CN111187618A

CN111187618A - Orange fluorescent carbon quantum dot and preparation method and application thereof

Info

Publication number: CN111187618A
Application number: CN202010033081.0A
Authority: CN
Inventors: 孟雅婷; 焦媛; 张羱; 刘洋; 弓晓娟; 双少敏; 董川
Original assignee: Shanxi University
Current assignee: Shanxi University
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2020-05-22
Anticipated expiration: 2040-01-13
Also published as: CN111187618B

Abstract

The invention provides an orange fluorescent carbon quantum dot and a preparation method and application thereof, wherein the preparation method of the carbon quantum dot comprises the following steps: dissolving 0.02-0.30g of crocus sativus red in 20mL of ethanol at room temperature, transferring the solution to a 50mL hydrothermal reaction kettle, reacting for 2-7 hours at 150-250 ℃, and filtering insoluble substances to obtain a red solution; dialyzing in a container for at least 3 days by a dialysis bag of 500-1000 Da to obtain a pure water solution of the carbon quantum dots; and freeze-drying the carbon quantum dots to obtain the target carbon quantum dots. The method has simple preparation process, wide raw material source, easy price, low requirement for preparation conditions, and obtained carbonThe quantum yield of the quantum dots is high. The prepared carbon quantum dots are used as fluorescent probes for ONOO^‑The method can also be applied to living cell fluorescence imaging.

Description

Orange fluorescent carbon quantum dot and preparation method and application thereof

Technical Field

The invention relates to a carbon luminescent nano material, in particular to a carbon quantum dot, and specifically relates to an orange fluorescent carbon quantum dot and a preparation method and application thereof.

Background

Peroxynitrite (ONOO) is a well-known per se compound^-) An active oxygen species with strong oxidative and nucleophilic properties is formed by the combination of nitric oxide and superoxide anion radicals under diffusion control, without enzymatic catalysis. Numerous studies have shown that due to the diversity of human diseases, an excess of ONOO^-Will destroy important components of the cell including proteins, DNA and thiols. To date, a variety of materials have been developed for use in ONOO^-Methods of detection such as Electron Paramagnetic Resonance (EPR) spectroscopy, capillary electrophoresis, electrochemical analysis and chromatography. However, there remains a great need for simpler, low cost, efficient and sensitive methods for determining ONOO in biological samples^-。

Disclosure of Invention

The invention aims to provide orange carbon quantum dots and a preparation method thereof.

The invention provides a preparation method of orange fluorescent carbon quantum dots, which comprises the following steps:

dissolving 0.02-0.30g of crocus sativus red in 20mL of ethanol at room temperature, transferring the solution to a 50mL hydrothermal reaction kettle, reacting for 2-7 hours at 150-250 ℃, and filtering insoluble substances to obtain a light red solution; dialyzing in a container for at least 3 days by a dialysis bag of 500-1000 Da to obtain a pure water solution of the carbon quantum dots; and freeze-drying the carbon quantum dots to obtain the target carbon quantum dots.

The preferable saffron red is 0.035-0.25 g;

the reaction temperature is 200-250 ℃, and the reaction time is 5-7 hours.

The carbon quantum dots prepared by the method can be used as fluorescent probes for detecting ONOO in aqueous solution^-The lowest detection limit is 305nmol and the linear range is 6 to 168nmol according to the formula cmin-3 sb/S.

The invention has the beneficial effects that:

the carbon quantum dot solution can be obtained by a one-step hydrothermal method, the synthesis method is simple and effective, the raw materials are cheap and easy to obtain, the reaction conditions are mild, the environment is friendly, the reaction can be completed in a common laboratory, and the method is easy to popularize. The prepared carbon quantum dots can be used as probes for detecting ONOO in aqueous solution^-It can also be used for intracellular ONOO^-Detection of (3).

Drawings

FIG. 1 is a fluorescence emission spectrum of the carbon quantum dot prepared in example 1

FIG. 2 is an infrared spectrum of carbon quantum dots prepared in example 1, in which the abscissa is the detection wavelength and the ordinate is the transmittance

FIG. 3 is ONOO^-Quenching the fluorescence spectrum of the carbon quantum dots prepared in example 1,

FIG. 4 is a spectrum diagram of the change of the fluorescence emission curve of the carbon quantum dots with the excitation wavelength prepared in example 1

FIG. 5 is a graph showing fluorescence lifetime of carbon quantum dots prepared in example 1

FIG. 6 is a carbon quantum dot coating ONOO prepared in example 1^-Quenching laser confocal picture, wherein the cell is a PC-12 cell

Detailed Description

The present invention will be further described with reference to the following drawings and specific examples, which show detailed embodiments and specific procedures, but the scope of the present invention is not limited to the following examples.

Example 1

Step 1, dissolving 0.25g of crocus sativus red in 20mL of ethanol at room temperature, fully stirring, and performing ultrasonic treatment to obtain a clear solution.

Step 2, the solution was transferred to a 50mL hydrothermal reaction kettle.

And 3, placing the hydrothermal kettle in an oven, and reacting for 6 hours at 200 ℃ to obtain a red solution.

And 4, filtering insoluble substances to obtain a red solution. Dialyzing in a glass container for at least 3 days by a dialysis bag of 1000Da to obtain pure water solution of carbon quantum dots.

And 5, freeze-drying the aqueous solution of the fluorescent carbon quantum dots to obtain the fluorescent carbon quantum dots, wherein the relative quantum yield (based on methyl violet) of the fluorescent carbon quantum dots is 30.3%.

The properties are shown in figures 1, 2, 4 and 5. FIG. 1 is a fluorescence emission spectrum of the carbon quantum dot prepared in example 1, and it can be seen that the excitation wavelength of the carbon quantum dot is 545nm and the emission wavelength is 595 nm. FIG. 2 is an infrared spectrum of carbon quantum dots prepared in example 1, and the characteristic peak of N-CDs is located at 3310cm^-1、2961cm^-1、2873cm^-11034 and 1084cm^-1Respectively corresponding to O-H stretching vibration and-NH₂C-H, C ═ C and C-O-C. Fig. 4 is a spectrum diagram of a fluorescence emission curve of the carbon quantum dot prepared in example 1, which has an excitation wavelength independent property, as a function of an excitation wavelength. Fig. 4 is a graph showing the fluorescence lifetime of the carbon quantum dot prepared in example 1, which is 3.46 ns.

Example 2

The procedure of example 1 was repeated except that safranin (0.035 g) was added. The relative quantum yield (based on methyl violet) was 22.6%.

Example 3

The same as in example 1 except that the mass of safranine was 0.07 g. The relative quantum yield (based on methyl violet) was 26.4%.

Example 4

The same as example 1 except that the mass of safranine was 0.21 g. The relative quantum yield (based on methyl violet) was 28.1%.

Example 5

The carbon quantum dot prepared in example 1 was weighed to obtain 4mg, and 4mL of secondary water was added to prepare 1mg/mL carbon dot of mother liquor. 0.5mL of the carbon dot stock solution and 1.5mL of secondary water were added to a fluorescent cuvette, and 10. mu.L of ONOO with different concentrations was added dropwise to the fluorescent cuvette^-(6-168nM) and their fluorescence emission spectra were measured, see FIG. 3.

Example 6

The aqueous solution (0.15mg/mL) of the fluorescent carbon quantum dots prepared in example 1 was used for labeling PC-12 cells, and as shown in FIG. 6, the cell morphology was good, and it was found that the carbon quantum dots were not cytotoxic and could be used for labeling living cells. FIG. 6 is a carbon quantum dot coating ONOO prepared in example 1^-The quenched laser confocal images, from left to right, are: brightfield cytograms (orange), darkfield cytograms (orange), brightfield and darkfield overlay.

Claims

1. A preparation method of orange fluorescent carbon quantum dots is characterized by comprising the following steps:

dissolving 0.02-0.30g of crocus sativus red in 20mL of ethanol at room temperature, transferring the solution to a 50mL hydrothermal reaction kettle, reacting for 2-7 hours at 150-250 ℃, and filtering insoluble substances to obtain a red solution; dialyzing in a container for at least 3 days by a dialysis bag of 500-1000 Da to obtain a pure water solution of the carbon quantum dots; and freeze-drying the carbon quantum dots to obtain the target carbon quantum dots.

2. The method for preparing orange fluorescent carbon quantum dots according to claim 1, wherein the safranin has a mass of 0.035-0.25 g.

3. The method for preparing orange fluorescent carbon quantum dots according to claim 1 or 2, wherein the reaction temperature is 200-250 ℃ and the reaction time is 5-7 hours.

4. The method for preparing orange fluorescent carbon quantum dots according to claim 3, wherein the reaction temperature is 200 ℃ and the reaction time is 6 hours.

5. The fluorescent carbon quantum dots prepared by the method of claim 1, 2 or 4.

6. The use of the fluorescent carbon quantum dots of claim 5 as fluorescent probes for the detection of ONOO-.

7. The use of the fluorescent carbon quantum dots according to claim 5 in the preparation of a reagent for cellular fluorescence imaging.