High photo-thermal red light carbon quantum material as well as preparation method and application thereof

Abstract

The invention provides a high photo-thermal red light carbon quantum material as well as a preparation method and application thereof, and relates to the field of biological functional nano materials. The preparation method comprises the following steps: dissolving o-phenylenediamine, dopamine hydrochloride and chloroauric acid in a solvent to obtain a solution A; adding acid and an oxidizing agent into the solution A, stirring, carrying out hydrothermal reaction, and cooling to obtain a solution B; washing and centrifuging the solution B, and taking supernate to obtain a solution C; and purifying and drying the solution C to obtain the product. The preparation method is simple in synthesis condition and beneficial to industrial production. Moreover, the quantum yield is high, the fluorescence intensity is high, the photothermal effect is good, and the urease responsiveness is sensitive.

Description

Technical Field

[0001] The present invention provides a high-photothermal red-light carbon quantum material and a preparation method and application thereof, relating to the field of biofunctional nanomaterials. Background Art

[0002] Fluorescence imaging has become an important imaging technology because it can achieve real-time and non-invasive visualization of biological systems. Non-invasive means to monitor the dynamic changes of gastric pH are crucial for accurate diagnosis and treatment of gastric diseases and the development of pH-sensitive gastric drugs. Fluorescence imaging technology can be used as a simple, efficient and safe non-invasive bioimaging method to monitor the extent of changes in gastric-related diseases. Although a large number of fluorescent CDs have been developed by researchers in related fields in recent years, most of them have only short emission wavelengths.

[0003] For example, Qiaoqiao Ci et al. disclosed a novel type of iron-doped carbon dots (Fe-CDs) in "Fe-Doped Carbon Dots as NIR-II Fluorescence Probe for In Vivo Gastric Imaging and pH Detection". The preparation method is as follows: In this work, we synthesized NIR-II fluorescent Fe-doped CDs (Fe-CDs) with high QY for the first time, using dopamine hydrochloride (DA) and o-phenylenediamine (oPD) as carbon sources and FeCl3·6H2O as dopant, through a facile one-pot hydrothermal method. These unique Fe-CDs showed (1000nm) at pH 2, with linearly decreasing fluorescence intensity in response to increasing pH in the range of 2 to 6, due to gradually enhanced aggregation of the CDs (Scheme 1). Drawing on these properties in an example application, we successfully demonstrated the capability of Fe-CDs as a NIR-II fluorescent probe for in vivo detection and real-time monitoring of gastric pH changes in a mouse model, during the normal food digestion process, fasting experiments, and treatment with omeprazole drugs.

[0004] Here, we synthesize NIR-II fluorescent iron-doped CDs (Fe-CDs) for the first time using a facile one-pot thermal method using dopamine hydrochloride and o-phenylenediamine as carbon sources and FeCl₃·6H₂O as a dopant. These unique Fe-CDs exhibit fluorescence (1000 nm) at pH 2, with a linear decrease in fluorescence intensity with increasing pH from 2 to 6, attributed to the enhanced aggregation of CDs. In an example application, we successfully demonstrate the ability of Fe-CDs to serve as NIR-II fluorescent probes for detecting and real-time monitoring of gastric pH changes in a mouse model, during normal food digestion, fasting experiments, and during omeprazole drug treatment.

[0005] The researchers prepared Fe-CDs via a one-pot hydrothermal synthesis method using dopamine hydrochloride (DA) and o-phenylenediamine (oPD) as carbon sources and FeCl₃·6H₂O as a dopant. The Fe-CDs exhibited NIR-II fluorescence in acidic solutions, with a maximum absorption peak at 830 nm and an emission peak at 1000 nm. The quantum yield reached a relatively low 1.27%.

[0006] Chinese patent CN111662524B discloses a one-step hydrothermal synthesis of red fluorescent carbon dots (CFDs) from dopamine hydrochloride, o-phenylenediamine, acid, and water. The molar ratio of dopamine hydrochloride to o-phenylenediamine is 1-2:1, and the volume ratio of acid to water is 0.5-1:10. The resulting CFDs exhibit ultraviolet absorption and excitation wavelengths of 250-300 nm and 480-600 nm, respectively, with a peak emission wavelength of 600-700 nm. However, the resulting CFDs exhibit weak fluorescence intensity and insufficient tissue penetration. Summary of the Invention

[0007] To address the shortcomings of the prior art, the present invention provides a high-photothermal red-light carbon quantum material, its preparation method, and its application. The preparation method of the present invention has simple synthesis conditions, which is conducive to industrial production. Furthermore, the high-photothermal red-light carbon quantum material of the present invention has a high quantum yield, high fluorescence intensity, good photothermal effect, and sensitive urease responsiveness, demonstrating its great application prospects in the diagnosis and treatment of Helicobacter pylori in the stomach.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention provides a method for preparing a high-photothermal red-light carbon quantum material, comprising the following steps:

[0010] (1) dissolving o-phenylenediamine, dopamine hydrochloride and chloroauric acid in a solvent to obtain solution A;

[0011] (2) adding an acid and an oxidant to solution A, stirring, performing a hydrothermal reaction, and cooling to obtain solution B;

[0012] (3) Washing and centrifuging solution B, taking the supernatant to obtain solution C;

[0013] (4) Purify and dry solution C.

[0014] Furthermore, the mass ratio of o-phenylenediamine to dopamine hydrochloride is (1-2):(1-2).

[0015] Preferably, the mass ratio of o-phenylenediamine to dopamine hydrochloride is 1:(1-2).

[0016] More preferably, the mass ratio of o-phenylenediamine to dopamine hydrochloride is 1:1.

[0017] Furthermore, the mass ratio of o-phenylenediamine, chloroauric acid and oxidant in step (1) is (1-2): (0.1-0.5): (0.4-0.8).

[0018] Preferably, the mass ratio of o-phenylenediamine, metal halide and hydrogen peroxide is 1:(0.1-0.2):(0.4-0.8).

[0019] More preferably, the mass ratio of o-phenylenediamine, metal halide and hydrogen peroxide is 1:0.1:(0.4-0.8).

[0020] Furthermore, the acid in step (2) is hydrochloric acid, and the oxidant is hydrogen peroxide.

[0021] Preferably, the hydrochloric acid is concentrated hydrochloric acid.

[0022] More preferably, the mass concentration of the concentrated hydrochloric acid is 30-40%.

[0023] Furthermore, the solvent in step (1) and the solvent used for washing in step (4) are ethanol.

[0024] Preferably, the ethanol is anhydrous ethanol.

[0025] Furthermore, the temperature of the hydrothermal reaction is 150-200° C., and the reaction time is 10-14 h.

[0026] Preferably, the temperature of the hydrothermal reaction is 180-200° C., and the reaction time is 10-12 h.

[0027] Preferably, the purification is dialysis purification.

[0028] In a second aspect, the present invention provides a high-photothermal red-light carbon quantum material prepared by the above preparation method.

[0029] In a third aspect, the present invention provides the use of the high photothermal red light carbon quantum material prepared by the above preparation method in the preparation of photothermal assisted therapeutic agents.

[0030] Furthermore, the photothermal assisted therapeutic agent is irradiated by a near-infrared 808nm light source.

[0031] In a fourth aspect, the present invention provides the use of the above-mentioned high-photothermal red-light carbon quantum material in the preparation of non-invasive biological imaging probes.

[0032] In a fifth aspect, the present invention provides a fluorescent probe comprising the above-mentioned high-photothermal red-light carbon quantum material.

[0033] In a sixth aspect, the present invention provides a photothermal-assisted therapeutic agent comprising the above-mentioned high photothermal red light carbon quantum material.

[0034] The beneficial effects of the present invention are:

[0035] (1) A nanocomposite material, a highly photothermal carbon quantum dopant (CQD_A), was synthesized using o-phenylenediamine and dopamine hydrochloride as raw materials, and hydrogen peroxide and chloroauric acid as oxidants and dopants. It is responsive to the pH value of the environment and exhibits strong fluorescence in the low pH range (1-5). It is also responsive to urease, with the fluorescence intensity being correlated with the urease concentration. This material can be used to develop a formulation for the detection of gastric diseases, such as Helicobacter pylori infection, which can cause changes in the local gastric environment, and achieve in vivo precision medical imaging.

[0036] (2) The high photothermal carbon quantum material of the present invention has a certain photothermal effect, which can rise from 30°C to above 40°C within 10 minutes and can be used in photothermal assisted therapy.

[0037] Figures in the specification

[0038] Figure 1 The fluorescence intensity diagrams of samples of Example 1, Comparative Examples 1, 2, and 5 are shown.

[0039] Figure 2 This is the fluorescence intensity diagram of Comparative Example 3.

[0040] Figure 3 This is the fluorescence intensity diagram of Comparative Example 6.

[0041] Figure 4 This is a fluorescence intensity diagram of Example 1 at different pH values.

[0042] Figure 5 This is a fluorescence intensity diagram of Example 1 at different urease concentrations.

[0043] Figure 6 a in the figure is a line graph showing the relationship between Example 1 at different concentrations and the photothermal effect. Figure 6b is a line graph of the photothermal effects of Example 1 and Comparative Examples 1 and 2.

[0044] Figure 7 This is a transmission electron microscope image of Example 1.

[0045] Figure 8 This is the X-ray photoelectron spectrum of Example 1.

[0046] Figure 9 FTIR spectra of oPD, DA and Example 1. DETAILED DESCRIPTION

[0047] In order to make the technical means, creative features, purpose and effect of the present invention easy to understand, the present invention is further illustrated below in conjunction with specific embodiment, but the following embodiment is only a preferred embodiment of the present invention, not all. Based on the embodiment in the embodiment, other embodiments obtained by those skilled in the art without making creative work all fall within the protection scope of the present invention. It is worth noting that the raw materials used in the present invention are all common commercial products, and their source is not specifically limited. The technology and scientific terms used in the embodiment have the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs.

[0048] Unless otherwise specified, the concentrations described in the present invention are all mass concentrations.

[0049] The present invention does not limit the sources of the raw materials used. Unless otherwise specified, the raw materials used in the present invention are common commercial products in the technical field.

[0050] 1. Examples and Comparative Examples

[0051] Example 1 (Synthesis of CQD_A)

[0052] The specific steps of the preparation method are as follows:

[0053] 1) Disperse 0.1 g of o-phenylenediamine (oPD) and 0.1 g of dopamine hydrochloride (DA) in 20 mL of anhydrous ethanol (EtOH) and stir to fully disperse. Add 1 mL of 1% chloroauric acid (HAuCl4) dropwise to the mixture under ultrasonic agitation while stirring to obtain Solution A.

[0054] 2) Add 0.2 mL of 20% hydrogen peroxide (H2O2) and 0.1 mL of 36% concentrated hydrochloric acid to Solution B, stir rapidly until uniform, transfer to a polytetrafluoroethylene-lined container, place in a reactor, react at 180°C for 12 h, and cool to obtain Solution B;

[0055] 3) Wash solution B with anhydrous ethanol and centrifuge, and take the supernatant as solution C;

[0056] 4) Solution C was dialyzed and purified, and then freeze-dried to obtain a black powder red light-emitting carbon quantum dopant material (CQD_A), which was sealed and stored at 4°C.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that chloroauric acid is replaced by ferric chloride hexahydrate. The specific steps of the preparation method are as follows:

[0059] 1) Disperse 0.1 g of o-phenylenediamine (oPD) and 0.1 g of dopamine hydrochloride (DA) in 20 mL of anhydrous ethanol (EtOH) and stir to fully disperse. Dissolve 0.05 g of ferric chloride hexahydrate (FeCl3·6H2O) in 5 mL of anhydrous ethanol and add dropwise ultrasonic dispersion under stirring to obtain solution A.

[0060] 2) Add 0.2 mL of 20% hydrogen peroxide (H2O2) and 0.1 mL of 36% concentrated hydrochloric acid to Solution B, stir rapidly until uniform, transfer to a polytetrafluoroethylene-lined container, place in a reactor, react at 180°C for 12 h, and cool to obtain Solution B;

[0061] 3) Wash solution B with anhydrous ethanol and centrifuge it to take the supernatant solution C

[0062] 4) Solution C was dialyzed and purified to obtain a black powder, Comparative Example 1, which was sealed and stored at 4°C.

[0063] Comparative Example 2

[0064] The difference from Example 1 is that chloroauric acid is not added. The specific steps of the preparation method are as follows:

[0065] 1) Disperse 0.1 g of o-phenylenediamine (oPD) and 0.1 g of dopamine hydrochloride (DA) in 20 mL of anhydrous ethanol (EtOH) and stir to fully disperse to obtain solution A;

[0066] 2) Add 0.2 mL of 20% hydrogen peroxide (H2O2) and 0.1 mL of 36% concentrated hydrochloric acid to Solution B, stir rapidly until uniform, transfer to a polytetrafluoroethylene-lined container, place in a reactor, react at 180°C for 12 h, and cool to obtain Solution B;

[0067] 3) Wash solution B with anhydrous ethanol and centrifuge it to take the supernatant solution C

[0068] 4) Solution C was dialyzed and purified to obtain a black powder, Comparative Example 2, which was sealed and stored at 4°C.

[0069] Comparative Example 3

[0070] The difference from Example 1 is that the amount of 1% chloroauric acid added is different, namely 0, 0.5, 1.0, 1.5, and 2.0 mL, respectively.

[0071] Comparative Example 4

[0072] The difference from Example 1 is that H2O2 and chloroauric acid are not added. The specific steps of the preparation method are as follows:

[0073] 1) Disperse 0.1 g of o-phenylenediamine (oPD) and 0.1 g of dopamine hydrochloride (DA) in 20 mL of anhydrous ethanol (EtOH) and stir to fully disperse to obtain solution A;

[0074] 2) Add 0.1 mL of 36% concentrated hydrochloric acid to Solution B, stir rapidly until uniform, transfer to a polytetrafluoroethylene-lined container, place in a reactor, react at 180°C for 12 h, and cool to obtain Solution B;

[0075] 3) Wash solution B with anhydrous ethanol and centrifuge it to take the supernatant solution C

[0076] 4) Solution C was dialyzed and purified to obtain a black powder, Comparative Example 4, which was sealed and stored at 4°C.

[0077] Comparative Example 5

[0078] The difference from Example 1 is that chloroauric acid is replaced by copper chloride. The specific steps of the preparation method are as follows:

[0079] 1) Disperse 0.1 g of o-phenylenediamine (oPD) and 0.1 g of dopamine hydrochloride (DA) in 20 mL of anhydrous ethanol (EtOH) and stir to fully disperse. Add 0.05 g of copper chloride (CuCl2) dropwise to the mixture under ultrasonic vibration while stirring to obtain solution A.

[0080] 2) Add 0.2 mL of 20% hydrogen peroxide (H2O2) and 0.1 mL of 36% concentrated hydrochloric acid to Solution B, stir rapidly until uniform, transfer to a polytetrafluoroethylene-lined container, place in a reactor, react at 180°C for 12 h, and cool to obtain Solution B;

[0081] 3) Wash solution B with anhydrous ethanol and centrifuge it to take the supernatant solution C

[0082] 4) Solution C was dialyzed and purified to obtain a black powder, Comparative Example 5, which was sealed and stored at 4°C.

[0083] Comparative Example 6

[0084] The difference from Example 1 is that the amount of H2O2 added is different, namely 0, 0.1, 0.15, 0.2, and 0.25 mL, respectively.

[0085] 2. Effect Examples

[0086] 1. Example 1 and Comparative Examples 1-6 were dissolved in deionized water and ultrasonically dispersed in a test tube at the same concentration of 1 μg / mL to prepare a solution with pH = 2. The solution was tested using a fluorescence spectrophotometer and the average of three test results was taken. The results are as follows: Figure 1-3 .

[0087] Depend on Figure 1 It can be seen that, by comparing the samples synthesized with different synthetic raw materials in Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 5, the fluorescence intensity of the sample of Example 1 prepared by adding 1% chloroauric acid (HAuCl4) is stronger at 620nm / 680nm, the fluorescence intensity of Comparative Example 1 by adding ferric chloride hexahydrate (FeCl3·6H2O) is weaker than that of Example 1, the fluorescence intensity of Comparative Example 2 by not adding any metal halide is weaker, and the fluorescence intensity of Comparative Example 5 by adding copper chloride (CuCl2) is the weakest, indicating that the introduction of chloroauric acid (HAuCl4) as a dopant can enhance the red fluorescence emission intensity.

[0088] like Figure 2 It can be seen that when the addition amount of 1% HAuCl4 and H2O2 is 0 mL, the fluorescence intensity of the prepared sample is the smallest. After adding H2O2, the fluorescence intensity is significantly enhanced.

[0089] As the amount of 1% HAuCl₄ added increases, the fluorescence intensity of the sample gradually increases. When the amount added exceeds 1.5 mL, the fluorescence intensity of the sample approaches a constant value. This indicates that the introduction of chloroauric acid as a dopant undergoes a coordination reaction with the raw materials, oPD and DA. The oxidizing agent, H₂O₂, promotes the formation of Schiff base polymers. Together, these two factors promote the formation of more CQD_A with red emission.

[0090] like Figure 3 It can be seen that when the amount of H2O2 added is 0 mL, the fluorescence intensity of the prepared sample is the smallest. After adding H2O2, the fluorescence intensity is significantly enhanced.

[0091] As the amount of H2O2 added increases, the fluorescence intensity of the sample gradually increases. When the amount added is greater than 0.2 mL, the fluorescence intensity of the sample tends to a certain value. Therefore, the optimal amount of H2O2 added is 0.2 mL.

[0092] 2. Quantum yield

[0093] Using the fluorescent dye Rhodamine B dissolved in water as a reference, absorbance and fluorescence intensity measurements were performed on a 10 μg / mL aqueous solution prepared in Example 1 and a 4 μg / mL aqueous solution of Rhodamine B at room temperature. The maximum absorption peak of Rhodamine B was found to be at 550 nm, and the fluorescence intensity peak was at approximately 580 nm. Substituting into the formula:

[0094] QY=QYB ×I×A B ×n 2 / (I B ×A×(n B ) 2 )

[0095] QY and QY B are the fluorescence quantum yields of Example 1 and Rhodamine B, respectively. B are the integrated fluorescence intensities of Example 1 and Rhodamine B, respectively. A and A B are the UV-visible absorption intensities of the sample and Rhodamine B, respectively. n is the refractive index of the solvent.

[0096] 3. Urease responsiveness detection

[0097] 1) The powder of Example 1 was dissolved in deionized water to prepare a solution with a concentration of 1 μg / mL;

[0098] 2) Dissolve urease in deionized water to prepare urease solutions with concentrations of 10, 20, 30, and 40 μg / mL;

[0099] 3) 1 mL of urease solution and 2 mL of the solution of Example 1 were mixed with a small amount of hydrochloric acid to adjust the pH of the mixed solution, maintained at 37° C. for 15 minutes, and the fluorescence spectrum of the mixed solution was measured using a fluorescence spectrophotometer. The average of the three test results was taken;

[0100] The pH values of the solutions are 1, 2, 3, 4, 5, and 6, respectively.

[0101] like Figure 4 The fluorescence intensity of Example 1 is the highest at pH = 1, and gradually decreases with the increase of pH value. Fluorescence quenching occurs when pH > 6. There is a good linear relationship between fluorescence intensity and pH value (R 2 =0.968). This indicates that Example 1 has a sensitive response to the environmental pH value.

[0102] like Figure 5 As the urease concentration increases, the fluorescence intensity gradually decreases and tends to a certain value when the urease concentration is ≥30μg / mL. There is a good linear relationship between the fluorescence intensity and the urease concentration (R 2 =0.897). The fluorescence properties of Example 1 have a certain responsiveness to urease.

[0103] 4. Photothermal effect detection

[0104] 1) The powder of Example 1 was dissolved in deionized water to prepare solutions with concentrations of 250, 500, and 750 μg / mL;

[0105] 2) 3 mL of the solution of Example 1 of different concentrations were placed in test tubes and irradiated with a near-infrared 808 nm light source at room temperature (27°C);

[0106] 3) Record the solution temperature every 2 minutes using a thermal imager.

[0107] Figure 6 a shows four groups of Example 1 solutions with different concentrations, namely 0, 250, 500, and 750 μg / mL, where 0 μg / mL is the same volume of deionized water. The temperature changes of the Example 1 solutions after irradiation with a near-infrared 808 nm light source.

[0108] The temperatures of Example 1 solutions of varying concentrations increased with increasing illumination time. Under near-infrared 808nm light, the temperature of a 750μg / mL solution of Example 1 rose by 10°C within 10 minutes, demonstrating the excellent photothermal effect of this red-light carbon quantum material. The higher the concentration, the faster the temperature rise after illumination, indicating a correlation between the material's photothermal effect and concentration.

[0109] Figure 6 b shows the temperature changes of the solutions of Example 1, Comparative Example 1, and Comparative Example 2 at 750 μg / mL, where 0 μg / mL is the same volume of deionized water.

[0110] After the solution of Example 1 was irradiated with light, the temperature rising rate was the largest, while the temperature rising rate of Comparative Example 2 was the smallest. The temperature rising rate of the solution of Comparative Example 1 was slower than that of Example 1. This shows that the introduction of the metal-carbon hybrid system significantly enhanced the photothermal performance of the carbon quantum material by regulating the electronic structure, and the introduction of Au 3+ Than the introduction of Fe 3+ The effect is better.

[0111] 5. Transmission electron microscopy (TEM) image display and X-ray photoelectron spectroscopy were performed on Example 1, and FTIR spectrum detection was performed on Example 1, oPD and DA.

[0112] like Figure 7 Transmission electron microscopy (TEM) images show that the average size of the nanocomposite material is about 60nm, and the structure is regular and uniform. This indicates that the quinone structure generated by oxidation of DA reacts with oPD to form Schiff base compounds, which react with Au 3+ After complexation, COF_A was further assembled and carbonized and dehydrated after hydrothermal reaction, maintaining the corresponding structure. This structure may make it responsive to urease.

[0113] like Figure 8The surface of the sample in Example 1 mainly contains C (75.17%), and a small amount of O (10.01%), N (13.18%), and Cl (1.64%). The peak at 284.8 eV is derived from graphite carbon (CC / C=C, sp 2 ), the peak at ~287.5eV is derived from C=O. This indicates that CQD_A has a highly conjugated carbon skeleton and a graphitized structure. The peak at ~398.5eV is derived from pyridinic nitrogen (or phenazine nitrogen), sp 2 Hybridized lone pair electrons, ~400.0 eV, originate from pyrrolic nitrogen, sp 2 Hybridized NH, ~401.5 eV originates from sp 3 Hybridization. The peaks at 530-531eV and 532.5eV originate from C=O and C-OH / COC, respectively. Literature review indicates that the presence of C=O and graphitic N functional groups enables CQD_A to emit red fluorescence. The presence of pyrrolic and pyridinic nitrogen indicates that DA undergoes oxidative polymerization, producing oligomers with pyrrole and pyridinic ring structures.

[0114] like Figure 9 It can be seen that 1616cm -1 and 1465cm -1 The absorption peak at 740 cm -1 and 590cm -1 There is an obvious absorption peak at 1035cm -1 The peak at 3400 cm can be attributed to the secondary amine functional group. The presence of phenazine structures and some unreacted amino functional groups on the surface of CQD_A indicates that o-phenylenediamine has been oxidatively polymerized to form a dimer. -1- 2830cm -1 are attributed to the NH and –OH stretching vibrations, respectively.

[0115] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a high-photothermal red-light carbon quantum material, characterized in that: The following steps are involved: (1) dissolving o-phenylenediamine, dopamine hydrochloride and chloroauric acid in a solvent to obtain solution A; (2) adding an acid and an oxidant to solution A, stirring, performing a hydrothermal reaction, and cooling to obtain solution B; (3) Washing and centrifuging solution B, taking the supernatant to obtain solution C; (4) Purify and dry solution C.

2. The preparation method according to claim 1, characterized in that The mass ratio of o-phenylenediamine to dopamine hydrochloride is (1-2): (1-2); the mass ratio of o-phenylenediamine, chloroauric acid and oxidant in step (1) is (1-2): (0.1-0.5): (0.4-0.8).

3. The preparation method according to claim 1, characterized in that The acid in step (2) is hydrochloric acid, and the oxidant is hydrogen peroxide.

4. The preparation method according to claim 1, characterized in that The temperature of the hydrothermal reaction is 150-200° C., and the reaction time is 10-14 hours.

5. The preparation method according to claim 1, characterized in that The solvent in step (1) and the solvent used for washing in step (4) are ethanol.

6. A high-photothermal red-light carbon quantum material prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the high-photothermal red-light carbon quantum material prepared by the preparation method according to any one of claims 1 to 5 and / or the high-photothermal red-light carbon quantum material according to claim 6 in the preparation of a photothermal-assisted therapeutic agent.

8. Use of the high-photothermal red-light carbon quantum material prepared by the preparation method according to any one of claims 1 to 5 and / or the high-photothermal red-light carbon quantum material according to claim 6 in the preparation of non-invasive biological imaging probes.

9. A fluorescent probe, characterized in that The invention comprises the high-photothermal red-light carbon quantum material prepared by the preparation method according to any one of claims 1 to 5 and / or the high-photothermal red-light carbon quantum material according to claim 6.

10. A photothermal assisted therapy agent, characterized in that: The invention comprises the high-photothermal red-light carbon quantum material prepared by the preparation method according to any one of claims 1 to 5 and / or the high-photothermal red-light carbon quantum material according to claim 6.

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