Preparation and fluorescence regulation method of water-soluble nontoxic carbon quantum dots

Abstract

The invention discloses a preparation and a fluorescence regulation method of water-soluble non-toxic carbon quantum dots. The method comprises the following steps: 1) preparing a carbon quantum dot precursor solution; 2) preparing carbon quantum dots: transferring the precursor solution into a reaction kettle, performing a reaction at 200 DEG C for 24 h, performing natural cooling after reaction,and performing purification by a dialysis bag to obtain the carbon quantum dots; and 3) performing a fluorescence regulation process: regulating the B and N doped carbon quantum dots to emit light byutilizing the pH value and the filling degree of the reaction kettle to prepare the carbon quantum dots with different fluorescence wavelengths and different light emitting intensities. The method has the advantages of simplicity in operation, and low operation process difficulty, and the fluorescence wavelength of the obtained carbon quantum dots does not change along with the change of excitinglight energy.

Description

[0001] The invention relates to a method for preparing water-soluble non-toxic carbon quantum dots and a method for regulating fluorescence, and belongs to the field of water-soluble fluorescent quantum dot materials and applications. Background technique

[0002] Due to their outstanding advantages in light emission, stability, biocompatibility, and low cost, carbon quantum dots have been extensively studied in the past decade. Carbon quantum dots can be used to assemble fluorescent probes, light-emitting devices and biosensors. The preparation method of carbon quantum dots has also been developed. Laser ablation, pyrolysis, electrochemical oxidation, hydrothermal reaction and microwave treatment can all synthesize carbon quantum dots. The photoluminescence spectrum of carbon quantum dots is wide, and the luminescence wavelength moves with the change of excitation light energy, and the maximum value is in the blue region. In addition, the absorption curves of carbon quantum ...

Examples

Embodiment 1

[0028] A kind of preparation method of water-soluble non-toxic carbon quantum dot

[0029] 1) Change CH 4 N 2 O (0.5 g) was added to 5 mL of deionized water, H 3 BO 3 (0.25g) into 5mL of ethanol;

[0030] 2) Mix the two, add 5mL of 10% ammonia solution, and sonicate for 10min;

[0031] 3) Transfer the sonicated solution into a 50mL and tetrafluoroethylene liner, react in the reactor at 200°C for 24h, cool to room temperature naturally after the reaction, centrifuge the product at 6500rmp / min for 10min, and take The supernatant, the supernatant was dialyzed in a dialysis bag with a molecular weight of 1000Da for 24 hours to obtain the product.

Embodiment 2

[0033] Quantum dots were prepared by using a method for preparing water-soluble non-toxic carbon quantum dots (Example 1), and B and N-doped carbon quantum dots with different fluorescence wavelengths were obtained by changing the pH value.

[0034] Carbon quantum dots with ultraviolet wavelength: the reaction temperature is 200°C, the reaction time is 24h, the pH value of the solution is 13, the amount of boric acid added is 4mmol, the amount of urea added is 8mmol, and the solution volume is 17mL.

[0035] Carbon quantum dots with ultraviolet / blue wavelength coexistence: the reaction temperature is 200°C, the reaction time is 24h, the pH value of the solution is 7, the amount of boric acid added is 4mmol, the amount of urea added is 8mmol, and the solution volume is 17mL.

[0036] Blue wavelength carbon quantum dots: the reaction temperature is 200°C, the reaction time is 24h, the pH value of the solution is 1, the amount of boric acid added is 4mmol, the amount of urea added...

Embodiment 3

[0038] Quantum dots were prepared by using a method for preparing water-soluble non-toxic carbon quantum dots (Example 1), and B and N-doped carbon quantum dots with different fluorescence intensities were obtained by changing the filling degree of the reactor.

[0039] Adjust the pH of boric acid and urea precursors to 1, take 5mL, 10mL, 20mL, and 30mL respectively, add them to a 50mL polytetrafluoroethylene liner, and react at 200°C for 24h to obtain the product.

[0040] figure 1 It is an unregulated carbon quantum dot spectrum. It can be seen that the fluorescence wavelength moves with the change of excitation light, and the fluorescence intensity is low.

[0041] figure 2 , image 3 , Figure 4 They are the fluorescence spectra of carbon quantum dots after regulation. It can be clearly seen that the fluorescence wavelength shows a relatively regular change. When the pH value is 1, it shows a luminescence peak at 450nm, and the fluorescence does not move with the cha...

[0001] The invention relates to a method for preparing water-soluble non-toxic carbon quantum dots and a method for regulating fluorescence, and belongs to the field of water-soluble fluorescent quantum dot materials and applications. Background technique

[0002] Due to their outstanding advantages in light emission, stability, biocompatibility, and low cost, carbon quantum dots have been extensively studied in the past decade. Carbon quantum dots can be used to assemble fluorescent probes, light-emitting devices and biosensors. The preparation method of carbon quantum dots has also been developed. Laser ablation, pyrolysis, electrochemical oxidation, hydrothermal reaction and microwave treatment can all synthesize carbon quantum dots. The photoluminescence spectrum of carbon quantum dots is wide, and the luminescence wavelength moves with the change of excitation light energy, and the maximum value is in the blue region. In addition, the absorption curves of carbon quantum ...

Examples

Embodiment 1

[0028] A kind of preparation method of water-soluble non-toxic carbon quantum dot

[0029] 1) Change CH 4 N 2 O (0.5 g) was added to 5 mL of deionized water, H 3 BO 3 (0.25g) into 5mL of ethanol;

[0030] 2) Mix the two, add 5mL of 10% ammonia solution, and sonicate for 10min;

[0031] 3) Transfer the sonicated solution into a 50mL and tetrafluoroethylene liner, react in the reactor at 200°C for 24h, cool to room temperature naturally after the reaction, centrifuge the product at 6500rmp / min for 10min, and take The supernatant, the supernatant was dialyzed in a dialysis bag with a molecular weight of 1000Da for 24 hours to obtain the product.

Embodiment 2

[0033] Quantum dots were prepared by using a method for preparing water-soluble non-toxic carbon quantum dots (Example 1), and B and N-doped carbon quantum dots with different fluorescence wavelengths were obtained by changing the pH value.

[0034] Carbon quantum dots with ultraviolet wavelength: the reaction temperature is 200°C, the reaction time is 24h, the pH value of the solution is 13, the amount of boric acid added is 4mmol, the amount of urea added is 8mmol, and the solution volume is 17mL.

[0035] Carbon quantum dots with ultraviolet / blue wavelength coexistence: the reaction temperature is 200°C, the reaction time is 24h, the pH value of the solution is 7, the amount of boric acid added is 4mmol, the amount of urea added is 8mmol, and the solution volume is 17mL.

[0036] Blue wavelength carbon quantum dots: the reaction temperature is 200°C, the reaction time is 24h, the pH value of the solution is 1, the amount of boric acid added is 4mmol, the amount of urea added...

Embodiment 3

[0038] Quantum dots were prepared by using a method for preparing water-soluble non-toxic carbon quantum dots (Example 1), and B and N-doped carbon quantum dots with different fluorescence intensities were obtained by changing the filling degree of the reactor.

[0039] Adjust the pH of boric acid and urea precursors to 1, take 5mL, 10mL, 20mL, and 30mL respectively, add them to a 50mL polytetrafluoroethylene liner, and react at 200°C for 24h to obtain the product.

[0040] figure 1 It is an unregulated carbon quantum dot spectrum. It can be seen that the fluorescence wavelength moves with the change of excitation light, and the fluorescence intensity is low.

[0041] figure 2 , image 3 , Figure 4 They are the fluorescence spectra of carbon quantum dots after regulation. It can be clearly seen that the fluorescence wavelength shows a relatively regular change. When the pH value is 1, it shows a luminescence peak at 450nm, and the fluorescence does not move with the cha...

Images