Artemisia argyi-based nitrogen-sulfur co-doped carbon quantum dot as well as preparation method and application thereof

Abstract

The invention provides a wormwood-based nitrogen-sulfur co-doped carbon quantum dot and a preparation method and application thereof.The wormwood-based nitrogen-sulfur co-doped carbon quantum dot is prepared through enzyme pretreatment and microwave-assisted hydrothermal reaction with a wormwood processing by-product as the unique raw material, the particle size is 2-10 nm, the nitrogen content is 3-8 at%, the sulfur content is 1-3 at%, the photothermal conversion efficiency is larger than or equal to 30%, and the fluorescence quantum yield is larger than or equal to 15%; the material has a characteristic absorption peak in a near-infrared band of 700-900 nm, and the absorption peak is in a range of 780-850 nm. According to the method, enzyme pretreatment and a microwave-assisted hydrothermal technology are creatively combined, a remarkable synergistic effect is generated, and the reaction time is shortened to 30 minutes from several hours of conventional hydrothermal treatment. Compared with exogenous doping, wormwood self-doping forms a more uniform doping structure, and the photo-thermal efficiency is improved by 37%. The carbon quantum dots are applied to the field of moxibustion synergism for the first time, the PM2.5 emission of the composite moxibustion stick is reduced by 55%, and the thermal penetration speed is increased by 32%. According to the method, high-value utilization of the wormwood waste is achieved, the preparation process is green and environmentally friendly, the product safety is high, and the method has a definite industrialization prospect.

Description

Technical Field

[0001] This application relates to the technical field of traditional Chinese medicine materials, specifically to a mugwort-based nitrogen-sulfur co-doped carbon quantum dot and its preparation method and application. Background Technology

[0002] Moxibustion is an important component of traditional Chinese medicine, with a clinical application history spanning thousands of years. Moxibustion works by applying the heat radiation generated by burning moxa wool to acupoints on the body, achieving therapeutic effects such as warming the meridians and dispelling cold, supporting Yang and consolidating the body, and resolving stagnation and nodules. Modern research indicates that the therapeutic effects of moxibustion mainly derive from three aspects: thermal effect, photodynamic effect, and the chemical effect of the combustion products of moxa. These three elements work together to provide excellent entropy reduction, energizing, and temperature-regulating effects.

[0003] However, traditional moxibustion techniques have the following problems that urgently need to be addressed:

[0004] (1) Smoke problem: The burning of moxa sticks produces a lot of smoke, of which the PM2.5 concentration can reach hundreds of micrograms per cubic meter. This not only affects the treatment environment, but may also irritate the respiratory system, limiting the application of moxibustion in enclosed spaces and public places.

[0005] (2) Insufficient photothermal penetration: The photothermal heat of traditional moxibustion is mainly transferred through convection and radiation, with limited heat penetration depth, making it difficult to effectively act on deep tissues. Studies have shown that the heat of moxibustion is mainly concentrated in the skin surface, and the temperature rise effect at 5 mm below the skin is significantly reduced. Furthermore, due to the unacceptable photothermal burning pain and scarring, direct moxibustion has gradually withdrawn from clinical practice, and the efficacy of indirect moxibustion has decreased by at least 60%, which urgently needs to be improved.

[0006] (3) Difficulty in temperature control: The burning temperature of moxa sticks is difficult to control precisely, which can easily cause local overheating or insufficient temperature, affecting the therapeutic effect and safety.

[0007] (4) Low spectral utilization: The light radiation generated by burning moxa sticks is mainly concentrated in the visible light and mid-infrared regions, while the near-infrared light (700-900nm), which has the strongest penetrating ability to human tissue, accounts for a relatively low proportion, resulting in low light energy utilization efficiency.

[0008] (5) Standardization problem: The efficacy of traditional moxibustion is affected by a variety of factors such as the quality of the moxa stick, the burning state, and the operation method, making it difficult to achieve standardization and repeatability.

[0009] Carbon quantum dots (CQDs) are a class of zero-dimensional carbon nanomaterials with a particle size of less than 10 nm, possessing excellent optical properties, good biocompatibility, and low toxicity. In recent years, carbon quantum dots have shown broad application prospects in fields such as bioimaging, photothermal therapy, and photodynamic therapy.

[0010] Studies have shown that elemental doping (such as nitrogen, sulfur, and phosphorus) can effectively modulate the band structure and surface states of carbon quantum dots, thereby improving their optical properties. In particular, nitrogen-sulfur co-doped carbon quantum dots can significantly enhance light absorption and photothermal conversion efficiency in the near-infrared region due to the synergistic effect of N and S atoms.

[0011] Currently, the main raw materials for preparing carbon quantum dots include:

[0012] (1) Chemical reagents: such as citric acid, ethylenediamine, thiourea, etc. This type of method has high raw material costs, and some reagents are toxic.

[0013] (2) Natural biomass: such as cellulose, lignin, starch, etc. This type of method has a wide range of raw material sources, but usually requires the addition of nitrogen- or sulfur-containing reagents to achieve doping.

[0014] In the prior art, reports on the preparation of carbon quantum dots from Artemisia argyi mainly focus on fluorescence performance studies. For example, CN113620274A discloses a method for preparing lignin-based nitrogen-sulfur co-doped carbon quantum dots, but requires the addition of urea and thiourea as doping sources; CN119039983A discloses a method for preparing cellulose-based carbon quantum dots, but does not involve elemental doping and photothermal properties.

[0015] Artemisia argyi is a perennial herbaceous plant belonging to the genus Artemisia in the family Asteraceae, and it is widely cultivated in my country. The processing of Artemisia argyi generates a large number of byproducts, including stalks, residue (after extraction), and sieve material. These byproducts are currently mainly treated as waste or used for low-value purposes (such as fuel), resulting in serious resource waste and environmental pressure. Artemisia argyi byproducts naturally contain abundant protein (nitrogen source) and sulfur-containing compounds (sulfur source), showing potential as raw materials for the preparation of carbon quantum dots.

[0016] Therefore, developing a method for preparing carbon quantum dots using mugwort processing by-products as raw materials and utilizing their endogenous nitrogen and sulfur elements for self-doping, and applying it to the field of moxibustion enhancement, has important theoretical significance and application value. Summary of the Invention

[0017] The purpose of this application is to overcome the shortcomings and deficiencies of the prior art and provide an artemisia-based nitrogen-sulfur co-doped carbon quantum dot, its preparation method and application.

[0018] The first aspect of this application provides a mugwort-based nitrogen-sulfur co-doped carbon quantum dot, wherein the carbon quantum dot is prepared by enzyme pretreatment and microwave-assisted hydrothermal reaction using mugwort processing by-products as the sole carbon, nitrogen and sulfur sources.

[0019] The carbon quantum dots have a particle size of 2-10 nm; X-ray photoelectron spectroscopy analysis shows a nitrogen content of 3-8 at% and a sulfur content of 1-3 at%; at a wavelength of 808 nm and a power density of... Under these conditions, the photothermal conversion efficiency is not less than 30%.

[0020] In one embodiment, the carbon quantum dots have a characteristic absorption peak in the 700-900nm near-infrared band, with the absorption peak located in the 780-850nm range.

[0021] In one embodiment, the fluorescence quantum yield of the carbon quantum dots is not less than 15%.

[0022] In one embodiment, the carbon quantum dots can generate singlet oxygen under simulated moxibustion heat radiation conditions, with a singlet oxygen yield of not less than 8 μmol / g.

[0023] In one embodiment, the mugwort processing by-products are selected from one or more combinations of mugwort stalks, mugwort residue, mugwort leaf screenings, and mugwort floss extraction residue.

[0024] As one implementation method, the infrared spectrum of the carbon quantum dots is... It has an absorption peak of amide I at that location, The presence of a CS stretching vibration peak indicates that the characteristic bioactivity information of Artemisia argyi has been preserved.

[0025] A second aspect of this application provides a method for preparing carbon quantum dots as described above, comprising the following steps:

[0026] S1. Raw material pretreatment: Dry the by-products of Artemisia argyi processing to a moisture content of less than 10%, crush and sieve to obtain raw material powder with a particle size of less than 1 mm;

[0027] S2. Enzyme pretreatment: The raw material powder is mixed with water at a mass ratio of 1:5 to 1:20, and an enzyme is added to carry out an enzymatic hydrolysis reaction. The enzymatic hydrolysis temperature is 40-60℃, and the enzymatic hydrolysis time is 2-8 hours to obtain an enzymatic hydrolysate. The enzyme is selected from at least one of cellulase, ligninase, and hemicellulase, and the amount of enzyme added is 0.5%-5% of the dry weight of the raw material powder.

[0028] S3. Microwave-assisted hydrothermal reaction: The enzymatically hydrolyzed slurry is transferred to a closed pressure-resistant reactor and subjected to a hydrothermal reaction under microwave radiation; the microwave power is 300-800W, the reaction temperature is 150-200℃, the reaction time is 10-60 minutes, and the reaction pressure is 0.5-2.0MPa.

[0029] S4. Purification: The hydrothermal reaction product is cooled to room temperature, and large particle precipitates are removed by centrifugation. The supernatant is purified by dialysis. The molecular weight cutoff of the dialysis bag is 1000-3500 Da, and the dialysis time is 24-72 hours. After dialysis, the solution is freeze-dried or spray-dried to obtain the carbon quantum dots.

[0030] In one embodiment, in step S2, the enzyme is cellulase with an enzyme activity of not less than 10,000 U / g, the amount of enzyme added is 1%-3% of the dry weight of the raw material powder, the enzymatic hydrolysis temperature is 45-55℃, and the enzymatic hydrolysis time is 4-6 hours.

[0031] In one implementation method, in step S3, the microwave power is 400-600W, the reaction temperature is 160-180℃, and the reaction time is 20-40 minutes.

[0032] As one implementation, a mechanical pretreatment step is included before step S2: the mixture of raw material powder and water is subjected to high-speed shearing or colloid milling, with a shearing speed of 5000-15000 rpm and a processing time of 5-15 minutes.

[0033] As one implementation method, step S4 is followed by a surface modification step: the purified carbon quantum dots are dispersed in water, and ascorbic acid is added for reduction treatment. The mass ratio of ascorbic acid to carbon quantum dots is in the range of 0.5:1 to 2:1, the reaction temperature is 60-80℃, and the reaction time is 1-3 hours.

[0034] A third aspect of this application provides the application of carbon quantum dots as described above in the preparation of moxibustion enhancement products.

[0035] The moxibustion enhancement product is a composite moxibustion stick, which includes a moxa wool matrix and carbon quantum dots loaded on the moxa wool matrix. The loading amount of the carbon quantum dots is 1-5 wt% of the dry weight of the moxa wool.

[0036] In one embodiment, the moxibustion enhancement product is a moxibustion gel, which contains the carbon quantum dots, a gel matrix, and optionally Artemisia argyi extract, wherein the concentration of the carbon quantum dots in the gel is 0.1-0.5 wt%.

[0037] In one embodiment, the moxibustion enhancement product is a moxibustion patch, which includes a base layer, a functional layer containing the carbon quantum dots, and an adhesive layer.

[0038] A fourth aspect of this application provides a composite moxibustion stick, comprising:

[0039] Artemisia floss matrix;

[0040] Carbon quantum dots as described above, loaded onto the Artemisia argyi matrix;

[0041] The loading of carbon quantum dots is 1-5 wt% of the dry weight of Artemisia argyi.

[0042] When the composite moxibustion stick is burned, PM2.5 emissions are reduced by more than 40% compared to ordinary moxibustion sticks that do not contain carbon quantum dots, and the time to reach 41°C at a subcutaneous depth of 5mm is shortened by more than 25% when applied to a simulated tissue phantom.

[0043] In one embodiment, the carbon quantum dots are loaded onto the surface of mugwort floss by spraying, with a spray concentration of 3-10 mg / mL and a drying temperature of 40-60℃ after spraying.

[0044] A fifth aspect of this application provides a moxibustion gel comprising: carbon quantum dots as described above, with a concentration of 0.1-0.5 wt%;

[0045] The gel matrix is ​​selected from one or more of carbomer, hydroxypropyl methylcellulose, and hyaluronic acid, with iodine cellulose being the preferred choice.

[0046] Artemisia argyi extract;

[0047] When the moxibustion gel is irradiated with 808nm near-infrared light, the surface temperature rises to 40-45℃ within 5 minutes.

[0048] Compared with related technologies, this application has the following advantages:

[0049] (1) Raw material innovation, green and environmentally friendly

[0050] This invention is the first to systematically prepare nitrogen-sulfur co-doped carbon quantum dots using Artemisia argyi processing byproducts as the sole raw material. The naturally occurring proteins (nitrogen source) and sulfur-containing compounds (sulfur source) in Artemisia argyi byproducts participate in the formation and doping of carbon quantum dots in situ during the hydrothermal process, achieving "intrinsic doping." Compared with traditional exogenous doping methods, this invention completely avoids the use of toxic reagents such as urea and thiourea, making the entire preparation process green and environmentally friendly, and the resulting product highly safe.

[0051] (2) Technological innovation and synergistic efficiency

[0052] This invention creatively combines "enzyme pretreatment" with "microwave-assisted hydrothermal" technology:

[0053] The role of enzyme pretreatment: Cellulase and ligninase can efficiently degrade the dense structure of Artemisia argyi cell walls, releasing more soluble small molecule carbon, nitrogen, and sulfur precursors, providing sufficient reactants for the subsequent formation of carbon quantum dots.

[0054] The role of microwave assistance: Microwave heating has the characteristics of internal heating, rapid temperature rise and uniform energy transfer, which can significantly shorten reaction time, improve reaction efficiency and product uniformity.

[0055] Synergistic effect: The combination of the two technologies produces a synergistic effect of "1+1>2". Experimental data show that compared with using enzyme pretreatment or microwave hydrothermal alone, the synergistic effect can increase the yield of carbon quantum dots by more than 50%, the photothermal conversion efficiency by more than 30%, and shorten the reaction time from several hours in conventional hydrothermal treatment to tens of minutes.

[0056] (3) Excellent performance and multiple functions

[0057] The carbon quantum dots obtained in this invention have the following excellent properties:

[0058] Strong near-infrared absorption: It has obvious characteristic absorption peaks in the 700-900nm wavelength range and can effectively absorb near-infrared light;

[0059] High photothermal efficiency: Photothermal conversion efficiency ≥30%, significantly higher than undoped biomass carbon quantum dots (typically <20%).

[0060] Photodynamic activity: It can generate singlet oxygen under thermal excitation conditions and has dual photothermal / photodynamic functions;

[0061] Good biocompatibility: low cytotoxicity, low hemolysis rate, and minimal skin irritation.

[0062] (4) Application innovation leads to significant efficiency gains

[0063] This invention is the first to apply carbon quantum dots to the field of enhancing the efficacy of moxibustion, achieving the following technical effects:

[0064] Smoke reduction effect: When the composite moxibustion stick is burned, PM2.5 emissions are reduced by 40-55%, significantly improving the treatment environment;

[0065] Enhanced effects: Heat penetration rate is increased by 25-35%, and the temperature rise effect in deep subcutaneous tissues is significantly enhanced;

[0066] Spectral optimization: Convert the visible light portion of the fire into near-infrared light to improve light energy utilization efficiency;

[0067] Synergistic effect: Carbon quantum dots and moxibustion heat radiation produce a synergistic effect, achieving a three-in-one effect of "light-heat-chemistry".

[0068] (5) Clear prospects for industrialization

[0069] The preparation process of this invention is clear, using only conventional chemical equipment and raw materials such as Artemisia argyi processing waste, resulting in extremely low costs. The obtained carbon quantum dots can be easily integrated with existing moxibustion product production lines, providing a clear path for industrialization.

[0070] To provide a clearer understanding of this application, the specific embodiments of this application will be described below in conjunction with the accompanying drawings. Attached Figure Description

[0071] Figure 1 This is a schematic diagram of a method for preparing carbon quantum dots according to an embodiment of this application.

[0072] Figure 2 This is a schematic diagram illustrating the performance of a carbon quantum dot according to an embodiment of this application.

[0073] Figure 3 This is a schematic diagram of the experimental results of process parameter optimization according to one embodiment of this application.

[0074] Figure 4 This is a schematic diagram of the chemical composition of a mugwort by-product according to an embodiment of this application.

[0075] Figure 5 This is a schematic diagram showing the product characterization results of Embodiment 2 and Embodiment 1, which are embodiments of this application.

[0076] Figure 6 This is a schematic diagram showing the product characterization results of Embodiment 3 and Embodiment 1, which are embodiments of this application.

[0077] Figure 7 This is a schematic diagram showing the comparison between Embodiments 4-6 and Embodiment 1 of this application.

[0078] Figure 8 This is a schematic diagram showing the comparison between Embodiments 7-9 and Embodiment 1 of this application.

[0079] Figure 9 This is a schematic diagram of the product characterization results of Embodiment 1 and Embodiment 10 of this application.

[0080] Figure 10 This is a schematic diagram of the product characterization results of Embodiment 1 and Embodiment 11 of this application.

[0081] Figure 11 The diagram shows a performance comparison between Comparative Examples 1-6 of one embodiment of this application and Embodiment 1 of this application.

[0082] Figure 12 This is a comparative schematic diagram of Embodiment 1 and Comparative Example 1, which is an embodiment of this application.

[0083] Figure 13 This is a comparative schematic diagram of Embodiment 1 and Comparative Example 2, which is an embodiment of this application.

[0084] Figure 14This is a comparative schematic diagram of four process combinations according to one embodiment of this application.

[0085] Figure 15 This is a comparative schematic diagram of Embodiment 1 of this application and Comparative Examples 3 and 4.

[0086] Figure 16 This is a comparative schematic diagram of Embodiment 1 and Comparative Example 5, which is an embodiment of this application.

[0087] Figure 17 This is a comparative diagram of Embodiment 1 and Comparative Example 6, which is an embodiment of this application. Detailed Implementation

[0088] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0089] It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0090] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. The singular forms "a," "the," and "the" used in this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. The word "if" as used herein can be interpreted as "when," "when," or "in response to determination."

[0091] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0092] The first aspect of this application provides a mugwort-based nitrogen-sulfur co-doped carbon quantum dot, wherein the carbon quantum dot is prepared by enzyme pretreatment and microwave-assisted hydrothermal reaction using mugwort processing by-products as the sole carbon, nitrogen and sulfur sources.

[0093] The carbon quantum dots have a particle size of 2-10 nm; X-ray photoelectron spectroscopy analysis shows a nitrogen content of 3-8 at% and a sulfur content of 1-3 at%; at a wavelength of 808 nm and a power density of... Under these conditions, the photothermal conversion efficiency is not less than 30%.

[0094] In one feasible embodiment, the carbon quantum dots have a characteristic absorption peak in the 700-900nm near-infrared band, with the absorption peak located in the 780-850nm range.

[0095] In one feasible embodiment, the fluorescence quantum yield of the carbon quantum dots is not less than 15%.

[0096] In one feasible embodiment, the carbon quantum dots are able to generate singlet oxygen under simulated moxibustion heat radiation conditions, with a singlet oxygen yield of not less than 8 μmol / g.

[0097] In one feasible embodiment, the mugwort processing by-products are selected from one or more combinations of mugwort stalks, mugwort residue, mugwort leaf screenings, and mugwort floss extraction residues.

[0098] In one feasible embodiment, the infrared spectrum of the carbon quantum dots is in It has an absorption peak of amide I at that location, The presence of a CS stretching vibration peak indicates that the characteristic bioactivity information of Artemisia argyi has been preserved.

[0099] Please see Figure 1 The second aspect of this application provides a method for preparing carbon quantum dots as described above, comprising the following steps:

[0100] S1. Raw material pretreatment: Dry the by-products of Artemisia argyi processing to a moisture content of less than 10%, crush and sieve to obtain raw material powder with a particle size of less than 1 mm;

[0101] S2. Enzyme pretreatment: The raw material powder is mixed with water at a mass ratio of 1:5 to 1:20, and an enzyme is added to carry out an enzymatic hydrolysis reaction. The enzymatic hydrolysis temperature is 40-60℃, and the enzymatic hydrolysis time is 2-8 hours to obtain an enzymatic hydrolysate. The enzyme is selected from at least one of cellulase, ligninase, and hemicellulase, and the amount of enzyme added is 0.5%-5% of the dry weight of the raw material powder.

[0102] S3. Microwave-assisted hydrothermal reaction: The enzymatically hydrolyzed slurry is transferred to a closed pressure-resistant reactor and subjected to a hydrothermal reaction under microwave radiation; the microwave power is 300-800W, the reaction temperature is 150-200℃, the reaction time is 10-60 minutes, and the reaction pressure is 0.5-2.0MPa.

[0103] S4. Purification: The hydrothermal reaction product is cooled to room temperature, and large particle precipitates are removed by centrifugation. The supernatant is purified by dialysis. The molecular weight cutoff of the dialysis bag is 1000-3500 Da, and the dialysis time is 24-72 hours. After dialysis, the solution is freeze-dried or spray-dried to obtain the carbon quantum dots.

[0104] It is worth noting that mugwort has a unique chemical composition:

[0105] (1) High protein content: The protein content in the dry matter of Artemisia argyi can reach 8-15%, which is significantly higher than that of ordinary crop straw (3-6%), making it a potential high-quality nitrogen source.

[0106] (2) Rich in sulfur compounds: Artemisia argyi contains a variety of sulfur-containing amino acids (such as cysteine ​​and methionine) and sulfur-containing active ingredients, which are natural sulfur sources.

[0107] (3) Moderate cellulose and lignin content: provides sufficient carbon source for the carbon skeleton of carbon quantum dots.

[0108] Based on the above analysis, Artemisia argyi byproducts have unique advantages as raw materials for the preparation of carbon quantum dots: they can provide carbon, nitrogen and sulfur sources at the same time, and are expected to achieve "internal source doping" and avoid the use of external toxic reagents.

[0109] Please see Figure 2 The properties of carbon quantum dots from Artemisia argyi byproducts relative to other raw materials, such as Figure 2 As shown, it is clear that the photothermal efficiency of carbon prepared from mugwort by-products is significantly better than that of other raw materials.

[0110] In a feasible embodiment, in step S2, the enzyme is cellulase with an enzyme activity of not less than 10,000 U / g, the amount of enzyme added is 1%-3% of the dry weight of the raw material powder, the enzymatic hydrolysis temperature is 45-55℃, and the enzymatic hydrolysis time is 4-6 hours.

[0111] In one feasible embodiment, in step S3, the microwave power is 400-600W, the reaction temperature is 160-180℃, and the reaction time is 20-40 minutes.

[0112] In one feasible embodiment, a mechanical pretreatment step is included before step S2: the mixture of raw material powder and water is subjected to high-speed shearing or colloid milling at a shearing speed of 5000-15000 rpm for a processing time of 5-15 minutes.

[0113] In a feasible embodiment, step S4 is followed by a surface modification step: the purified carbon quantum dots are dispersed in water, and ascorbic acid is added for reduction treatment. The mass ratio of ascorbic acid to carbon quantum dots is in the range of 0.5:1 to 2:1, the reaction temperature is 60-80°C, and the reaction time is 1-3 hours.

[0114] Please see Figure 3 The experimental results of process parameter optimization in this application are as follows: Figure 3 As shown.

[0115] A third aspect of this application provides the application of carbon quantum dots as described above in the preparation of moxibustion enhancement products.

[0116] The moxibustion enhancement product is a composite moxibustion stick, which includes a moxa wool matrix and carbon quantum dots loaded on the moxa wool matrix. The loading amount of the carbon quantum dots is 1-5 wt% of the dry weight of the moxa wool.

[0117] In one feasible embodiment, the moxibustion enhancement product is a moxibustion gel, which contains the carbon quantum dots, a gel matrix, and optionally Artemisia argyi extract, wherein the concentration of the carbon quantum dots in the gel is 0.1-0.5 wt%.

[0118] In one feasible embodiment, the moxibustion enhancement product is a moxibustion patch, which includes a base layer, a functional layer containing the carbon quantum dots, and an adhesive layer, wherein the functional layer is located between the base layer and the adhesive layer.

[0119] A fourth aspect of this application provides a composite moxibustion stick, comprising:

[0120] Artemisia floss matrix;

[0121] Carbon quantum dots as described above, loaded onto the Artemisia argyi matrix;

[0122] The loading of carbon quantum dots is 1-5 wt% of the dry weight of Artemisia argyi.

[0123] When the composite moxibustion stick is burned, PM2.5 emissions are reduced by more than 40% compared to ordinary moxibustion sticks that do not contain carbon quantum dots, and the time to reach 41°C at a subcutaneous depth of 5mm is shortened by more than 25% when applied to a simulated tissue phantom.

[0124] In one feasible embodiment, the carbon quantum dots are loaded onto the surface of Artemisia argyi by spraying, with a spray concentration of 3-10 mg / mL and a drying temperature of 40-60°C after spraying.

[0125] A fifth aspect of this application provides a moxibustion gel comprising: carbon quantum dots as described above, with a concentration of 0.1-0.5 wt%;

[0126] The gel matrix is ​​selected from one or more of carbomer, hydroxypropyl methylcellulose, and hyaluronic acid, with iodine cellulose being the preferred choice.

[0127] Artemisia argyi extract;

[0128] When the moxibustion gel is irradiated with 808nm near-infrared light, the surface temperature rises to 40-45℃ within 5 minutes.

[0129] The mugwort by-products used in this application are derived from waste generated during the processing of mugwort floss, and mainly include:

[0130] (1) Artemisia argyi stem: The stem part of Artemisia argyi is discarded as waste after the leaves are harvested;

[0131] (2) Artemisia residue: The residue after Artemisia leaves are crushed, sieved and extracted to extract Artemisia floss, mainly consisting of leaf veins, petioles and other fibrous tissues.

[0132] Preferably, the mugwort by-product is a processing by-product of three-year-aged mugwort. The chemical composition of the mugwort by-product is as follows: Figure 4 As shown, from Figure 4 It can be seen that the protein content of Artemisia argyi by-products is relatively high (11.2%), the total nitrogen content reaches 1.79%, and the total sulfur content reaches 0.42%, providing a sufficient source of elements for nitrogen and sulfur self-doping of carbon quantum dots.

[0133] The processing of mugwort by-products includes: drying the mugwort by-products in a 60℃ oven to constant weight (moisture content <10%), then pulverizing them using a pulverizer and passing them through a 60-mesh sieve (0.25mm aperture), collecting the sieve-passing material as raw material powder. The raw material powder is sealed and stored in a dry, cool place for later use.

[0134] The following description will be based on embodiments of this application:

[0135] Example 1: Preparation of carbon quantum dots under optimal process conditions

[0136] S1, Raw material pretreatment

[0137] Take 500g of mugwort by-product (mugwort residue), dry it in a 60℃ oven for 24 hours until the moisture content is 8%, crush it with a high-speed pulverizer, pass it through a 60-mesh sieve, and collect the sieve residue as raw material powder.

[0138] S2, Enzyme Pretreatment

[0139] Weigh 50g of raw material powder, add 1000mL of deionized water (material-to-liquid ratio 1:20), stir well, and then add 0.1mol / L hydrochloric acid solution to adjust the pH to 5.0. Add 1.0g of cellulase (enzyme activity 15000U / g, addition amount is 2% of the dry weight of raw material), and stir in a 50℃ constant temperature water bath for 5 hours to obtain enzymatic hydrolysate.

[0140] S3, Microwave-assisted hydrothermal reaction

[0141] The enzymatically hydrolyzed slurry was transferred to a 500 mL PTFE-lined microwave hydrothermal reactor, sealed, and placed in a microwave reactor (model: CEMDiscoverSP). The microwave power was set to 500 W, the reaction temperature to 170 °C, and the reaction time to 30 minutes. After the reaction, the mixture was allowed to cool naturally to room temperature.

[0142] S4, Purification

[0143] The reaction solution was centrifuged at 12,000 rpm for 15 minutes, and the supernatant was collected. The supernatant was filtered through a 0.22 μm microporous membrane and then transferred to a dialysis bag with a molecular weight cutoff of 1000 Da. Dialysis was performed in deionized water for 48 hours (with water changed every 8 hours). The dialysis solution was then freeze-dried to obtain a dark brown solid powder, which is the nitrogen-sulfur co-doped carbon quantum dot (designated A-CQDs-1).

[0144] Product characterization results:

[0145] (1) Yield: Based on the dry weight of raw materials, the yield is 12.6%.

[0146] (2) Morphology and particle size: HRTEM images show that the carbon quantum dots are spherical or near-spherical, well dispersed, and without obvious agglomeration. Statistical analysis of particle size distribution shows that the particle size is mainly concentrated in the range of 2-5 nm, with an average particle size of 3.2 nm.

[0147] (3) Elemental composition: XPS analysis showed that carbon quantum dots are mainly composed of four elements: C, N, O, and S. The contents of each element are: C 68.5 at%, N 5.2 at%, O 24.5 at%, and S 1.8 at%. The N1s high-resolution spectrum showed that nitrogen mainly exists in the form of pyridine nitrogen (398.5 eV) and pyrrole nitrogen (400.1 eV); the S2p high-resolution spectrum showed that sulfur mainly exists in the form of thiophene sulfur (163.8 eV) and sulfur oxide (168.2 eV).

[0148] (4) Optical properties: UV-Vis-NIR absorption spectroscopy shows that carbon quantum dots have a strong absorption peak at 280 nm (π-π transition), a shoulder peak at 350 nm (n-π transition), and a broad absorption band in the near-infrared region of 700-900 nm, with the absorption peak located at 815 nm. Fluorescence spectroscopy shows that under 360 nm excitation, the emission peak is located at 450 nm, and the fluorescence quantum yield is 18.5%.

[0149] (5) Photothermal performance: In 808nm laser ( Under irradiation, a 200 μg / mL carbon quantum dot dispersion heated from 25 °C to 52.3 °C within 10 minutes, a temperature rise of 27.3 °C. The calculated photothermal conversion efficiency was 35.2%.

[0150] (6) Singlet oxygen yield: ESR test showed that carbon quantum dots can produce singlet oxygen at a yield of 10.5 μmol / g under heating conditions of 45 °C.

[0151] Example 2: Verification of the lower limit of parameter range

[0152] The difference between Example 2 and Example 1 lies in the use of the lower limit of the parameter range, as detailed below:

[0153] Enzyme addition: 0.5% (dry weight of raw materials);

[0154] Enzymatic hydrolysis time: 2 hours;

[0155] Microwave power: 300W;

[0156] Reaction temperature: 150℃;

[0157] Reaction time: 10 minutes.

[0158] The other steps in Example 2 are the same as in Example 1, wherein the product characterization results of Example 2 and Example 1 are as follows: Figure 5 As shown, the results indicate that carbon quantum dots that meet the requirements can still be prepared under the lower limit of the parameter range (the requirement of photothermal efficiency ≥30% is slightly insufficient, but close), but the yield and performance are slightly lower than the optimal conditions.

[0159] Example 3: Verification of the upper limit of parameter range

[0160] The difference between Example 3 and Example 1 is that the upper limit of the parameter range is used, as detailed below:

[0161] Enzyme addition: 5% (dry weight of raw materials)

[0162] Enzymatic hydrolysis time: 8 hours;

[0163] Microwave power: 800W;

[0164] Reaction temperature: 200℃;

[0165] Reaction time: 60 minutes

[0166] The other steps in Example 3 are the same as in Example 1, wherein the product characterization results of Example 3 and Example 1 are as follows: Figure 6 As shown, the results indicate that, under the upper limit of the parameter range, due to excessive reaction, some carbon quantum dots agglomerate, resulting in increased particle size and a slight decrease in performance, but still meet the technical specifications of the claims.

[0167] Please see Figure 7 To verify the effect of enzyme addition on the performance of carbon quantum dots, experiments were conducted with different enzyme addition amounts under the same conditions as in Example 1, and the results of Examples 4-6 were compared with those of Example 1. The results showed that: (1) When the enzyme addition amount was less than 0.5%, the enzymatic hydrolysis was insufficient, the degree of cell wall breakdown was low, and the release of small molecule precursors was insufficient, resulting in low yield and doping level; (2) When the enzyme addition amount was in the range of 1-3%, the yield and performance were both good, and the optimal addition amount was 2%; (3) When the enzyme addition amount exceeded 3%, the performance improvement was not obvious, but the cost increased and the economic efficiency decreased.

[0168] Please see Figure 8 To verify the effect of microwave power on the performance of carbon quantum dots, experiments were conducted with different microwave powers under the same conditions as in Example 1, and the results of Examples 7-9 were compared with those of Example 1. The results showed that: (1) When the microwave power was too low (<400W), the heating was insufficient, the degree of carbonization was insufficient, and the yield and performance were low; (2) When the microwave power was in the range of 400-600W, the yield and performance were both good, and the optimal power was 500W; (3) When the microwave power was too high (>700W), local overheating caused the carbon quantum dots to agglomerate, the particle size increased, and the performance decreased.

[0169] Please see Figure 9 Based on Example 1, a mechanical pretreatment step was added before enzyme pretreatment to obtain Example 10. The mechanical pretreatment step involved placing a mixture of raw material powder and water in a high-speed shear mill and shearing it at 10,000 rpm for 10 minutes, followed by enzyme pretreatment and subsequent steps. The product characterization results of Examples 1 and 10 are as follows: Figure 9 As shown in the figure. The results indicate that mechanical pretreatment can further disrupt the cell wall structure, release more small molecule precursors, and significantly improve yield and performance.

[0170] Please see Figure 10 Based on Example 1, a surface modification step was added after the purification step to obtain Example 11. The added surface modification step included: dispersing 100 mg of purified carbon quantum dots in 100 mL of deionized water, adding 100 mg of ascorbic acid, and stirring the mixture at 70°C for 2 hours. After the reaction, the mixture was purified by dialysis and freeze-dried to obtain surface-modified carbon quantum dots. The product characterization results of Examples 1 and 11 are as follows: Figure 10 As shown, the results indicate that ascorbic acid reduction treatment can optimize the surface states of carbon quantum dots, making the near-infrared absorption peak closer to the 808 nm laser wavelength and improving photothermal efficiency, but the fluorescence quantum yield decreases slightly.

[0171] To further illustrate the technical solution of this application, the following description will be provided in conjunction with comparative examples:

[0172] Comparative Example 1: Enzyme-free pretreatment (Product No.: D-CQDs-1)

[0173] The difference between this comparative example and Example 1 is that the enzyme pretreatment step is omitted, and the raw material powder is directly mixed with water and subjected to microwave hydrothermal reaction.

[0174] Specific steps: Weigh 50g of raw material powder, add 1000mL of deionized water, stir well, and then directly transfer to a microwave hydrothermal reactor. React at 500W and 170℃ for 30 minutes. Subsequent purification steps are the same as in Example 1.

[0175] Comparative Example 2: Conventional hydrothermal (without microwave assistance, product number: D-CQDs-2)

[0176] The difference between this comparative example and Example 1 is that conventional oil bath heating is used instead of microwave heating.

[0177] Specific steps: The enzyme pretreatment steps are the same as in Example 1. The enzymatically hydrolyzed slurry is transferred to a stainless steel reactor lined with polytetrafluoroethylene and heated in an oil bath at 170°C for 10 hours. Subsequent purification steps are the same as in Example 1.

[0178] Comparative Example 3: Corn Stalk Raw Material (Product No.: D-CQDs-3)

[0179] The difference between this comparative example and Example 1 is that corn stalks are used instead of Artemisia argyi by-products as raw materials.

[0180] The chemical composition of corn stalks is as follows: crude protein 4.2%, total nitrogen 0.67%, total sulfur 0.15%, cellulose 42.5%, and lignin 18.2%. All other steps are identical to those in Example 1.

[0181] Comparative Example 4: Rice straw raw material (Product No.: D-CQDs-4)

[0182] The difference between this comparative example and Example 1 is that rice straw is used instead of Artemisia argyi byproducts as raw material.

[0183] The chemical composition of the rice straw was: crude protein 5.1%, total nitrogen 0.82%, total sulfur 0.18%, cellulose 38.6%, and lignin 15.5%. The other steps were exactly the same as in Example 1.

[0184] Comparative Example 5: Exogenous Doping (Product No.: D-CQDs-5)

[0185] This comparative example uses pure cellulose as raw material, with urea and thiourea added as nitrogen and sulfur sources, respectively.

[0186] Specific steps: Weigh 50g of microcrystalline cellulose, add 1000mL of deionized water, add 5g of urea and 2g of thiourea, stir evenly, and then carry out enzyme pretreatment and microwave hydrothermal reaction. Other steps are the same as in Example 1.

[0187] Comparative Example 6: Undoped carbon quantum dots (Product No.: D-CQDs-6)

[0188] This comparative example uses pure cellulose as raw material, without adding any nitrogen or sulfur sources.

[0189] Specific steps: Weigh 50g of microcrystalline cellulose, add 1000mL of deionized water, and carry out enzyme pretreatment and microwave hydrothermal reaction. Other steps are the same as in Example 1.

[0190] Among them, the performance comparisons of Comparative Examples 1-6 with Embodiment 1 of this application are as follows: Figure 11 As shown, QY = fluorescence quantum yield; η = photothermal conversion efficiency (808nm, 1.0W / cm²).

[0191] The comparative analysis and inventive step demonstration of Comparative Examples 1-6 and Example 1 of this application are as follows:

[0192] 1. Necessity analysis of enzyme pretreatment: Comparison of Example 1 (enzyme + microwave) and Comparative Example 1 (no enzyme + microwave) as follows... Figure 12 As shown, enzyme pretreatment effectively degrades the dense structure of Artemisia argyi cell walls, releasing more soluble small-molecule carbon, nitrogen, and sulfur precursors. These small-molecule precursors are more likely to participate in the nucleation and growth of carbon quantum dots during hydrothermal processes, achieving more efficient elemental doping. Without enzyme pretreatment, the cell wall structure is not sufficiently disrupted, and most nitrogen and sulfur elements remain encapsulated within the cell wall, unable to effectively participate in the doping reaction, leading to a significant decrease in yield and performance.

[0193] 2. Necessity analysis of microwave-assisted treatment: The results of comparative example 1 (enzyme + microwave) and comparative example 2 (enzyme + conventional hydrothermal treatment) are as follows: Figure 13 As shown, the essential difference between microwave heating and conventional heating lies in the energy transfer method. Microwave heating achieves "internal heating" by directly applying an electromagnetic field to polar molecules, resulting in rapid temperature rise, uniform temperature, and high energy utilization. In the preparation of carbon quantum dots, microwave assistance can: (1) quickly reach the reaction temperature and shorten the reaction time; (2) provide uniform heating and avoid uneven carbonization caused by local overheating; (3) promote the rapid carbonization and nucleation of small molecule precursors to form carbon quantum dots with uniform particle size; and (4) reduce oxidation side reactions caused by prolonged heating and retain more dopant elements. Therefore, although conventional hydrothermal heating can also produce carbon quantum dots, the reaction time is as long as 10 hours, and the yield and performance are not as good as the microwave-assisted process.

[0194] 3. Verification of synergistic effect

[0195] Please see Figure 14 To verify whether there is a synergistic effect between enzyme pretreatment and microwave assistance, we compared the results of four process combinations. The theoretical superposition value = (no enzyme + microwave) + (enzyme + conventional hydrothermal) - (no enzyme + conventional hydrothermal). Figure 14 It can be concluded that: (1) the yield of Example 1 (12.6%) is higher than the theoretical superposition value (9.7%), with an increase of 30%; (2) the photothermal efficiency of Example 1 (35.2%) is higher than the theoretical superposition value (33.0%), with an increase of 7%; (3) this indicates that there is a synergistic effect of “1+1>2” between enzyme pretreatment and microwave assistance.

[0196] Table 2 Performance Comparison of Four Process Combinations

[0197]

[0198] Synergistic effect calculation:

[0199] (1) Analysis of yield synergy

[0200] Enzyme pretreatment alone contributes (BA): 18.2% - 12.5% ​​= 5.7%

[0201] Microwave-assisted contribution alone (CA): 15.8% - 12.5% ​​= 3.3%

[0202] Expected additive effect: 5.7% + 3.3% = 9.0%

[0203] Actual synergy (DA): 28.5% - 12.5% ​​= 16.0%

[0204] Synergistic gain: 16.0% - 9.0% = 7.0% (synergistic gain rate 78%)

[0205] (2) Analysis of the synergistic effect of photothermal efficiency

[0206] Enzyme pretreatment alone contributes (BA): 28.5% - 22.3% = 6.2%

[0207] Microwave-assisted contribution alone (CA): 26.8% - 22.3% = 4.5%

[0208] Expected additive effect: 6.2% + 4.5% = 10.7%

[0209] Actual synergistic effect (DA): 35.2% - 22.3% = 12.9%

[0210] Synergistic gain: 12.9% - 10.7% = 2.2% (synergistic gain rate 21%)

[0211] (3) Analysis of the synergistic effect of quantum yield

[0212] Enzyme pretreatment alone contributes (BA): 12.8% - 8.5% = 4.3%

[0213] Microwave-assisted contribution alone (CA): 11.2% - 8.5% = 2.7%

[0214] Expected additive effect: 4.3% + 2.7% = 7.0%

[0215] Actual synergy (DA): 18.5% - 8.5% = 10.0%

[0216] Synergistic gain: 10.0% - 7.0% = 3.0% (synergistic gain rate 43%)

[0217] Table 3 Summary of Synergistic Effects

[0218]

[0219] Conclusion: The combination of enzyme pretreatment and microwave-assisted hydrothermal treatment produced a significant synergistic effect, with actual results significantly better than the simple sum of the effects of using the two techniques alone. This "1+1>2" synergistic effect is one of the core innovations of this invention.

[0220] Synergistic Mechanism Analysis:

[0221] (1) Enzyme pretreatment disrupts the dense structure of Artemisia argyi cell wall, releasing more soluble small molecule precursors;

[0222] (2) These small molecule precursors can absorb microwave energy more uniformly in a microwave field, achieving rapid and uniform carbonization and doping;

[0223] (3) The selective heating characteristics of microwaves allow precursors containing polar groups (such as -NH2, -SH) to react preferentially, which is beneficial to the efficient doping of N and S elements;

[0224] (4) The synergistic effect of the two technologies makes the nucleation and growth process of carbon quantum dots more controllable and the particle size distribution of the product more uniform.

[0225] 4. Specificity analysis of Artemisia argyi raw materials (Example 1 vs. Comparative Examples 3 and 4)

[0226] The results of comparing Example 1 (Artemisia argyi byproducts) with Comparative Example 3 (corn stalks) and Comparative Example 4 (rice straw) are as follows: Figure 15 As shown. According to Figure 15It can be seen that: (1) the nitrogen content of Artemisia argyi by-products (1.79%) is 2.7 times that of corn stalks (0.67%) and 2.2 times that of rice straw (0.82%); (2) the sulfur content of Artemisia argyi by-products (0.42%) is 2.8 times that of corn stalks (0.15%) and 2.3 times that of rice straw (0.18%); (3) due to the difference in N and S content in the raw materials, the doping level and photothermal efficiency of Artemisia argyi-based carbon quantum dots are significantly higher than those of other biomass-based carbon quantum dots. This result indicates that Artemisia argyi by-products have unique advantages as raw materials for the preparation of carbon quantum dots. This advantage stems from the chemical composition characteristics of Artemisia argyi itself, rather than a simple replacement of raw materials.

[0227] 5. Comparison of self-doping and exogenous doping (Example 1 vs. Comparative Example 5)

[0228] The results of comparing Example 1 (Artemisia argyi self-doping) and Comparative Example 5 (cellulose + exogenous doping) are as follows: Figure 16 As shown, according to Figure 15 It can be seen that: (1) Although the N and S content of exogenous doping is slightly higher than that of self-doping, the photothermal efficiency and quantum yield are significantly lower than those of self-doping; (2) This indicates that the doping effect depends not only on the content of the doping element, but also on the chemical state and distribution mode of the doping element; (3) In the self-doping process of Artemisia argyi, the N and S elements come from proteins and sulfur-containing amino acids. These molecules are formed synchronously with the carbon skeleton during the hydrothermal process, and the doping elements can be more evenly distributed on the lattice and surface of carbon quantum dots, forming an electronic structure that is more conducive to photothermal conversion; (4) In exogenous doping, the N and S atoms released by the decomposition of urea and thiourea at high temperature may mainly adsorb on the surface of carbon quantum dots, and the doped structure formed is not as uniform and stable as that of self-doping. In addition, exogenous doping requires the use of chemical reagents such as urea and thiourea, which poses potential biosafety risks, while self-doping makes full use of the endogenous elements of Artemisia argyi, which is more green and environmentally friendly.

[0229] Table 4 Comparison of Chemical Composition of Different Biomass Raw Materials

[0230]

[0231] Table 5. Performance comparison of carbon quantum dots prepared from different biomass feedstocks

[0232]

[0233] in conclusion:

[0234] (1) The nitrogen content of mugwort by-products is 2.7 times that of corn stalks and 2.2 times that of rice straw;

[0235] (2) The sulfur content of mugwort by-products is 2.8 times that of corn stalks and 2.3 times that of rice straw;

[0236] (3) Due to the difference in N and S content in the raw materials, the doping level and photothermal efficiency of Artemisia argyi-based carbon quantum dots are significantly higher than those of other biomass-based carbon quantum dots;

[0237] (4) Artemisia argyi by-products have unique advantages as raw materials for the preparation of carbon quantum dots, which cannot be replaced by other common biomass raw materials.

[0238] 6. Necessity analysis of doping (Example 1 vs. Comparative Example 6)

[0239] The results of comparing Example 1 (N,S co-doped) and Comparative Example 6 (undoped) are as follows: Figure 17 As shown, according to Figure 17 It can be concluded that N and S co-doping significantly improves the photothermal efficiency and quantum yield of carbon quantum dots. This is because: (1) The introduction of N atoms can form pyridine nitrogen and pyrrole nitrogen structures in carbon quantum dots, which can regulate the band structure of carbon quantum dots and enhance light absorption in the near-infrared region; (2) The introduction of S atoms can form thiophene sulfur structures, further regulate the electron cloud distribution, promote the separation of photogenerated electron-hole pairs and non-radiative relaxation processes, and improve photothermal conversion efficiency; (3) The synergistic effect of N and S gives carbon quantum dots a narrower band gap and stronger near-infrared absorption capability.

[0240] To further verify the advantages of endogenous doping over exogenous doping in Artemisia argyi, the following comparative analysis was conducted (see [link to relevant documentation]). Figure 16 ).

[0241] Table 6. Performance Comparison of Self-Doping and Exogenous Doping

[0242]

[0243] Key findings: Although the N and S contents of exogenous doping are slightly higher than those of self-doping, the photothermal efficiency is significantly lower (25.6% vs 35.2%). This "anomaly" indicates that the doping effect depends not only on the content of the dopant element, but also on the chemical state and spatial distribution of the dopant element.

[0244] Cause analysis:

[0245] (1) Difference in doping uniformity: During the self-doping process of Artemisia argyi, N and S elements are derived from proteins and sulfur-containing amino acids. These molecules are formed synchronously with the carbon skeleton during the hydrothermal process, and the doping elements can be more uniformly distributed in the lattice and surface of carbon quantum dots. During exogenous doping, the N and S released by the decomposition of urea and thiourea during the hydrothermal process may mainly remain on the surface of carbon quantum dots, and the doped structure formed is not as uniform as that of self-doping.

[0246] (2) Differences in chemical bonding: Sulfur-containing amino acids in Artemisia argyi (such as cysteine ​​and methionine) may form a special CSC thiophene structure, which is more favorable for photothermal conversion. The sulfur formed by exogenous thiourea doping is mainly in the oxidized state ( ), with low photothermal activity.

[0247] (3) Retention of characteristic active ingredients of Artemisia argyi: During the self-doping process of Artemisia argyi, some characteristic active ingredients of Artemisia argyi (such as flavonoids and terpenoids) may participate in the formation of carbon quantum dots, giving them unique optical properties.

[0248] The device embodiments described above are merely illustrative. The components described as separate parts may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this application according to actual needs. Those skilled in the art can understand and implement this without any inventive effort.

[0249] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0250] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function selected in one or more boxes.

[0251] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function selected in one or more boxes.

[0252] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0253] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0254] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0255] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0256] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A kind of Artemisia argyi-based nitrogen-sulfur co-doped carbon quantum dot, characterized in that: The carbon quantum dots were prepared by enzyme pretreatment and microwave-assisted hydrothermal reaction using Artemisia argyi processing by-products as the sole carbon, nitrogen and sulfur sources. The carbon quantum dots have a particle size of 2-10 nm; X-ray photoelectron spectroscopy analysis shows a nitrogen content of 3-8 at% and a sulfur content of 1-3 at%; at a wavelength of 808 nm and a power density of... Under these conditions, the photothermal conversion efficiency is not less than 30%.

2. The carbon quantum dot according to claim 1, characterized in that, The carbon quantum dots have characteristic absorption peaks in the 700-900nm near-infrared band, with the absorption peaks located in the 780-850nm range.

3. The carbon quantum dot according to claim 1, characterized in that, The fluorescence quantum yield of the carbon quantum dots is not less than 15%.

4. The carbon quantum dot according to claim 1, characterized in that, The carbon quantum dots can generate singlet oxygen under simulated moxibustion heat radiation conditions, with a singlet oxygen yield of not less than 8 μmol / g.

5. The carbon quantum dot according to claim 1, characterized in that, The processed byproducts of Artemisia argyi are selected from one or more combinations of Artemisia argyi stems, Artemisia argyi residue, Artemisia argyi leaf screenings, and Artemisia argyi floss extraction residue.

6. The carbon quantum dot according to claim 1, characterized in that, The infrared spectrum of the carbon quantum dots is It has an absorption peak of amide I at that location, It exhibits a CS stretching vibration peak.

7. A method for preparing carbon quantum dots as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Raw material pretreatment: Dry the by-products of Artemisia argyi processing to a moisture content of less than 10%, crush and sieve to obtain raw material powder with a particle size of less than 1 mm; S2. Enzyme pretreatment: The raw material powder is mixed with water at a mass ratio of 1:5 to 1:20, and an enzyme is added to carry out an enzymatic hydrolysis reaction. The enzymatic hydrolysis temperature is 40-60℃, and the enzymatic hydrolysis time is 2-8 hours to obtain an enzymatic hydrolysate. The enzyme is selected from at least one of cellulase, ligninase, and hemicellulase, and the amount of enzyme added is 0.5%-5% of the dry weight of the raw material powder. S3. Microwave-assisted hydrothermal reaction: The enzymatically hydrolyzed slurry is transferred to a closed pressure-resistant reactor and subjected to a hydrothermal reaction under microwave radiation; the microwave power is 300-800W, the reaction temperature is 150-200℃, the reaction time is 10-60 minutes, and the reaction pressure is 0.5-2.0MPa. S4. Purification: The hydrothermal reaction product is cooled to room temperature, and large particle precipitates are removed by centrifugation. The supernatant is purified by dialysis. The molecular weight cutoff of the dialysis bag is 1000-3500 Da, and the dialysis time is 24-72 hours. After dialysis, the solution is freeze-dried or spray-dried to obtain the carbon quantum dots.

8. The method according to claim 6, characterized in that, In step S2, the enzyme is cellulase with an enzyme activity of not less than 10,000 U / g. The amount of enzyme added is 1%-3% of the dry weight of the raw material powder. The enzymatic hydrolysis temperature is 45-55℃ and the enzymatic hydrolysis time is 4-6 hours.

9. The method according to claim 7, characterized in that, In step S3, the microwave power is 400-600W, the reaction temperature is 160-180℃, and the reaction time is 20-40 minutes.

10. The method according to claim 7, characterized in that, Before step S2, there is also a mechanical pretreatment step: the mixture of raw material powder and water is subjected to high-speed shearing or colloid milling, with a shearing speed of 5000-15000 rpm and a processing time of 5-15 minutes.

11. The method according to claim 7, characterized in that, Step S4 is followed by a surface modification step: the purified carbon quantum dots are dispersed in water, and ascorbic acid is added for reduction treatment. The mass ratio of ascorbic acid to carbon quantum dots is in the range of 0.5:1 to 2:1, the reaction temperature is 60-80℃, and the reaction time is 1-3 hours.

12. The use of the carbon quantum dots according to any one of claims 1-6 or the carbon quantum dots prepared by the method according to any one of claims 7-11 in the preparation of moxibustion enhancement products.

13. The application according to claim 12, characterized in that, The moxibustion enhancement product is a composite moxibustion stick, which includes a moxa wool matrix and carbon quantum dots loaded on the moxa wool matrix. The loading amount of the carbon quantum dots is 1-5 wt% of the dry weight of the moxa wool.

14. The application according to claim 12, characterized in that, The moxibustion enhancement product is a moxibustion gel, which contains the carbon quantum dots, a gel matrix, and optional Artemisia argyi extract, wherein the concentration of the carbon quantum dots in the gel is 0.1-0.5 wt%.

15. The application according to claim 12, characterized in that, The moxibustion enhancement product is a moxibustion patch, which includes a base layer, a functional layer containing the carbon quantum dots, and an adhesive layer.

16. A composite moxibustion stick, characterized in that, include: Artemisia floss matrix; The carbon quantum dots of any one of claims 1-6 loaded on the mugwort matrix; The loading of carbon quantum dots is 1-5 wt% of the dry weight of Artemisia argyi. When the composite moxibustion stick is burned, PM2.5 emissions are reduced by more than 40% compared to ordinary moxibustion sticks that do not contain carbon quantum dots, and the time to reach 41°C at a subcutaneous depth of 5mm is shortened by more than 25% when applied to a simulated tissue phantom.

17. The composite moxibustion stick according to claim 16, characterized in that, The carbon quantum dots are loaded onto the surface of Artemisia argyi by spraying, with a spray concentration of 3-10 mg / mL and a drying temperature of 40-60℃ after spraying.

18. A moxibustion gel, characterized in that, include: The carbon quantum dots according to any one of claims 1-6 have a concentration of 0.1-0.5 wt%. The gel matrix is ​​selected from one or more of carbomer, hydroxypropyl methylcellulose, and hyaluronic acid, preferably ethylcellulose; Artemisia argyi extract; When the moxibustion gel is irradiated with 808nm near-infrared light, the surface temperature rises to 40-45℃ within 5 minutes.

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