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CN-121990559-A - Fluorescent carbon dot material and preparation method and application thereof

CN121990559ACN 121990559 ACN121990559 ACN 121990559ACN-121990559-A

Abstract

The invention provides a carbon dot material capable of emitting red fluorescence with quantum efficiency exceeding 90%, and a preparation method and application thereof. The preparation method of the fluorescent carbon dot material comprises the steps of dissolving 8-hydroxy julolidine-9-formaldehyde and organic carboxylic acid in water according to a proportion to prepare a mixture solution, carrying out hydrothermal reaction treatment on the mixture solution in a sealed environment, and then carrying out purification treatment. According to the preparation method of the fluorescent carbon dot material, the fluorescent carbon dot material is prepared and generated by adopting a hydrothermal method, so that the prepared fluorescent carbon dot material has very high quantum efficiency, low cost, low toxicity, stable particle size and stable fluorescence performance.

Inventors

  • YE SHUAI
  • XIAO YANG
  • SONG JUN
  • CHEN DANNI

Assignees

  • 深圳大学

Dates

Publication Date
20260508
Application Date
20260108

Claims (18)

  1. 1. A method for preparing a red high quantum efficiency fluorescent carbon dot material, comprising the steps of: (1) Dissolving a julolidine derivative containing hydroxyl and/or aldehyde groups and an organic acid containing one or more carboxyl groups or a salt thereof in an acidic reaction medium; (2) Placing the obtained solution in a closed container for hydrothermal or solvothermal reaction, wherein the reaction temperature is 120-220 ℃ and the reaction time is 2-24 hours; (3) Filtering the reaction solution and dialyzing the reaction solution with molecular weight cut-off of 300-1000Da to obtain the red fluorescent carbon dot material.
  2. 2. The method of claim 1, wherein the aromatic compound is selected from at least one of 8-hydroxyjulolidine-9-formaldehyde, 9-hydroxyjulolidine-8-formaldehyde, 8-hydroxyjulolidine-10-formaldehyde, or derivatives thereof.
  3. 3. The method of claim 1, wherein the organic acid is selected from the group consisting of citric acid, oxalic acid, tartaric acid, malic acid, succinic acid, glutaric acid, maleic acid, terephthalic acid, sulfanilic acid, or any combination thereof.
  4. 4. The method of claim 1, wherein the acidic reaction medium has a pH of 0.5-4 provided by hydrochloric acid, sulfuric acid, nitric acid, or a combination thereof.
  5. 5. The method of claim 1, wherein the solvent is water, ethanol, methanol, or a mixed system of water and a polar solvent.
  6. 6. The method of claim 1, wherein the filtration employs a 0.22 μm microporous filter membrane.
  7. 7. A red fluorescent carbon dot material is characterized in that: (1) The grain diameter is 1-10nm; (2) Contains C, O and/or N elements; (3) The surface contains at least one functional group of hydroxyl, carboxyl, ether bond, amide bond or imine bond; (4) Has excitation absorption peak in 540-620nm range and fluorescence emission peak in 580-650nm range; (5) The fluorescence quantum efficiency in dimethyl sulfoxide is more than or equal to 80 percent, preferably more than or equal to 90 percent; (6) A method according to any one of claims 1-6.
  8. 8. The fluorescent carbon dot material of claim 7, having a particle size of 2 to 6nm.
  9. 9. The fluorescent carbon dot material of claim 7, wherein the fluorescence emission peak at 370nm excitation is located at 590-610nm.
  10. 10. The fluorescent carbon dot material of claim 7, having a zeta potential in the range of +5mV to +45mV.
  11. 11. The fluorescent carbon dot material of claim 7, wherein the cell viability is not less than 90% in the concentration range of 0-400 μg/mL.
  12. 12. The fluorescent carbon dot material of claim 7, wherein stable red fluorescence intensity is maintained in a pH range of 3-12.
  13. 13. Use of red fluorescent carbon dot material in preparing mitochondrion targeting fluorescent imaging probe.
  14. 14. The use of claim 13, wherein the fluorescent carbon dot material is used for intracellular imaging, subcellular organelle labeling, bioluminescence probe, or living cell imaging.
  15. 15. The use according to claim 13, wherein the fluorescent carbon dot material is the material of any one of claims 7-12.
  16. 16. The use according to claim 13, wherein the fluorescent carbon dots have high photostability, low photobleaching and good biocompatibility.
  17. 17. The application of red fluorescent carbon dot material in preparing red luminous anti-fake ink.
  18. 18. The use according to claim 17, wherein the fluorescent carbon dots are used for a photo luminescent material.

Description

Fluorescent carbon dot material and preparation method and application thereof Technical Field The invention belongs to the technical field of chemical power supplies, and particularly relates to a fluorescent carbon dot material, and a preparation method and application thereof. Background The carbon dot material with the nano-scale size has the characteristics of low cost, low toxicity, simple preparation method, adjustable and stable fluorescence spectrum and the like, has potential application prospect in various fields, particularly has rapid development in the aspects of photoelectric devices, sensing, biological imaging, file security and the like, and attracts wide attention. For each application field, the high quantum efficiency is the basic characteristic which the carbon dot must possess, so that not only can the use cost be saved, but also the use effect can be improved. Therefore, the preparation of carbon dots with high quantum efficiency is a fundamental condition for promoting industrialization thereof. At present, various methods for preparing carbon dots exist, but the quantum efficiency of the carbon dots prepared by the methods is close to 100% but the number of the branches is increased, and the fluorescence ranges of the high quantum efficiency carbon dots prepared by the methods are only blue light, green light and yellow light, and the quantum efficiency distances of the carbon dots in the red light range are still obviously different from 100%. Among the red light carbon dot materials which have been reported at present, there are only three types of materials having high quantum efficiency exceeding 80%, namely carbon dots having a quantum efficiency of 80% obtained by hydrothermal reaction of flowers as a raw material in a nitric acid solution, carbon dots having a quantum efficiency of 86% obtained by solvothermal reaction of N, N-dipropyl-p-phenylenediamine as a raw material in an N, N-dimethylacetamide solution, and carbon dots having a quantum efficiency of 84% obtained by hydrothermal reaction of tris (4-aminophenyl) amine as a raw material in a hydrochloric acid aqueous solution. It can be seen that the quantum efficiency of the red fluorescent carbon dots has room for improvement, and raw materials with certain dangers, such as perylene belonging to three types of carcinogens and N, N-dipropyl p-phenylenediamine, are used, so that the red fluorescent carbon dots have certain toxicity. Therefore, the development of a simple, feasible and environment-friendly method for preparing the red fluorescent carbon dots with higher quantum efficiency has important scientific research and practical value. Disclosure of Invention The invention aims to overcome the defects in the prior art and provide a carbon dot material which emits red fluorescence and has quantum efficiency of more than 90% and a preparation method thereof, so as to solve the technical problem of low quantum efficiency of the fluorescent carbon dot material prepared by the prior method. In order to achieve the aim of the invention, one aspect of the invention provides a preparation method of a fluorescent carbon dot material. The preparation method of the fluorescent carbon dot material comprises the following steps: Dissolving 8-hydroxy julolidine-9-formaldehyde and citric acid in water in proportion to prepare a mixture solution, carrying out hydrothermal reaction treatment on the mixture solution in a sealed environment, and then carrying out purification treatment. In another aspect of the invention, a fluorescent carbon dot material is provided. The fluorescent carbon dot material is formed by growing the preparation method of the fluorescent carbon dot material. In yet another aspect of the invention, there is provided the use of the fluorescent carbon dot material of the invention. The fluorescent carbon dot material has potential application in the aspects of targeting and imaging of mitochondria. Compared with the prior art, the preparation method of the room-temperature phosphorescent carbon dot material takes 8-hydroxyjulolidine-9-formaldehyde and citric acid as raw materials, and adopts a hydrothermal method to directly prepare the fluorescent carbon dot material, so that on one hand, the preparation method has the advantages of easily controlled process conditions, reduced economic cost, and can ensure the stability of the prepared fluorescent carbon dot material such as particle size, phosphorescent property and the like, and on the other hand, the prepared fluorescent carbon dot material has high quantum efficiency, stable optical property, low toxicity and good biocompatibility. Drawings FIG. 1 is a schematic flow chart of a method for preparing a fluorescent carbon dot material according to an embodiment of the present invention; FIG. 2 is a transmission electron microscope image of a fluorescent carbon dot material according to an embodiment of the present invention; FIG. 3 is a high resolution tra