CN109536162B - Preparation method of simple carbon dots - Google Patents
Preparation method of simple carbon dots Download PDFInfo
- Publication number
- CN109536162B CN109536162B CN201811515618.6A CN201811515618A CN109536162B CN 109536162 B CN109536162 B CN 109536162B CN 201811515618 A CN201811515618 A CN 201811515618A CN 109536162 B CN109536162 B CN 109536162B
- Authority
- CN
- China
- Prior art keywords
- sulfuric acid
- concentrated sulfuric
- solution
- carbon
- carbon dots
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/65—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Nanotechnology (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Optics & Photonics (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Manufacturing & Machinery (AREA)
- Organic Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Biophysics (AREA)
- Inorganic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Pathology (AREA)
- Carbon And Carbon Compounds (AREA)
- Luminescent Compositions (AREA)
Abstract
The invention provides a preparation method of carbon dots, which comprises the following steps: providing a mixed system of the fused ring aromatic compound and concentrated sulfuric acid according to the mass-volume ratio of 50mg (1-5 mL) of the fused ring aromatic compound to the concentrated sulfuric acid; heating the mixed system of the condensed ring aromatic compound and concentrated sulfuric acid at the temperature of between 25 and 80 ℃, reacting for 1.5 to 10 minutes, and collecting reaction liquid; dissolving the reaction solution in deionized water to form a mixed solution, and adding an inorganic base to adjust the pH of the solution to be neutral; carrying out ultrafiltration treatment on the mixed solution by adopting a 3KD ultrafiltration tube, and collecting a product with the molecular weight more than or equal to 3 KD; and (3) carrying out ultrafiltration treatment on the product with the molecular weight of 3KD or more by adopting an ultrafiltration tube with 50KD to obtain carbon points with the molecular weight of 3KD-50 KD.
Description
Technical Field
The invention belongs to the technical field of nano materials, and particularly relates to a preparation method of simple carbon dots.
Background
The carbon dot is a dispersed spheroidal fluorescent carbon nanoparticle having a size of less than 10 nm. The first time in 2004 was discovered by the Scirvens project group. Since the discovery, the advantages of carbon dots such as low toxicity, good biocompatibility and excellent luminescence property attract the research interest of the majority of scientists. The current methods for preparing carbon dots are generally divided into two types: top-down and bottom-up. The method mainly comprises the following steps: arc discharge, laser ablation, electrochemical oxidation, combustion, templating, hydrothermal, thermal decomposition of organic matter, and the like. However, most of the methods need expensive instruments, or need high experimental skills, or have high temperature and high pressure, so that the method has great potential safety hazards and greatly limits the development of carbon spots.
Researchers have obtained graphitized carbon dots with a particle size of 1-4nm and a fluorescence quantum yield of 25% (y.liu, c. -y.liu and z. -y.zhang, Applied surface science,2012,263,481-485) by heating a concentrated sulfuric acid solution of ethylene glycol at 140 ℃. Further research by researchers has revealed that the fluorescence quantum yield can be further improved and can reach as high as 62.9% after the pyrolysis temperature is reduced to 80 ℃ (Y.Liu, C.Y.Liu and Z.Y.Zhang, Journal of materials Chemistry C,2013,1,4902 and 4907). The carbon dots are prepared by the method, steps such as pretreatment, precursor preparation and the like are not needed, and the problems of experiment difficulty, cost and the like are greatly reduced. However, the carbon dots prepared by this method have poor uniformity of particle size, and a large amount of sulfuric acid remains when the carbon dots are prepared by this method, which affects the study of the carbon dots on non-acid-resistant and non-corrosion-resistant objects.
Disclosure of Invention
The invention aims to provide a simple carbon dot preparation method, which adopts an ultrafiltration post-treatment technology to prepare carbon dots, reduces the threshold of carbon dot research, and can solve the problem of poor uniformity of the particle size of the carbon dots prepared by the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a preparation method of carbon dots, which comprises the following steps:
providing a mixed system of the fused ring aromatic compound and concentrated sulfuric acid according to the mass-volume ratio of the fused ring aromatic compound to the concentrated sulfuric acid being more than or equal to 50mg:1 mL;
heating the mixed system of the condensed ring aromatic compound and concentrated sulfuric acid at the temperature of between 25 and 80 ℃, reacting for 1.5 to 10 minutes, and collecting reaction liquid;
dissolving the reaction solution in deionized water to form a mixed solution, and adding an inorganic base to adjust the pH of the solution to be neutral;
carrying out ultrafiltration treatment on the mixed solution by adopting a 3KD ultrafiltration tube, and collecting a product with the molecular weight more than or equal to 3 KD; and (3) carrying out ultrafiltration treatment on the product with the molecular weight of 3KD or more by adopting an ultrafiltration tube with 50KD to obtain carbon points with the molecular weight of 3KD-50 KD.
In a second aspect, the present invention provides a carbon dot prepared by the above method.
The third aspect of the invention provides the application of the carbon dots prepared by the method in the technical field of cell imaging.
According to the preparation method of the carbon dots, the polycyclic aromatic hydrocarbon compound is used as a carbon source, is mixed with concentrated sulfuric acid, and is heated at the temperature of 25-80 ℃ to prepare the carbon dots; further, after the obtained reaction solution is neutralized by adding alkali, ultrafiltration treatment is respectively carried out by adopting ultrafiltration tubes with 3KD and 50 KD. The method for preparing the carbon dots has the following advantages: firstly, the carbon dots prepared by the method not only have high luminous efficiency, but also have good particle size uniformity. And secondly, the carbon dots prepared by the method can be completely dissolved in water, have stable fluorescence performance under physiological conditions, have excellent performance, do not have acid-base corrosion phenomenon, and have good application prospect in the technical field of cell imaging. Thirdly, the yield of carbon dots prepared by the method is high and can reach more than 50%. In addition, the method for preparing the carbon dots has mild conditions, can prepare and obtain the carbon dots with high yield under the condition of being lower than 50 ℃, does not need expensive instruments, and has the advantages of simple reaction operation (one-step reaction) and green and mild conditions.
The carbon dots provided by the invention are prepared by the method, so that the carbon dots have the advantages of good particle size uniformity, stable fluorescence performance and no acid-base corrosion phenomenon, and have good application prospects in the technical field of cell imaging.
The carbon dots provided by the invention can be completely dissolved in water and have stable fluorescence performance under physiological conditions, so that the carbon dots can be used in the technical field of cell imaging and can fill up the defects of pure organic fluorescent probes.
Drawings
FIG. 1 is a fluorescence spectrum of carbon dots prepared under different temperature conditions according to an embodiment of the present invention;
FIG. 2 is a graph of excitation spectra of carbon dots provided by an embodiment of the present invention;
FIG. 3 is a graph showing the change of fluorescence intensity of carbon dots in different concentrations of NaCl according to an embodiment of the present invention;
FIG. 4 is a graph showing the change of fluorescence intensity of carbon dots under 365nm excitation wavelength irradiation according to an embodiment of the present invention;
FIG. 5 is a graph showing the change of fluorescence intensity of carbon dots under different pH conditions according to the present invention;
FIG. 6a is a photograph of a bright field fluorescence image of carbon dot incubated cells according to an embodiment of the present invention;
FIG. 6b is a dark field fluorescence image of carbon dot incubated cells provided by an embodiment of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
The first aspect of the embodiments of the present invention provides a method for preparing carbon dots, including the following steps:
s01, providing a mixed system of the fused ring aromatic compound and concentrated sulfuric acid according to the mass-to-volume ratio of the fused ring aromatic compound to the concentrated sulfuric acid being greater than or equal to 50mg:1 mL;
s02, heating the mixed system of the condensed ring aromatic compound and concentrated sulfuric acid at the temperature of 25-80 ℃, reacting for 1.5 h-10 min, and collecting reaction liquid;
s03, dissolving the reaction solution in deionized water to form a mixed solution, and adding an inorganic base to adjust the pH of the solution to be neutral;
s04, performing ultrafiltration treatment on the mixed solution by adopting a 3KD ultrafiltration tube, and collecting a product with the molecular weight being more than or equal to 3 KD; and (3) carrying out ultrafiltration treatment on the product with the molecular weight of 3KD or more by adopting an ultrafiltration tube with 50KD to obtain carbon points with the molecular weight of 3KD-50 KD.
According to the preparation method of the carbon dots, provided by the embodiment of the invention, the polycyclic aromatic hydrocarbon compound is used as a carbon source, is mixed with concentrated sulfuric acid, and is heated at the temperature of 25-80 ℃ to prepare the carbon dots; further, after the obtained reaction solution is neutralized by adding alkali, ultrafiltration treatment is respectively carried out by adopting ultrafiltration tubes with 3KD and 50 KD. The method for preparing the carbon dots has the following advantages: firstly, the carbon dots prepared by the method not only have high luminous efficiency, but also have good particle size uniformity. And secondly, the carbon dots prepared by the method can be completely dissolved in water, have stable fluorescence performance under physiological conditions, have excellent performance, do not have acid-base corrosion phenomenon, and have good application prospect in the technical field of cell imaging. Thirdly, the yield of carbon dots prepared by the method is high and can reach more than 50%. In addition, the method for preparing the carbon dots has mild conditions, can prepare and obtain the carbon dots with high yield under the condition of being lower than 50 ℃, does not need expensive instruments, and has the advantages of simple reaction operation (one-step reaction) and green and mild conditions.
Specifically, in step S01, the fused ring aromatic hydrocarbon compound is used as a carbon source, and the carbon dots obtained by heating with concentrated sulfuric acid have an advantage of high luminous efficiency. In the embodiment of the present invention, it is particularly preferable that the condensed ring aromatic hydrocarbon compound is 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene. Of course, it is understood that the carbon dots prepared by using other fused ring aromatic hydrocarbon compounds as carbon sources also have better luminous efficiency, but among them, the carbon dots prepared by using 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene as a carbon source have the highest luminous efficiency.
In the embodiment of the present invention, the concentrated sulfuric acid used for carbonizing the fused ring aromatic compound is concentrated sulfuric acid with a mass percentage higher than 98%, and particularly preferably, concentrated sulfuric acid with a mass percentage of 98.3% is selected. The concentrated sulfuric acid with the mass percentage of 98.3% not only has better carbonization effect, but also is relatively easy to obtain.
In the embodiment of the invention, the condensed ring aromatic compound and concentrated sulfuric acid are mixed according to the mass-to-volume ratio of 50mg:1mL or more to form a mixed system of the condensed ring aromatic compound and the concentrated sulfuric acid. If the mass volume ratio of the condensed ring aromatic compound to concentrated sulfuric acid is less than 50mg:1mL, the concentration of the concentrated sulfuric acid is too low during the reaction, so that the condensed ring aromatic compound is not carbonized to form a carbon point.
In some preferred embodiments, in the step of providing the mixed system of the fused ring aromatic compound and the concentrated sulfuric acid, the fused ring aromatic compound is added to the concentrated sulfuric acid in a mass-to-volume ratio of the fused ring aromatic compound to the concentrated sulfuric acid of 50mg (1-3) mL. In a specific example, when the fused ring aromatic compound is 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene, 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene is added to concentrated sulfuric acid in a mass-to-volume ratio of the 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene to the concentrated sulfuric acid of 50mg:1.5mL, to obtain a mixed system of the fused ring aromatic compound and the concentrated sulfuric acid.
In step S02, the mixed system of the fused ring aromatic compound and concentrated sulfuric acid is heated, and the fused ring aromatic compound is carbonized to a carbon point by the concentrated sulfuric acid. Specifically, the heating temperature for carbonizing the condensed ring aromatic hydrocarbon compound into the carbon point by using concentrated sulfuric acid is 25-80 ℃, the conversion of the condensed ring aromatic hydrocarbon compound into the carbon point can be realized under the temperature condition, and the obtained carbon point has good particle size uniformity, fluorescence stability and water solubility. The reaction progress is monitored by monitoring the solubility of the reaction solution in water in the reaction process, and the reaction solution can be completely dissolved in water to represent complete reaction. In the embodiment of the invention, the time of the heating treatment is 1.5 h-10 min, and the specific carbonization time is changed according to the carbonization temperature. Generally, the higher the carbonization temperature, the relatively shorter the carbonization time; the lower the carbonization temperature, the longer the carbonization time. It is to be noted that, at different temperatures, the yield of carbon points varies, and at temperatures lower than 38 ℃, the fused ring aromatic compound is difficult to be completely carbonized; under the condition that the temperature is 38-80 ℃, the condensed ring aromatic hydrocarbon compound can be completely carbonized by the concentrated sulfuric acid, and the carbon points with higher yield are obtained. Therefore, in a preferred embodiment, the step of subjecting the mixed system of the condensed ring aromatic hydrocarbon compound and concentrated sulfuric acid to heat treatment is performed at a temperature of 38 to 80 ℃.
In the method for preparing the carbon dots, although the fused ring aromatic compound can be carbonized under the heating condition of 80 ℃ to prepare the carbon dots, the high yield and the high performance (particle size uniformity, fluorescence stability and water solubility) can be prepared under the heating condition of relatively low temperature, such as 38-50 ℃, compared with the existing high-temperature condition, the mild reaction condition is provided, the reaction difficulty is reduced, and the potential safety hazard can be effectively avoided.
After the reaction, the reaction solution was collected and further treated.
In step S03, the reaction solution is dissolved in deionized water, and the prepared carbon dots are dissolved to form a mixed solution. In a preferred embodiment, in the step of dissolving the reaction solution in deionized water to form a mixed solution, the reaction solution is added into the deionized water according to the volume ratio of concentrated sulfuric acid to deionized water (1-5): 50, which is beneficial to fully dissolving the obtained carbon dots in water, and further can be collected by subsequent ultrafiltration.
Further, the inorganic base is added to the mixed solution to adjust the pH of the solution to be neutral, and the concentrated sulfuric acid in the solution and attached to the carbon dots is sufficiently removed and simultaneously converted into water-soluble sulfate or sulfate precipitate, so that the influence of the residual sulfuric acid on the performance of the carbon dots can be avoided, and the influence of the residual sulfuric acid on the application of the carbon dots, particularly the application of the carbon dots in non-acid-resistant and non-corrosion-resistant objects, can be further avoided.
In the embodiment of the invention, inorganic base is adopted to adjust the pH of the solution, so that the reaction safety is better, only salt impurities are introduced, and the reaction with carbon dots is avoided, so that the performance of the carbon dots is not influenced. The inorganic base used for adjusting the pH of the solution may be a conventional inorganic base, and preferably at least one of sodium hydroxide, potassium hydroxide, and barium hydroxide is used. The inorganic bases have good pH adjusting effect, and the generated salt is easy to remove, thereby being beneficial to obtaining high-purity carbon dots.
In step S04, in the embodiment of the present invention, the carbon dots in the mixed solution are purified by using an ultrafiltration tube. On one hand, the mixed solution is ultrafiltered by adopting a 3KD ultrafiltration tube, small molecules such as salt, solvent and the like are removed by centrifugation, and products with the molecular weight more than or equal to 3KD are collected; meanwhile, the product with the molecular weight more than or equal to 3KD is ultrafiltered by adopting a 50KD ultrafiltration tube, and large particle impurities without luminescence property are removed by centrifugation, so that carbon dots with the molecular weight of 3KD-50KD are obtained.
As a most preferred embodiment, the method for preparing the carbon dots comprises the following steps:
providing a mixed system of 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene and concentrated sulfuric acid according to the mass-volume ratio of 50mg:1.5mL of the 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene to the concentrated sulfuric acid, wherein the mass percentage of the sulfuric acid is 98.3%;
heating the mixed system of the 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene and concentrated sulfuric acid at 38 ℃, reacting for 1.5h, and collecting reaction liquid;
according to the volume ratio of concentrated sulfuric acid to deionized water of 3: 50, dissolving the reaction solution in deionized water to form a mixed solution, and adding sodium hydroxide to adjust the pH of the solution to be neutral;
carrying out ultrafiltration treatment on the mixed solution by adopting a 3KD ultrafiltration tube, and collecting a product with the molecular weight more than or equal to 3 KD; and (3) carrying out ultrafiltration treatment on the product with the molecular weight of 3KD or more by adopting an ultrafiltration tube with 50KD to obtain carbon points with the molecular weight of 3KD-50 KD.
The optimal method has mild preparation reaction conditions, and the obtained carbon dots have good particle size uniformity and fluorescence property stability, can be completely dissolved in water, have good fluorescence property and biocompatibility on iron ions, and can monitor the content of the iron ions in living cells under physiological conditions.
In a second aspect of the embodiments of the present invention, there is provided a carbon dot prepared by the above method.
The carbon dots provided by the embodiment of the invention are prepared by the method, so that the carbon dots have the advantages of good particle size uniformity, stable fluorescence performance and no acid-base corrosion phenomenon, and have good application prospects in the technical field of cell imaging.
The third aspect of the embodiments of the present invention provides an application of the carbon dots prepared by the above method in the technical field of cell imaging.
The carbon dots provided by the embodiment of the invention can be completely dissolved in water and have stable fluorescence performance under physiological conditions, so that the carbon dots can be applied to the technical field of cell imaging and can fill up the defects of pure organic fluorescent probes.
The following description will be given with reference to specific examples.
Example 1
A preparation method of carbon dots comprises the following steps:
50mg of 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene was accurately weighed, and added to 1.5mL of concentrated sulfuric acid to react at room temperature at 25 ℃ (the reaction progress was monitored by monitoring the solubility of the reaction solution in water during the reaction, and the reaction solution was completely dissolved in water, which means the reaction was complete). We found that, under these conditions, when a drop of the reaction mixture was dropped into 10mL of the aqueous solution after 20 hours of the reaction, some of the reaction mixture was soluble in water, but some insoluble matter remained, i.e., the reaction was not complete, the solution showed white fluorescence, and the reaction time was not significantly changed.
And slowly dripping all the reaction solution into 25mL of secondary water, adding NaOH, adjusting the solution to be neutral, removing small molecules such as salt, solvent and the like by ultrafiltration and centrifugation of a 3KD ultrafiltration tube, then removing large-particle impurities by ultrafiltration and centrifugation of a 50KD ultrafiltration tube, and reserving carbon dot products of 3KD-50 KD.
Example 2
A preparation method of carbon dots comprises the following steps:
50mg of 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene was accurately weighed, added to 1.5mL of concentrated sulfuric acid, and reacted at 38 ℃ (the reaction progress was monitored by monitoring the solubility of the reaction solution in water during the reaction, and the reaction solution was completely dissolved in water, which means the reaction was complete). We found that, under these conditions, after about 1.5 hours of reaction, one drop of the reaction solution was dropped into 10mL of the aqueous solution, the reactants were all dissolved in water, and the solution was clear and transparent, i.e., the reaction was complete, and the solution showed strong white fluorescence.
And (3) slowly dripping all the reaction solution into 25mL of secondary water, adding KOH, adjusting the solution to be neutral, removing small molecules such as salt and solvent by ultrafiltration and centrifugation with an ultrafiltration tube of 3KD, removing large-particle impurities by ultrafiltration and centrifugation with an ultrafiltration tube of 50KD, and reserving carbon dot products of 3KD-50 KD.
Example 3
A preparation method of carbon dots comprises the following steps:
50mg of 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene was accurately weighed, added to 1.5mL of concentrated sulfuric acid, and reacted at 50 ℃ (the reaction progress was monitored by monitoring the solubility of the reaction solution in water during the reaction, and the reaction solution was completely dissolved in water, which means the reaction was complete). We found that, under these conditions, after about 1.2 hours of reaction, one drop of the reaction solution was dropped into 10mL of the aqueous solution, the reactants were all dissolved in water, and the solution was clear and transparent, i.e., the reaction was complete, and the solution showed strong white fluorescence.
And slowly dripping all the reaction solution into 25mL of secondary water, adding NaOH, adjusting the solution to be neutral, removing small molecules such as salt, solvent and the like by ultrafiltration and centrifugation of a 3KD ultrafiltration tube, then removing large-particle impurities by ultrafiltration and centrifugation of a 50KD ultrafiltration tube, and reserving a part of target carbon dot products of 3KD-50 KD.
Example 4
A preparation method of carbon dots comprises the following steps:
50mg of 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene was accurately weighed, added to 1.5mL of concentrated sulfuric acid, and reacted at 65 ℃ (the reaction progress was monitored by monitoring the solubility of the reaction solution in water during the reaction, and the reaction solution was completely dissolved in water, which means the reaction was complete). We found that, under these conditions, after about 1.0 hour of reaction, one drop of the reaction solution was dropped into 10mL of the aqueous solution, the reactants were all dissolved in water, and the solution was clear and transparent, i.e., the reaction was complete, and the solution showed strong white fluorescence.
And slowly dripping all the reaction solution into 25mL of secondary water, adding NaOH, adjusting the solution to be neutral, removing small molecules such as salt, solvent and the like by ultrafiltration and centrifugation of a 3KD ultrafiltration tube, then removing large-particle impurities by ultrafiltration and centrifugation of a 50KD ultrafiltration tube, and reserving carbon dot products of 3KD-50 KD.
Example 5
A preparation method of carbon dots comprises the following steps:
50mg of 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene was accurately weighed, added to 1.5mL of concentrated sulfuric acid, and reacted at a temperature of 80 ℃ (the reaction progress was monitored by monitoring the solubility of the reaction solution in water during the reaction, and the reaction solution was completely dissolved in water, which means that the reaction was complete). We found that, under these conditions, after about 10 minutes of reaction, one drop of the reaction solution was dropped into 10mL of the aqueous solution, the reactants were all dissolved in water, and the solution was clear and transparent, i.e., the reaction was complete, and the solution showed strong white fluorescence.
And slowly dripping all the reaction solution into 25mL of secondary water, adding NaOH, adjusting the solution to be neutral, removing small molecules such as salt, solvent and the like by ultrafiltration and centrifugation of a 3KD ultrafiltration tube, then removing large-particle impurities by ultrafiltration and centrifugation of a 50KD ultrafiltration tube, and reserving carbon dot products of 3KD-50 KD.
The carbon dots prepared in examples 1 to 5 were subjected to fluorescence property test, and fluorescence spectra of the carbon dots prepared under different temperature conditions are shown in FIG. 1. As can be seen from FIG. 1, the fluorescence emission peak of the prepared carbon dots has the same peak position and peak shape under different temperature adjustments, and has the maximum emission peak at 514nm, but the fluorescence intensity has a certain difference. Generally, the carbon dots have quantum size effect, i.e. different particle size, and the emission spectrum is different. Therefore, the carbon dots prepared by the embodiment of the invention have better particle size uniformity.
The carbon dots prepared by the embodiment of the invention are prepared into a carbon dot solution with the concentration of 5ppm by secondary water, and are excited by different excitation wavelengths, and the excitation spectrum is shown in figure 2. As shown in fig. 2, the maximum fluorescence emission peak of the carbon dot, which does not change with the change of the excitation wavelength, illustrates that the carbon dots prepared by the embodiment of the present invention have uniform size and thus relatively independent fluorescence emission peaks.
The carbon dots prepared in the example were prepared into a carbon dot solution with a concentration of 5ppm using secondary water, a sodium chloride solution was gradually added to the carbon dot solution, and when the concentration of sodium chloride was 0-100mM, the fluorescence intensity of the carbon dots decreased, and then the fluorescence intensity of the carbon dots tended to stabilize and hardly changed when the concentration of sodium chloride was continued from 100-500mM, as shown in FIG. 3. This demonstrates that the carbon dots prepared in this example have strong ion tolerance.
The carbon dots prepared in the example were prepared into a carbon dot solution with a concentration of 5ppm by using secondary water, and the carbon dot solution was irradiated at an excitation wavelength of 365nm for 7 hours, and as shown in fig. 4, it can be seen that the change of fluorescence intensity after long-time irradiation is almost negligible, indicating that the carbon dots prepared in the example have high stability.
The fluorescence intensity of the carbon dots prepared in the test examples was measured in a pH range (pH 3 to pH 9), and the results are shown in FIG. 5. As can be seen, the carbon dots prepared in this example are also relatively stable in the range of pH 3 to pH 9, i.e., the carbon dots prepared in the examples of the present invention have good stability.
The carbon dots prepared in the example were incubated with the cells in a pure water solution under physiological conditions, and observed under a fluorescence inverted microscope, and the image of the bright field of the cells is shown in FIG. 6a, and the image of the dark field of the cells is shown in FIG. 6b, and the image of the green fluorescence of the cells in the green channel is shown in FIG. 6 b. From the figure, it was found that the cells have strong fluorescence, indicating that the cells have good absorption of carbon spots. It is worth mentioning that, at present, the organic fluorescent probe has excellent fluorescence performance, but because the organic fluorescent probe is often difficult to be dissolved in water, the research on imaging application of the organic fluorescent probe in aspects of cell living bodies and the like is greatly restricted, which is a natural disadvantage of organic compounds in biological application and is difficult to overcome. The carbon dots prepared by the embodiment of the invention can be completely dissolved in water, and have stable fluorescence performance under physiological conditions, thereby just filling the defects of pure organic fluorescent probes.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (8)
1. A preparation method of carbon dots is characterized by comprising the following steps:
providing a mixed system of a condensed ring aromatic compound and concentrated sulfuric acid according to the mass-volume ratio of 50mg (1-3) mL, wherein the condensed ring aromatic compound is 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene;
heating the mixed system of the condensed ring aromatic compound and concentrated sulfuric acid at the temperature of between 25 and 80 ℃, reacting for 1.5 to 10 minutes, and collecting reaction liquid;
dissolving the reaction solution in deionized water to form a mixed solution, and adding an inorganic base to adjust the pH of the solution to be neutral;
carrying out ultrafiltration treatment on the mixed solution by adopting a 3KD ultrafiltration tube, and collecting a product with the molecular weight more than or equal to 3 KD; and (3) carrying out ultrafiltration treatment on the product with the molecular weight of 3KD or more by adopting an ultrafiltration tube with 50KD to obtain carbon points with the molecular weight of 3KD-50 KD.
2. The method for producing a carbon dot according to claim 1, wherein the step of subjecting the mixed system of the condensed ring aromatic compound and concentrated sulfuric acid to heat treatment is performed at a temperature of 38 ℃ to 80 ℃.
3. The method for producing a carbon dot according to claim 1 or 2, wherein the inorganic base is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, and barium hydroxide.
4. The method for preparing a carbon dot according to claim 1 or 2, wherein in the step of dissolving the reaction solution in deionized water to form a mixed solution, the reaction solution is added to the deionized water in a volume ratio of concentrated sulfuric acid to deionized water of (1-5): 50.
5. The method for producing a carbon dot according to claim 1 or 2, wherein the concentrated sulfuric acid is 98.3% by mass of sulfuric acid.
6. The method for producing a carbon dot according to claim 1, comprising the steps of:
providing a mixed system of 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene and concentrated sulfuric acid according to the mass-volume ratio of 50mg:1.5mL of the 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene to the concentrated sulfuric acid, wherein the mass percentage of the sulfuric acid is 98.3%;
heating the mixed system of the 9- ((4- (tert-butyl) -2, 6-dimethylphenoxy) methyl) anthracene and concentrated sulfuric acid at 38 ℃, reacting for 1.5h, and collecting reaction liquid;
according to the volume ratio of concentrated sulfuric acid to deionized water of 3: 50, dissolving the reaction solution in deionized water to form a mixed solution, and adding sodium hydroxide to adjust the pH of the solution to be neutral;
carrying out ultrafiltration treatment on the mixed solution by adopting a 3KD ultrafiltration tube, and collecting a product with the molecular weight more than or equal to 3 KD; and (3) carrying out ultrafiltration treatment on the product with the molecular weight of 3KD or more by adopting an ultrafiltration tube with 50KD to obtain carbon points with the molecular weight of 3KD-50 KD.
7. A carbon dot produced by the method according to any one of claims 1 to 6.
8. Use of the carbon dots prepared according to any one of claims 1 to 6 in the field of cellular imaging technology.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811515618.6A CN109536162B (en) | 2018-12-12 | 2018-12-12 | Preparation method of simple carbon dots |
| PCT/CN2019/124310 WO2020119678A1 (en) | 2018-12-12 | 2019-12-10 | Carbon dot simple preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811515618.6A CN109536162B (en) | 2018-12-12 | 2018-12-12 | Preparation method of simple carbon dots |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109536162A CN109536162A (en) | 2019-03-29 |
| CN109536162B true CN109536162B (en) | 2020-05-22 |
Family
ID=65854366
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811515618.6A Active CN109536162B (en) | 2018-12-12 | 2018-12-12 | Preparation method of simple carbon dots |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN109536162B (en) |
| WO (1) | WO2020119678A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110724528B (en) * | 2019-11-07 | 2020-08-11 | 东北林业大学 | Rosin-based carbon dot material and preparation method and application thereof |
| CN116751586B (en) * | 2023-06-16 | 2024-03-12 | 山西大学 | Nitrogen-doped red fluorescent carbon dot and preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102897745A (en) * | 2012-08-06 | 2013-01-30 | 中国科学院理化技术研究所 | Method for preparing carbon quantum dots by using conjugated polymer and application thereof |
| CN103160279A (en) * | 2011-12-12 | 2013-06-19 | 中国科学院大连化学物理研究所 | Functional carbon dots, and preparation and application thereof |
| CN104087296A (en) * | 2014-07-08 | 2014-10-08 | 合肥工业大学 | Method for preparing fluorescent carbon quantum dots by laser irradiation |
| CN104843664A (en) * | 2015-03-04 | 2015-08-19 | 东华大学 | Method for preparing carbon nanodots based on chemical cutting |
| CN108502866A (en) * | 2017-12-21 | 2018-09-07 | 中国石油大学(北京) | A kind of carbon quantum dot and preparation method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10086334B2 (en) * | 2013-05-02 | 2018-10-02 | William Marsh Rice University | Bandgap engineering of carbon quantum dots |
| KR20170093826A (en) * | 2014-11-06 | 2017-08-16 | 윌리엄 마쉬 라이스 유니버시티 | Methods of making graphene quantum dots from various carbon sources |
| CN104743545B (en) * | 2015-03-11 | 2017-06-13 | 中国科学院青岛生物能源与过程研究所 | A kind of application of asphalt base carbon quantum dot prepared by the preparation method and the method for asphalt base carbon quantum dot |
| CN106315540A (en) * | 2015-06-18 | 2017-01-11 | 北京化工大学 | Method for preparing graphene quantum dot from asphalt |
| CN105523543A (en) * | 2015-12-21 | 2016-04-27 | 哈尔滨工业大学 | Method for preparing graphene quantum dots with grading increase |
| CN105860968B (en) * | 2016-04-29 | 2018-05-08 | 中国科学院理化技术研究所 | Single-layer single crystal graphene quantum dot and preparation method thereof |
| CN105836739A (en) * | 2016-05-12 | 2016-08-10 | 安徽大学 | Preparation method of multi-element doped graphene quantum dots |
-
2018
- 2018-12-12 CN CN201811515618.6A patent/CN109536162B/en active Active
-
2019
- 2019-12-10 WO PCT/CN2019/124310 patent/WO2020119678A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103160279A (en) * | 2011-12-12 | 2013-06-19 | 中国科学院大连化学物理研究所 | Functional carbon dots, and preparation and application thereof |
| CN102897745A (en) * | 2012-08-06 | 2013-01-30 | 中国科学院理化技术研究所 | Method for preparing carbon quantum dots by using conjugated polymer and application thereof |
| CN104087296A (en) * | 2014-07-08 | 2014-10-08 | 合肥工业大学 | Method for preparing fluorescent carbon quantum dots by laser irradiation |
| CN104843664A (en) * | 2015-03-04 | 2015-08-19 | 东华大学 | Method for preparing carbon nanodots based on chemical cutting |
| CN108502866A (en) * | 2017-12-21 | 2018-09-07 | 中国石油大学(北京) | A kind of carbon quantum dot and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| Simple Aqueous Solution Route to Luminescent Carbogenic Dots from Carbohydrates;Hui Peng等;《Chem.Mater.》;20090511;第5563-5565页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109536162A (en) | 2019-03-29 |
| WO2020119678A1 (en) | 2020-06-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107934936B (en) | Rapid preparation method of carbon quantum dots | |
| CN107418567B (en) | Biomass-based carbon quantum dot and preparation method thereof | |
| Deng et al. | N-doped carbon quantum dots as fluorescent probes for highly selective and sensitive detection of Fe3+ ions | |
| Wei et al. | Simple one-step synthesis of water-soluble fluorescent carbon dots derived from paper ash | |
| Liu et al. | Green synthesis of fluorescent carbon dots from carrot juice for in vitro cellular imaging | |
| Shen et al. | The production of pH-sensitive photoluminescent carbon nanoparticles by the carbonization of polyethylenimine and their use for bioimaging | |
| Kundu et al. | Facile approach to synthesize highly fluorescent multicolor emissive carbon dots via surface functionalization for cellular imaging | |
| CN108410457B (en) | Multifunctional fluorescent carbon quantum dot and preparation method and application thereof | |
| Zheng et al. | One pot selective synthesis of water and organic soluble carbon dots with green fluorescence emission | |
| CN103342347A (en) | Preparation method of carbon quantum dots with high fluorescence property | |
| Zhang et al. | Self-carbonization synthesis of highly-bright red/near-infrared carbon dots by solvent-free method | |
| CN109536162B (en) | Preparation method of simple carbon dots | |
| CN104909349A (en) | Nitrogen-doped fluorescent carbon dot preparation method | |
| Chen et al. | Pseudo-multicolor carbon dots emission and the dilution-induced reversible fluorescence shift | |
| CN106829920A (en) | A kind of green fluorescence carbon quantum dot material and preparation method thereof | |
| CN105368449A (en) | Nitrogen-doped multi-color fluorescent carbon dot and preparation method and application thereof | |
| CN105733573A (en) | Electrolytic and nitrogen-doping one-step method for preparing petroleum coke-based carbon quantum dots | |
| CN111573653A (en) | Nitrogen-sulfur self-doped fluorescent carbon quantum dot and preparation method and application thereof | |
| CN111518552B (en) | Preparation of fluorine-containing graphene quantum dots and application of fluorine-containing graphene quantum dots as photodynamic therapy photosensitizer | |
| Deeney et al. | Templated microwave synthesis of luminescent carbon nanofibers | |
| CN110041923B (en) | Preparation method and application of fluorescent carbon quantum dots Phe-CDs | |
| CN105567231A (en) | Method for compounding S-N co-doped fluorescent carbon dots through microwave heating | |
| CN109455692A (en) | A kind of chirality carbon quantum dot and preparation method thereof | |
| CN103771391A (en) | Preparation method of water-soluble carbon nanoparticles having fluorescent properties | |
| CN113025314A (en) | Simple method for rapidly preparing sulfur quantum dots |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |