showed green fluorescence under a fluorescence microscope; after adding 400 μg / ml Fe... 3+ After incubation for 6 hours, the fluorescence was quenched when observed under a fluorescence microscope, indicating that the carbon dots of the present invention can be used for the detection of intracellular ferric iron, providing a potential application for the detection of iron overload diseases.

[0080] Example 4

[0081] An application of carbon dots in fluorescent anti-counterfeiting and information encryption in Example 1 is described. The application method is as follows: 7.5 ml of PVA aqueous solution (200 mg / ml), 1 ml of anhydrous ethanol and 1.5 ml of carbon dots (3 mg / ml) are mixed, the mixture is written on security paper and photographed under 254 nm ultraviolet light.

[0082] Figure 12 The figure shows the application results of the carbon dots of the present invention in fluorescent anti-counterfeiting. As can be seen from the figure, under 254nm ultraviolet light, the characters written with the mixed liquid can emit bright fluorescence, indicating that the carbon dots of the present invention can be used as fluorescent ink in the field of anti-counterfeiting.

[0083] Example 5

[0084] The application of carbon dots from Example 1 in the photocatalytic degradation of organic dyes and small organic molecules (pesticides, antibiotics, etc.) is as follows:

[0085] I. Indigo carmine solution and Rhodamine B solution with a concentration of 5 μg / ml were prepared separately. 100 μg / ml carbon dot solution was added to the experimental group, and water was added to the control group. The samples were irradiated under sunlight for 4 hours, and the degradation rate of indigo carmine was tracked using an ultraviolet spectrophotometer.

[0086] 2. A solution of indigo carmine with a concentration of 5 μg / ml and carbon dot solutions of different concentrations (100 and 190 μg / ml) were prepared and exposed to sunlight for 5 hours. The degradation rate of indigo carmine was tracked using an ultraviolet spectrophotometer.

[0087] 3. A solution of indigo carmine with a concentration of 5 μg / ml and a solution of carbon dots with a concentration of 190 μg / ml were prepared and irradiated under sunlight for 0, 1, 2, 3, 4 and 5 hours. The degradation rate of indigo carmine was tracked using an ultraviolet spectrophotometer.

[0088] IV. After recycling the carbon dots 1, 2, 3, 4, and 5 times respectively, the degradation rate of indigo carmine by the carbon dots was examined.

[0089] Figure 13 Figures show the application results of carbon dots degrading indigo carmine under sunlight. Figures a and b show the UV absorption of Rhodamine B and indigo carmine after 4 hours of illumination in the absence and presence of carbon dots, respectively; Figure c shows the UV absorption of indigo carmine in solutions with different concentrations of carbon dots after illumination; Figures d and e show the UV absorption of indigo carmine under different illumination times; Figure f shows the degradation rate of indigo carmine after repeated use of carbon dots. The solutions in the glass bottles are electron micrographs of indigo carmine before and after illumination.

[0090] As can be seen from the figure, the degradation rate reached 91% after 5 hours under sunlight. The carbon dots were recycled, and after 5 cycles, the degradation rate of indigo carmine by the carbon dots was higher than 61%, indicating that the carbon dots have good stability and are effective as photocatalysts for degrading small organic molecule dyes.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. The application of carbon dots derived from a traditional Chinese medicine composition in the detection of ferric ions in water, characterized in that, The carbon dots are obtained by extracting the residue of Xuefu Zhuyu Decoction, reacting it with boric acid in a high-pressure reactor, dialysis, and freeze-drying. The residue of Xuefu Zhuyu Decoction is obtained by decocting peach kernel, safflower, angelica, rehmannia root, achyranthes root, chuanxiong rhizome, platycodon root, red peony root, immature bitter orange peel, licorice root, and bupleurum root twice with water and then drying it.

2. The application of carbon dots derived from a traditional Chinese medicine composition in the detection of intracellular ferric ion overload, characterized in that, The carbon dots are obtained by extracting the residue of Xuefu Zhuyu Decoction, reacting it with boric acid in a high-pressure reactor, dialysis, and freeze-drying. The residue of Xuefu Zhuyu Decoction is obtained by decocting peach kernel, safflower, angelica, rehmannia root, achyranthes root, chuanxiong rhizome, platycodon root, red peony root, immature bitter orange peel, licorice root, and bupleurum root twice with water and then drying it.

3. The application of carbon dots derived from a traditional Chinese medicine composition in fluorescent anti-counterfeiting and information encryption, characterized in that, The carbon dots are obtained by extracting the residue of Xuefu Zhuyu Decoction, reacting it with boric acid in a high-pressure reactor, dialysis, and freeze-drying. The residue of Xuefu Zhuyu Decoction is obtained by decocting peach kernel, safflower, angelica, rehmannia root, achyranthes root, chuanxiong rhizome, platycodon root, red peony root, immature bitter orange peel, licorice root, and bupleurum root twice with water and then drying it.

4. The application of carbon dots derived from a traditional Chinese medicine composition in the photocatalytic degradation of organic dyes, pesticides, and antibiotics, characterized in that... The carbon dots are obtained by extracting the residue of Xuefu Zhuyu Decoction, reacting it with boric acid in a high-pressure reactor, dialysis, and freeze-drying. The residue of Xuefu Zhuyu Decoction is obtained by decocting peach kernel, safflower, angelica, rehmannia root, achyranthes root, chuanxiong rhizome, platycodon root, red peony root, immature bitter orange peel, licorice root, and bupleurum root twice with water and then drying it.

5. The application according to any one of claims 1 to 4, characterized in that, The preparation method of the carbon dots derived from the traditional Chinese medicine composition includes the following steps: S1. Extract the Xuefu Zhuyu Decoction residue with ethanol at high temperature to obtain an extract; S2. The extract is transferred to a high-pressure reactor lined with polytetrafluoroethylene, boric acid is added, and the reaction is carried out at 200°C to obtain a reaction solution. S3. The reaction solution was placed into a 1000 Da biodialysis bag for dialysis. The solution in the dialysis bag was collected and freeze-dried to obtain carbon dots.

6. The application according to claim 5, characterized in that, The high-temperature extraction mentioned in S1 specifically refers to extraction at 75°C for 2–3 hours; the ethanol is anhydrous ethanol.

7. The application according to claim 5, characterized in that, Specifically, S2 is: S2-1. After filtering the extract, transfer it to a high-pressure reactor lined with polytetrafluoroethylene, add boric acid, and react at 200℃ for 8 h. S2-2. After the high-pressure reactor cools down naturally, remove excess ethanol by vacuum distillation; add water and sonicate to resuspend, then filter and collect the filtrate.

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