A water-soluble room temperature phosphorescent microsphere material and its preparation method and use

Abstract

The present invention discloses a water-soluble room temperature phosphorescent microsphere material, its preparation method and use. The preparation method comprises: reacting an organic acid with an organic amine by microwaves to obtain a phosphorescent carbon dot material; and reacting a first mixed reaction system comprising hexadecyltrimethylammonium bromide, triethylamine and the phosphorescent carbon dot material, and then adding a silicon source to continue the reaction to obtain a water-soluble room temperature phosphorescent microsphere material; or reacting hexadecyltrimethylammonium bromide with triethylamine, and then adding the phosphorescent carbon dot material and a silicon source to continue the reaction to obtain a water-soluble room temperature phosphorescent microsphere material. The water-soluble room temperature phosphorescent microsphere material prepared by the present invention has a dendritic mesoporous shape, is uniform in size, and has significant and bright phosphorescence emission under aqueous conditions; at the same time, the successful preparation of the material is expected to solve the common problems of existing carbon dot-based aqueous room temperature phosphorescent materials, such as easy quenching and easy cross-linking and agglomeration, and promote its application in the biomedical field.

Description

Technical Field

[0001] The present invention belongs to the technical field of phosphorescent materials, and in particular relates to a water-soluble room temperature phosphorescent microsphere material and a preparation method and application thereof. Background Art

[0002] Phosphorescent materials are widely used and highly promising luminescent materials. Like fluorescence, they belong to the photoluminescence phenomenon, but phosphorescence has a much longer lifetime and a larger Stokes shift, making it a research hotspot in the field of luminescent materials. Despite these advantages, phosphorescence's luminescence intensity is highly susceptible to temperature and oxygen, making materials capable of emitting phosphorescent light at room temperature extremely important. Room-temperature phosphorescent materials, a class of materials that exhibit long-lived, persistent luminescence at room temperature, have broad applications in areas such as information encryption, anti-counterfeiting, and bioimaging. Existing phosphorescent materials primarily include rare earth-based luminescent materials, noble metal complexes, and pure organic compounds. However, most of these materials suffer from disadvantages such as poor processing, high cost, and high metal toxicity, limiting their synthesis and application. Metal-free carbon-based room-temperature phosphorescent materials, on the other hand, offer numerous advantages, including long-lived phosphorescent emission, excellent optical properties such as a large Stokes shift, simple synthesis, low cost, and good biocompatibility. Therefore, the development of new non-metallic carbon-based, long-lasting luminescence materials is a current research hotspot and trend.

[0003] However, most carbon-based phosphorescent materials can only achieve phosphorescent emission in the solid state. This is because oxygen, as one of the most effective triplet quenchers, can lead to a decrease in phosphorescence quantum yield and a shortened lifetime. Therefore, in the aqueous phase, it is extremely susceptible to the influence of water molecules and dissolved oxygen, resulting in significant quenching of phosphorescence, which greatly affects its application in the biological field. In addition, the existing aqueous carbon dot-SiO1 composite phosphorescent microspheres are prone to cross-linking and have irregular morphology, which seriously restricts their application research in the fields of food environmental analysis, biomedicine, etc. (such as biochemical sensing, immunochromatography, bioimaging, etc.). Therefore, the development of a preparation method for carbon dot-SiO2 composite phosphorescent microspheres with uniform size and regular morphology is still facing challenges. Summary of the Invention

[0004] The main purpose of the present invention is to provide a water-soluble room temperature phosphorescent microsphere material and its preparation method and use, so as to overcome the shortcomings of the prior art.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0006] An embodiment of the present invention provides a method for preparing a water-soluble room temperature phosphorescent microsphere material, which comprises:

[0007] The organic acid and the organic amine are subjected to a microwave reaction to obtain a phosphorescent carbon dot material; wherein the microwave reaction causes at least one or more functional groups of hydroxyl, carboxyl, and amino to be distributed on the surface of the phosphorescent carbon dot material;

[0008] Also, a first mixed reaction system comprising cetyltrimethylammonium bromide (CTAB), triethylamine (TEA) and the phosphorescent carbon dot material is reacted, and then a silicon source is added to continue the reaction to obtain a water-soluble room temperature phosphorescent microsphere material; or, cetyltrimethylammonium bromide is reacted with triethylamine, and then the phosphorescent carbon dot material and a silicon source are added to continue the reaction to obtain a water-soluble room temperature phosphorescent microsphere material.

[0009] The present invention also provides a water-soluble room temperature phosphorescent microsphere material prepared by the aforementioned preparation method, wherein the water-soluble room temperature phosphorescent microsphere material comprises dendritic mesoporous silicon and phosphorescent carbon dot material dispersed within the carbon-oxygen skeleton and pores of the dendritic mesoporous silicon by chemical bonds.

[0010] The embodiments of the present invention also provide uses of the aforementioned water-soluble room temperature phosphorescent microsphere material in biomedical analysis, environmental monitoring, and food safety analysis.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The water-soluble room temperature phosphorescent microsphere material (water-soluble CDs@DMSN room temperature phosphorescent microsphere material) provided by the present invention has convenient preparation conditions, is green and environmentally friendly, and has low cost;

[0013] (2) The preparation method of the water-soluble room temperature phosphorescent microsphere material provided by the present invention is simple. The CDs are successfully confined in a stable nanostructure constructed by silicon and oxygen using a one-step synthesis method in the preparation process of dendritic mesoporous silica (DMSN), realizing the phosphorescence phenomenon in the aqueous phase.

[0014] (3) The water-soluble room temperature phosphorescent microsphere material prepared by the present invention has a dendritic mesoporous distribution of particles in aqueous solution, which may solve the problem of easy aggregation or irregular distribution of particles in aqueous phase, and provide new research ideas for further application in the biological field;

[0015] (4) The raw materials used in the preparation method provided by the present invention are green and environmentally friendly, low in cost, and the preparation method is simple and can be produced on a large scale, which will have good application value in actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 Schematic diagram of afterglow of a water-soluble room temperature phosphorescent microsphere material in an aqueous phase according to a typical embodiment of the present invention;

[0018] Figure 2a 、 Figure 2c This is an electron microscope image of the dendritic mesoporous silicon of Example 1 of the present invention;

[0019] Figure 2b 、 Figure 2d is an electron microscope image of the water-soluble CDs@DMSN room temperature phosphorescent microsphere material in Example 1 of the present invention;

[0020] Figure 3 IR spectra of CDs, DMSN, and water-soluble CDs@DMSN room temperature phosphorescent microsphere materials in Example 1 of the present invention;

[0021] Figure 4 1 is the TGA graph of CDs, DMSN, and water-soluble CDs@DMSN room temperature phosphorescent microsphere materials in Example 1 of the present invention;

[0022] Figure 5 : This is the potential diagram of CDs, DMSN, and water-soluble CDs@DMSN room temperature phosphorescent microsphere materials in Example 1 of the present invention;

[0023] Figure 6a-6b The fluorescence emission spectrum and phosphorescence emission spectrum of the water-soluble CDs@DMSN room temperature phosphorescent microsphere material prepared in Example 1 of the present invention at different excitation wavelengths;

[0024] Figure 7 The phosphorescence lifetime decay curve and fitting curve of the water-soluble CDs@DMSN room temperature phosphorescent microsphere material prepared in Example 1 of the present invention;

[0025] Figure 8 Schematic diagram of the water-soluble CDs@DMSN room temperature phosphorescent microsphere material prepared in Example 1 of the present invention under sunlight, 365nm ultraviolet irradiation, and after being turned off;

[0026] Figure 9 This is the solid-state phosphorescence lifetime spectrum of CDs powder in Comparative Example 3 of the present invention. DETAILED DESCRIPTION

[0027] In view of the defects of the existing technology, the inventors of this case have proposed the technical solution of the present invention after long-term research and extensive practice. The main method is to chemically bond a large number of phosphorescent carbon dot materials (CDs) with any one or more functional groups of hydroxyl, carboxyl, and amino groups distributed on the surface with a single large-pore mesoporous nanomaterial to achieve an effective method of phosphorescent emission in an aqueous phase. This method has good uniformity, controllable process and good dispersibility. The dendritic mesoporous silica nanoparticles (DMSNs) have a central radial pore structure, and have the advantages of large specific surface area, good optical transmittance, and easy functionalization.

[0028] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Specifically, as one aspect of the technical solution of the present invention, a method for preparing a water-soluble room temperature phosphorescent microsphere material includes:

[0030] The organic acid and the organic amine are subjected to a microwave reaction to obtain a phosphorescent carbon dot material (denoted as CDs); wherein the microwave reaction causes at least one or more functional groups of hydroxyl, carboxyl, and amino to be distributed on the surface of the phosphorescent carbon dot material;

[0031] Also, a first mixed reaction system comprising cetyltrimethylammonium bromide (CTAB), triethylamine (TEA) and the phosphorescent carbon dot material is reacted, and then a silicon source is added to continue the reaction to obtain a water-soluble room-temperature phosphorescent microsphere material; or, cetyltrimethylammonium bromide is reacted with triethylamine, and then the phosphorescent carbon dot material and a silicon source are added to continue the reaction to obtain a water-soluble room-temperature phosphorescent microsphere material (denoted as: water-soluble CDs@DMSN room-temperature phosphorescent microsphere material).

[0032] In some preferred embodiments, the preparation method specifically comprises: mixing an organic acid, an organic amine and a solvent and performing a microwave reaction, followed by purification to obtain the phosphorescent carbon dot material.

[0033] Furthermore, the organic acid includes phosphoric acid and / or lysine, but is not limited thereto.

[0034] Furthermore, the organic amine includes any one or a combination of two or more of ethanolamine, ethylenediamine, polyethyleneimine, and polyetherimide, but is not limited thereto.

[0035] Furthermore, the solvent includes water, but is not limited thereto.

[0036] Furthermore, the molar ratio of the organic acid to the organic amine is 20:1 to 50:1.

[0037] Furthermore, the purification treatment includes dialysis and / or filtration, but is not limited thereto.

[0038] In some preferred embodiments, the preparation method specifically comprises:

[0039] allowing a first mixed reaction system comprising hexadecyltrimethylammonium bromide, triethylamine, the phosphorescent carbon dot material, and water to react at room temperature for 1 to 3 hours to obtain a first intermediate product;

[0040] Furthermore, a silicon source is added to the first intermediate product and refluxed at 60° C. to 80° C. for 20 to 30 hours. The obtained product is then centrifuged and washed to obtain a water-soluble room temperature phosphorescent microsphere material.

[0041] In some preferred embodiments, the preparation method specifically comprises:

[0042] Stirring an aqueous solution containing hexadecyltrimethylammonium bromide and triethylamine at room temperature for 1 to 2 hours to obtain a template;

[0043] Furthermore, phosphorescent carbon dot material and silicon source are added to the template and refluxed at 60-80° C. for 20-30 hours. The obtained product is then centrifuged and washed to obtain a water-soluble room temperature phosphorescent microsphere material.

[0044] Furthermore, the centrifugal treatment has a rotation speed of 8000 to 12000 r / min and a time of 5 to 15 minutes.

[0045] Furthermore, the washing treatment is at least used to treat excess unreacted raw materials.

[0046] Furthermore, the water-soluble room temperature phosphorescent microsphere material is stored in ethanol.

[0047] In some preferred embodiments, the silicon source includes tetraethyl orthosilicate (TEOS), but is not limited thereto.

[0048] In some preferred embodiments, the silicon source includes tetraethyl orthosilicate and an oil phase solvent, wherein the oil phase solvent includes any one of cyclohexane and n-hexane or a combination of two or more thereof, and is not limited thereto.

[0049] Furthermore, the concentration of tetraethyl orthosilicate in the silicon source is 0.5-2 mol / L.

[0050] Furthermore, the dropping speed of the silicon source is 0.110.5 ml / min.

[0051] In some preferred embodiments, the usage ratio of the phosphorescent carbon dot material, hexadecyltrimethylammonium bromide, triethylamine and silicon source is 0.02-2 g: 0.1-2 g: 0.01-1 g: 1-10 ml.

[0052] In some more specific embodiments, the water-soluble room temperature phosphorescent microsphere material is formed by connecting phosphorescent carbon dots to a matrix by chemically bonding with silicon dioxide during the preparation of dendritic mesoporous silicon, and the preparation process is simple. Specifically, the preparation method of the water-soluble room temperature phosphorescent microsphere material includes:

[0053] (1) A brown gel-like crude product is obtained by microwave treatment of ethanolamine and phosphoric acid solution. The crude product is dissolved in water, sonicated, dialyzed, and freeze-dried or heated to obtain a yellow powder (CDs);

[0054] (2) adding 0.02-2 g of the carbon dot powder CDs in step (1) to a reaction solution of 0.1-2 g of CTAB and 0.01-1 g of TEA, and then adding 10-50 ml of water, and reflux reaction for 1-2 h, wherein the reflux reaction temperature is 20-75 ° C and the stirring speed is 80-300 rpm;

[0055] (3) After one hour of reaction, a cyclohexane solution of TEOS was added to the mixed solution of step (2), wherein 1 to 10 ml of TEOS and 5 to 20 ml of cyclohexane were added, and the mixture was refluxed for 20 to 30 hours at a stirring speed of 80 to 300 rpm and a temperature of 60 to 80°C.

[0056] (4) The mixed solution containing CDs obtained from the reflux reaction in step 3 is allowed to stand until it reaches room temperature. After separation, the upper layer is removed to obtain a milky yellow-white substance in the lower layer. The lower layer is washed with deionized water and anhydrous ethanol 2 to 4 times to remove excess CDs and unreacted raw material small molecules. Finally, the obtained product is dispersed in anhydrous ethanol.

[0057] In the present invention, during the reflux reaction, phosphorescent carbon dots (CDs) with any one or more functional groups among hydroxyl, carboxyl, and amino groups distributed on the surface are chemically bonded to silica, thereby fixing the CDs inside the silica cross-linked network, stabilizing their excited triplet state, and achieving phosphorescent emission.

[0058] The present invention utilizes mesoporous silicon as a template, and its morphology and size are uniform. After in-situ composite carbon dots, it can solve the problems of existing carbon dot-based aqueous phosphorescent microspheres, such as severe cross-linking and uncontrollable morphology. At the same time, compared with rare earth metal complexes and organic phosphorescent materials, the preparation process of the present invention is simpler and more convenient, and aqueous room temperature phosphorescence can be achieved in one step. The emission lifetime is longer, reaching 1.195 seconds, which can be seen by the naked eye as 8 seconds.

[0059] Another aspect of an embodiment of the present invention further provides a water-soluble room temperature phosphorescent microsphere material obtained by the aforementioned preparation method, wherein the water-soluble room temperature phosphorescent microsphere material includes dendritic mesoporous silicon (denoted as: DMSN) and a phosphorescent carbon dot material dispersed inside the dendritic mesoporous silicon skeleton and in the pores by chemical bonds.

[0060] Furthermore, the phosphorescent carbon dot material is mostly dispersed inside the dendritic mesoporous silicon skeleton by chemical bonds, and a small part is located in the pores.

[0061] The dendritic mesoporous silicon in the present invention is dendritic mesoporous silicon dioxide nanoparticles.

[0062] In some preferred embodiments, the mass ratio of the phosphorescent carbon dot material to the dendritic mesoporous silicon in the water-soluble room temperature phosphorescent microsphere material is 1:50 to 10:50.

[0063] In some preferred embodiments, the particle size of the phosphorescent carbon dot material is below 10 nm.

[0064] In some preferred embodiments, the particle size of the dendritic mesoporous silica is 50-300 nm.

[0065] In some preferred embodiments, the pore diameter of the dendritic mesoporous silica is 3 to 25 nm.

[0066] In some preferred embodiments, the phosphorescent carbon dot material has a phosphorescent emission wavelength of 400 to 500 nm.

[0067] In some preferred embodiments, the phosphorescence emission wavelength of the water-soluble room temperature phosphorescent microsphere material is the same as the emission wavelength of the phosphorescent carbon dot material.

[0068] In some preferred embodiments, the phosphorescence emission wavelength of the water-soluble room temperature phosphorescent microsphere material is in the range of 400 to 500 nm.

[0069] In some preferred embodiments, the solid state of the water-soluble room temperature phosphorescent microsphere material exhibits bright phosphorescence at room temperature.

[0070] In some preferred embodiments, the water-soluble room temperature phosphorescent microsphere material exhibits phosphorescence in water or ethanol phase.

[0071] Another aspect of the embodiments of the present invention further provides uses of the aforementioned water-soluble room temperature phosphorescent microsphere material in biomedical analysis, environmental monitoring, and food safety analysis.

[0072] Another aspect of the embodiments of the present invention further provides the use of the aforementioned water-soluble room temperature phosphorescent microsphere material in food environmental analysis or biomedicine.

[0073] For example, applications in biochemical sensing, immunochromatography, bioimaging, etc.

[0074] The water-soluble CDs@DMSN room-temperature phosphorescent microspheres prepared in the present invention have a dendritic mesoporous shape, uniform size, and exhibit significant and bright phosphorescence emission under aqueous conditions. At the same time, the successful preparation of the water-soluble CDs@DMSN room-temperature phosphorescent microspheres is expected to solve the common problems of existing carbon dot-based aqueous room-temperature phosphorescent materials, such as easy quenching and easy cross-linking and agglomeration, and promote their widespread application in biomedical fields such as biochemical sensing analysis, bioimaging, and disease diagnosis and treatment.

[0075] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0076] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0077] Example 1: Preparation using ethanolamine and phosphoric acid as raw materials (preparation of mesoporous silicon by oil-water two-phase separation method, carbon dots containing amino, hydroxyl and phosphoric acid groups)

[0078] 1-4 ml of ethanolamine and 2-16 ml of phosphoric acid were added to 10-20 ml of water and microwaved at 700 W for 2-7 minutes. After cooling to room temperature, the mixture solidified into a dark brown gel-like solid. Dissolved in deionized water, the solution was neutralized to pH 7 with a weak base (Na2CO3), filtered through a membrane and dialyzed with a 1000 Da molecular weight cutoff. Freeze-dried or heat-dried, the resulting mixture yielded a yellow powder. 0.1-2 g of CTAB, 0.01-1 g of TEA, and 0.02-2 g of CDs powder were added to 10-50 ml of water and refluxed for 1-2 hours at a temperature of 20-75°C and a stirring speed of 80-300 rpm. A cyclohexane solution of TEOS (1-10 ml of TEOS and 5-20 ml of cyclohexane) was then added to the reaction system. The mixture was then refluxed for 20-30 hours at 60-80°C and a stirring speed of 80-300 rpm. After the reflux reaction is completed, the mixed solution containing CDs obtained by the reflux reaction is allowed to stand and cool to room temperature. After separation, the upper layer is removed to obtain a milky yellow-white substance in the lower layer. The lower layer is washed three times with deionized water and anhydrous ethanol to remove excess CDs and unreacted raw material small molecules. Finally, the obtained product is dispersed in deionized water to obtain water-soluble CDs@DMSN room temperature phosphorescent microsphere material.

[0079] (1) Performance characterization.

[0080] The electron microscope image of the dendritic mesoporous silicon prepared in this example is as follows Figure 2a 、 Figure 2c As shown; the electron microscope image of the water-soluble CDs@DMSN room temperature phosphorescent microsphere material prepared in this embodiment is as shown Figure 2b 、 Figure 2d shown by Figure 2a-2d It can be seen that the prepared water-soluble CDs@DMSN room temperature phosphorescent microspheres have uniform size and present a dendritic spherical structure. The overall reaction process does not change the original morphology of DMSN. Figure 3 and Figure 4 They are the infrared images and thermogravimetric analysis images of CDs, DMSN and water-soluble CDs@DMSN room temperature phosphorescent microspheres. Figure 5 The three figures show that CDs and DMSN are effectively combined, and there are changes in the corresponding groups or characteristics. The fluorescence emission spectrum and phosphorescence emission spectrum of the water-soluble CDs@DMSN room temperature phosphorescent microspheres prepared in this example are shown in Figure 2. Figure 6a-6b , and its life decay diagram is Figure 7 The corresponding states under sunlight, 365nm ultraviolet light and after being turned off are as follows Figure 8 As shown, the prepared water-soluble CDs@DMSN room temperature phosphorescent microsphere material is observed to be translucent white under sunlight, blue under ultraviolet light, and green after the UV light is turned off. After irradiation with UV light, the water-soluble CDs@DMSN room temperature phosphorescent microsphere material prepared in this example has an afterglow that lasts for 6 to 15 seconds. The lifetime calculated by fitting the luminescence decay curve is 1.195 seconds.

[0081] Example 2: Using ethanolamine and phosphoric acid as raw materials (anion-assisted preparation of mesoporous silicon, carbon dots containing amino, hydroxyl, and phosphoric acid groups)

[0082] 1-4 ml of ethanolamine and 2-16 ml of phosphoric acid were added to 10-20 ml of water and microwaved at 700 W for 2-7 minutes. After cooling to room temperature, the solidified product solidified into a dark brown gel-like solid. After dissolving in deionized water, the solution was neutralized with a weak base (Na2CO3) to a pH of 7. The solution was then filtered through a membrane with a molecular weight cutoff of 1000 Da and dialyzed. A yellow powder was obtained by freeze-drying or heat-drying. 0.01-0.1 g of TEA was added to 10-50 ml of water. After incubating in an oil bath at 60-100°C for 20-40 minutes, 0.1-0.5 g of CTAB and 0.1-0.5 g of NaSal were added and the reaction was continued under reflux for 1-2 hours. The reflux reaction temperature was 60-100°C and the stirring speed was 80-300 rpm. 1-10 mL of TEOS solution is then added to the reaction system, followed by a reflux reaction at 60-80°C for 1-4 hours with stirring at 80-300 rpm. After reflux, the resulting mixed solution containing CDs is allowed to cool to room temperature. The solution is then washed three times with deionized water and then with anhydrous ethanol to remove excess CDs and unreacted starting small molecules. Finally, the resulting product is dispersed in deionized water to yield water-soluble CDs@DMSN room-temperature phosphorescent microspheres.

[0083] Example 3: Preparation using phosphoric acid and ethylenediamine as raw materials (preparation of mesoporous silicon by oil-water two-phase separation method, carbon dots containing amino and phosphoric acid groups)

[0084] 0.1-1g of phosphoric acid and 0.5-2ml of ethylenediamine are added to 40-100ml of water and hydrothermally reacted at 200°C for 5-10 hours. After cooling to room temperature, the mixture is filtered and dialyzed using a 3000Da molecular weight cutoff. Freeze-dried or heat-dried to obtain a yellow-white powder. 0.1-2g of CTAB, 0.01-1g of TEA, and 0.02-2g of PCDs powder are added to 10-50ml of water and refluxed for 1-2 hours at a temperature of 20-75°C and a stirring speed of 80-300rpm. A cyclohexane solution of TEOS (1-10ml of TEOS and 5-20ml of cyclohexane) is then added to the reaction system and refluxed for 20-30 hours at 60-80°C with a stirring speed of 80-300rpm. After the reflux reaction is completed, the mixed solution containing CDs obtained by the reflux reaction is allowed to stand and cool to room temperature. After separation, the upper layer is removed to obtain a milky yellow-white substance in the lower layer. The lower layer is washed three times with deionized water and anhydrous ethanol to remove excess CDs and unreacted raw material small molecules. Finally, the obtained product is dispersed in deionized water to obtain water-soluble CDs@DMSN room temperature phosphorescent microsphere material.

[0085] Example 4: Preparation using lysine and polyethyleneimine as raw materials (preparation of mesoporous silicon by oil-water two-phase separation method, carbon dots containing amino, hydroxyl and carboxyl groups)

[0086] 0.1-1 g of lysine and 0.5-2 ml of polyethyleneimine were added to 40-100 ml of water and hydrothermally reacted at 200°C for 5-10 hours. After cooling to room temperature, the mixture was filtered and dialyzed using a 3000 Da molecular weight cutoff. Freeze-dried or heat-dried to obtain a yellow-white powder. 0.1-2 g of CTAB, 0.01-1 g of TEA, and 0.02-2 g of PCDs powder were added to 10-50 ml of water and refluxed for 1-2 hours at 20-75°C and a stirring speed of 80-300 rpm. A cyclohexane solution of TEOS (1-10 ml of TEOS and 5-20 ml of cyclohexane) was then added to the reaction system. The mixture was then refluxed for 20-30 hours at 60-80°C and a stirring speed of 80-300 rpm. After the reflux reaction is completed, the mixed solution containing CDs obtained by the reflux reaction is allowed to stand and cool to room temperature. After separation, the upper layer is removed to obtain a milky yellow-white substance in the lower layer. The lower layer is washed three times with deionized water and anhydrous ethanol to remove excess CDs and unreacted raw material small molecules. Finally, the obtained product is dispersed in deionized water to obtain water-soluble CDs@DMSN room temperature phosphorescent microsphere material.

[0087] Example 5: Preparation using phosphoric acid and polyvinyl alcohol as raw materials (preparation of mesoporous silicon by oil-water two-phase separation method, carbon dots containing hydroxyl and phosphoric acid groups)

[0088] 0.1-1g of phosphoric acid and 0.5-2ml of polyvinyl alcohol are added to 40-100ml of water and hydrothermally reacted at 200°C for 5-10 hours. After cooling to room temperature, the mixture is filtered and dialyzed using a 3000Da molecular weight cutoff. A yellow-white powder is obtained by freeze-drying or heat-drying. 0.1-2g of CTAB, 0.01-1g of TEA, and 0.02-2g of CDs powder are added to 10-50ml of water and refluxed for 1-2 hours at a temperature of 20-75°C and a stirring speed of 80-300rpm. A cyclohexane solution of TEOS (1-10ml of TEOS and 5-20ml of cyclohexane) is then added to the reaction system and refluxed for 20-30 hours at 60-80°C with a stirring speed of 80-300rpm. After the reflux reaction is completed, the mixed solution containing CDs obtained by the reflux reaction is allowed to stand and cool to room temperature. After separation, the upper layer is removed to obtain a milky yellow-white substance in the lower layer. The lower layer is washed three times with deionized water and anhydrous ethanol to remove excess CDs and unreacted raw material small molecules. Finally, the obtained product is dispersed in deionized water to obtain water-soluble CDs@DMSN room temperature phosphorescent microsphere material.

[0089] Example 6: Preparation using lysine and ethylenediamine as raw materials (preparation of mesoporous silicon by oil-water two-phase separation method, carbon dots containing amino and carboxyl groups)

[0090] 0.1-1g of lysine and 0.5-2ml of ethylenediamine are added to 40-100ml of water and hydrothermally reacted at 200°C for 5-10 hours. After cooling to room temperature, the mixture is filtered and dialyzed using a 3000Da molecular weight cutoff. Freeze-dried or heat-dried to obtain a yellow-white powder. 0.1-2g of CTAB, 0.01-1g of TEA, and 0.02-2g of CDs powder are added to 10-50ml of water and refluxed for 1-2 hours at a temperature of 20-75°C and a stirring speed of 80-300rpm. A cyclohexane solution of TEOS (1-10ml of TEOS and 5-20ml of cyclohexane) is then added to the reaction system and refluxed for 20-30 hours at 60-80°C with a stirring speed of 80-300rpm. After the reflux reaction is completed, the mixed solution containing CDs obtained by the reflux reaction is allowed to stand and cool to room temperature. After separation, the upper layer is removed to obtain a milky yellow-white substance in the lower layer. The lower layer is washed three times with deionized water and anhydrous ethanol to remove excess CDs and unreacted raw material small molecules. Finally, the obtained product is dispersed in deionized water to obtain water-soluble CDs@DMSN room temperature phosphorescent microsphere material.

[0091] Comparative Example 1

[0092] 1-4 ml of ethanolamine and 2-16 ml of phosphoric acid were added to 10-20 ml of water and microwaved at 700 W for 2-7 minutes. After cooling to room temperature, the solidified solid formed a dark brown gel. Dissolved in deionized water, the solution was neutralized to pH 7 with a weak base (Na2CO3), filtered, and dialyzed with a 1000 Da molecular weight cutoff. Freeze-drying or heat-drying yielded a yellow powder, representing solid phosphorescent carbon dots.

[0093] Comparative Example 2

[0094] 1-4 ml of ethanolamine and 2-16 ml of phosphoric acid were added to 10-20 ml of water and microwaved at 700 W for 2-7 minutes. After cooling to room temperature, the mixture solidified into a dark brown gel-like solid. After dissolution with deionized water and neutralization with a weak base (Na2CO3) to a pH of 7, the mixture was filtered through a membrane with a molecular weight cutoff of 1000 Da and then freeze-dried or heat-dried to obtain a yellow powder. 0.02-2 g of CDs powder was added to 10-50 ml of water. 4-8 ml of TEOS and 0.5-3 ml of ammonia were then added to the reaction system and refluxed for 4-8 hours at a temperature of 75-120°C and a stirring speed of 80-300 rpm. After reflux, the resulting CDs-containing solution was allowed to stand until room temperature and then washed three times with deionized water and anhydrous ethanol to remove excess CDs and unreacted starting small molecules, resulting in solid-state phosphorescent carbon dots.

[0095] Comparative Example 3

[0096] 10 mg of polythiophene (PT2) and 10 mg of diphenylene were dispersed in 15 ml of 0.5 mM aqueous NaOH solution. The mixture was transferred to an autoclave and heated at 180°C for 24 hours. After cooling to room temperature, the CDs powder was purified by filtration, centrifugation, dialysis, and lyophilization to collect. 0.02-2 g of CDs powder was added to 10-50 ml of water. Subsequently, 4-8 ml of TEOS and 0.513 ml of aqueous ammonia were added to the reaction system and refluxed for 4-8 hours. The reflux temperature was 75-120°C and the stirring speed was 80-300 rpm. After reflux, the resulting CDs-containing mixed solution was allowed to stand at room temperature and then washed three times with deionized water and anhydrous ethanol to remove excess CDs and unreacted starting small molecules, resulting in solid-state phosphorescent carbon dots.

[0097] The CDs in Comparative Examples 1-3 are solid-state phosphorescent carbon dots. Since phosphorescence is generated by the radiative transition between the lowest triplet state and the ground state, it is easily quenched by water and dissolved oxygen. Therefore, no phosphorescence is detected in the aqueous phase. Figure 9 This is the solid-state phosphorescence lifetime spectrum of the CDs powder in Comparative Example 3 of the present invention; the room-temperature phosphorescent microsphere material prepared in this application has excellent aqueous phase phosphorescence performance, which solves the problem that existing solid-state phosphorescent carbon dots cannot achieve phosphorescence emission in the aqueous phase.

[0098] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments using other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0099] It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical variations made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a water-soluble room temperature phosphorescent microsphere material, characterized in that include: An organic acid and an organic amine are subjected to a microwave reaction to obtain a phosphorescent carbon dot material; wherein the microwave reaction causes at least one or more functional groups of hydroxyl, carboxyl, and amino groups to be distributed on the surface of the phosphorescent carbon dot material; the organic acid is phosphoric acid; and the organic amine is ethanolamine; Also, a first mixed reaction system comprising hexadecyltrimethylammonium bromide, triethylamine and the phosphorescent carbon dot material is reacted, and then a silicon source is added and refluxed at 60°C to 80°C for 20 to 30 hours to obtain a water-soluble room temperature phosphorescent microsphere material; or, hexadecyltrimethylammonium bromide is reacted with triethylamine, and then the phosphorescent carbon dot material and a silicon source are added and the reaction is continued to obtain a water-soluble room temperature phosphorescent microsphere material.

2. The preparation method according to claim 1, wherein Specifically include: The organic acid, the organic amine and the solvent are mixed and subjected to microwave reaction, and then subjected to purification treatment to obtain a phosphorescent carbon dot material; Wherein, the solvent is selected from water; the molar ratio of the organic acid to the organic amine is 20:1 to 50:1; and the purification treatment is selected from dialysis and / or filtration.

3. The preparation method according to claim 1, wherein Specifically include: allowing a first mixed reaction system comprising hexadecyltrimethylammonium bromide, triethylamine, the phosphorescent carbon dot material, and water to react at room temperature for 1 to 3 hours to obtain a first intermediate product; Furthermore, a silicon source is added to the first intermediate product to carry out a reflux reaction, and then the obtained product is centrifuged and washed to prepare a water-soluble room temperature phosphorescent microsphere material.

4. The preparation method according to claim 1, characterized in that Specifically include: Stirring an aqueous solution containing hexadecyltrimethylammonium bromide and triethylamine at room temperature for 1 to 2 hours to obtain a template; Furthermore, phosphorescent carbon dot material and silicon source are added to the template and refluxed at 60° C. to 80° C. for 20 to 30 hours. The obtained product is then centrifuged and washed to obtain a water-soluble room temperature phosphorescent microsphere material.

5. The preparation method according to claim 1, wherein: The silicon source includes tetraethyl orthosilicate and an oil phase solvent, wherein the oil phase solvent is selected from any one of cyclohexane and n-hexane or a combination of the two; the concentration of tetraethyl orthosilicate in the silicon source is 0.5-2 mol / L; the dropwise addition rate of the silicon source is 0.1-0.5 ml / min; And / or, the usage ratio of the phosphorescent carbon dot material, hexadecyltrimethylammonium bromide, triethylamine and silicon source is 0.02-2 g: 0.1-2 g: 0.01-1 g: 1-10 ml.

6. A water-soluble room temperature phosphorescent microsphere material prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The water-soluble room temperature phosphorescent microsphere material comprises dendritic mesoporous silicon and phosphorescent carbon dot materials dispersed in the skeleton and pores of the dendritic mesoporous silicon by means of chemical bonds.

7. The water-soluble room temperature phosphorescent microsphere material according to claim 6, characterized in that: The mass ratio of the phosphorescent carbon dot material to the dendritic mesoporous silicon in the water-soluble room temperature phosphorescent microsphere material is 1:50 to 10:50; and / or, the particle size of the phosphorescent carbon dot material is less than 10 nm; and / or, the particle size of the dendritic mesoporous silicon is 50-300 nm; and / or, the pore diameter of the dendritic mesoporous silicon is 3-25 nm; And / or, the phosphorescent carbon dot material has a phosphorescent emission wavelength of 400-500 nm.

8. The water-soluble room temperature phosphorescent microsphere material according to claim 6, characterized in that: The phosphorescence emission wavelength of the water-soluble room temperature phosphorescent microsphere material is the same as the emission wavelength of the phosphorescent carbon dot material; And / or, the phosphorescence emission wavelength of the water-soluble room temperature phosphorescent microsphere material is in the range of 400-500 nm.

9. The water-soluble room temperature phosphorescent microsphere material according to claim 6, characterized in that: The solid state of the water-soluble room temperature phosphorescent microsphere material has bright phosphorescence at room temperature; And / or, the water-soluble room temperature phosphorescent microsphere material has phosphorescence in water phase or ethanol phase.

10. Use of the water-soluble room temperature phosphorescent microsphere material according to any one of claims 6 to 9 in non-diagnostic biomedical analysis, environmental monitoring and food safety analysis.

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