CN112251218A - Preparation method of ethylenediamine functionalized carbon quantum dots and application of ethylenediamine functionalized carbon quantum dots in catechol detection - Google Patents
Preparation method of ethylenediamine functionalized carbon quantum dots and application of ethylenediamine functionalized carbon quantum dots in catechol detection Download PDFInfo
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Abstract
The invention provides a preparation method of ethylenediamine functionalized carbon quantum dots and application of the ethylenediamine functionalized carbon quantum dots in catechol detection. The ethylenediamine is introduced to the surface of the carbon quantum dot through an amidation reaction and a protection/deprotection method to synthesize the ethylenediamine functionalized carbon quantum dot, the preparation process is simple, the raw material source is wide, the price is low, and the obtained compound has the selective binding function of the target detection object. In a neutral environment, catechol can rapidly react with ethylenediamine on the surface of the ethylenediamine functionalized carbon quantum dot to generate a static compound, and the static compound causes synchronous quenching of nuclear state and surface state fluorescence of the ethylenediamine functionalized carbon quantum dot. The catechol concentration and the fluorescence quenching value of the ethylenediamine functionalized carbon quantum dot present a good linear relation, and the detection limit reaches 0.07 mg/L. The invention establishes a simple and rapid catechol fluorescence quantitative analysis method, and has extremely high selectivity and anti-interference performance for detecting catechol.
Description
Technical Field
The invention belongs to the technical field of preparation of carbon nano material fluorescent probes and detection of organic pollutants, and particularly relates to a preparation method of ethylenediamine functionalized carbon quantum dots and application of the ethylenediamine functionalized carbon quantum dots in catechol detection.
Background
Catechol is widely used as an organic raw material for producing drugs, light stabilizers, insecticides, antioxidants, dyes, and the like. In the production and application process, the water-soluble organic fertilizer easily enters the environmental water body and causes serious harm to the health and the ecological environment of a human body at very low concentration. The resorcinol and the hydroquinone which are taken as isomers of the catechol have similar structures with the catechol, and the resorcinol and the hydroquinone often coexist in water. Therefore, establishing a high-selectivity detection method for quantitatively analyzing catechol has important practical significance. At present, various analytical methods have been applied to the quantitative detection of catechol, such as high performance liquid chromatography, spectroscopy, gas chromatography/mass spectrometry, chemical fluorescence, electrochemical detection, and the like. Most of these methods require expensive instrumentation, time consuming and complex pre-treatment steps. Therefore, it is still necessary to develop a new quantitative analysis technique for catechol detection which is fast and convenient.
In recent years, fluorescence detection methods have gained increasing attention from researchers due to their extremely high detection sensitivity, simple analytical procedures, and the need for relatively inexpensive detection instruments. Compared with organic or inorganic fluorescent probes such as cadmium telluride quantum dots, furan red, calcium red and the like, carbon quantum dots with high fluorescence stability, photobleaching resistance, wide and continuous excitation light, adjustable emitted light, good biocompatibility and other excellent performances are favored in the field of fluorescence analysis. Carbon quantum dots have been used to detect various metal ions and organic molecules by analyzing changes in their fluorescence intensity, but studies on the analysis of catechol using carbon quantum dots have been rarely reported. The existence of isomers with similar structures is easy to interfere the detection of catechol; in addition, the design of fluorescent probes based on carbon quantum dots generally selects the maximum excitation wavelength (mostly around 360 nm) or the maximum emission wavelength as the detection wavelength. In fact, the fluorescence of carbon quantum dots has a plurality of complex sources, and the change of fluorescence signals is closely related to different luminescent sites (such as sp2 carbon nucleus, surface defect and the like) and corresponding excitation wavelengths. If the relationship between the change of the fluorescence of the carbon quantum dot caused by the target analyte and the fluorescence emission site inside the carbon quantum dot can be found, not only can better detection conditions be found conveniently, but also a more efficient and anti-interference detection method can be established.
Disclosure of Invention
In view of the above, the invention aims to provide a preparation method of an ethylenediamine functionalized carbon quantum dot and an application of the ethylenediamine functionalized carbon quantum dot in catechol detection. Within a certain range, the catechol concentration and the fluorescence quenching value of the ethylenediamine functionalized carbon quantum dot present a good linear relationship, and the functionalized carbon quantum dot probe shows extremely high selectivity and anti-interference performance on detection of catechol when various other organic pollutants and various anions and cations coexist.
The invention modifies ethylenediamine on the surface of the carbon quantum dot through a protection/deprotection method and an amidation reaction to obtain the functionalized carbon quantum dot. The ethylenediamine molecule reserved amino end on the ethylenediamine functionalized carbon quantum dot can rapidly and chemically react with pyrocatechol in a solution to generate a static compound, so that the fluorescence of the kernel state and the surface state of the ethylenediamine functionalized carbon quantum dot is effectively quenched, and a simple and rapid pyrocatechol fluorescence quantitative analysis method with high sensitivity and selectivity is successfully established on the basis of selecting the kernel state corresponding to the excitation wavelength which has the excitation wavelength independence and a narrower emission peak.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
a preparation method of ethylenediamine functionalized carbon quantum dots comprises the following steps:
(1) dissolving citric acid and urea in ethylene glycol, stirring, heating, filtering, dialyzing with deionized water as dialysis external liquid, and freeze-drying the dialysate to obtain carbon quantum dot powder;
(2) adding the carbon quantum dot powder obtained in the step (1) into a 2- (N-morpholine) ethanesulfonic acid buffer solution, and introducing nitrogen after ultrasonic dispersion;
(3) adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and hydroxysuccinimide into the solution obtained in the step (2) at the temperature of 0 ℃ under the environmental condition, continuously introducing nitrogen, and stirring;
(4) adding tert-butoxycarbonylethylenediamine into the solution of the step (3) at 0 ℃ under the nitrogen atmosphere, adding a sodium hydroxide solution, adjusting the pH value, and stirring;
(5) adding a certain amount of hydrochloric acid into the solution obtained in the step (4), and continuously stirring;
(6) adding sodium bicarbonate powder into the solution obtained in the step (5), adjusting the pH of the solution, and dialyzing by taking deionized water as dialysis external liquid;
(7) and (4) freeze-drying the dialysate obtained in the step (6) to obtain ethylenediamine functionalized carbon quantum dot powder.
Preferably, in the step (1), the molar ratio of the citric acid to the urea to the ethylene glycol is 1: (1-3): (40 to 80), preferably, 1: (1.5-2.5): (50-60); the heating temperature is 120-240 ℃, and the heating time is 2-24 hours, preferably 8-16 hours; the diameter of a filter membrane used for filtering is 0.1-0.5 mu m, and the amount of dialysis external liquid deionized water used for dialysis is 800-1500 mL; the dialysis time is 2-72 h, preferably 12-48 h; the dialysis external liquid is replaced for 2-4 times every 24 hours, and the freeze drying time is 12-48 hours.
Preferably, in the step (2), the volume ratio of the mass of the carbon quantum dot powder to the volume of the 2- (N-morpholine) ethanesulfonic acid buffer solution is 1 mg: (0.5-2.0) mL, preferably, the pH value of the ethanesulfonic acid buffer solution is 6, the ultrasonic time is 5-60 min, and the nitrogen gas introduction time is 10-60 min.
Preferably, in the step (3), the mass ratio of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and the hydroxysuccinimide to the carbon quantum dot powder used in the step (2) is (2-5): (0.2-10): 1-stirring time is 2-24 h, preferably 8-16 h.
Preferably, in the step (4), the mass ratio of the volume of the added tert-butoxycarbonylethylenediamine to the carbon quantum dots in the step (2) is (5-10) μ L: 1mg, wherein the adding amount of the sodium hydroxide solution depends on the pH value of the solution, the sodium hydroxide solution is stopped to be added when the pH value of the solution is 7.2-7.8, and the stirring time is 2-48 h.
Preferably, in the step (5), the mass ratio of the volume of the added hydrochloric acid (1M) to the carbon quantum dots in the step two is (0.2-1) mL: 1mg, and the stirring time is 1-6 h.
Preferably, in the step (6), the amount of sodium bicarbonate powder is added to adjust the pH to 6, the amount of deionized water used for dialyzing the external liquid is 800-1600 mL, and the dialysis time is 2-72 hours; preferably, 12 to 48 hours.
Preferably, the freeze-drying time in the step (7) is 12-48 h.
The invention provides application of the ethylenediamine functionalized carbon quantum dot prepared by the preparation method in catechol detection.
Preferably, the fluorescence emission of the sample is tested using a fluorescence spectrometer with an excitation wavelength of 310 nm; preferably, the concentration of the ethylenediamine functionalized carbon quantum dots is 0.01-0.05g/L during detection.
The mechanism of the invention is as follows: after the surface of the carbon quantum dot is modified with ethylenediamine, the connected ethylenediamine can be combined with pyrocatechol in a solution through Michael addition reaction or Schiff base reaction to generate a static compound, and the static compound can be used as an electron donor to transfer electrons of the static compound to a surface luminescence site of the functionalized carbon quantum dot in an excited state and inhibit radiative recombination of excited carriers. The ethylenediamine functional carbon quantum dot comprises three luminescent sites of a kernel state, an edge state and a surface state, excited-state electrons of the kernel state are easily captured by defects of the surface state and are radiatively compounded after the kernel state is excited, so that fluorescence generated by the kernel state and the surface state is easily influenced by the external environment, the surface state and the kernel state of the ethylenediamine functional carbon quantum dot are synchronously quenched under the action of catechol, and excited-state electrons of the edge state are mainly compounded in the edge state, so that the ethylenediamine functional carbon quantum dot has certain fluorescent response inert characteristics.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) in the carbon quantum dot functionalization process, an amino group at one end of an ethylenediamine molecule is protected and then loaded on the surface of the carbon quantum dot through amidation reaction, and then deprotection is carried out, so that effective combination of ethylenediamine and the carbon quantum dot can be ensured, and free amino at the other end can be provided to combine with a target analyte.
(2) The ethylenediamine molecules on the prepared ethylenediamine functionalized carbon quantum dots can rapidly and chemically react with pyrocatechol in a solution to generate a static compound, so that the fluorescence of the carbon quantum dot probe is effectively quenched, and a simple and rapid pyrocatechol fluorescence quantitative analysis method is established based on the static compound.
(3) The 310nm which has stronger fluorescence intensity, excitation wavelength independence and narrower emission peak and corresponds to kernel-state luminescence is selected as the excitation wavelength, the fluorescence quenching rate of the functionalized carbon quantum dot and the concentration of catechol show good linear relation, and the detection effect of methods such as electrochemistry or HPLC can be achieved on the actual water body.
(4) The ethylene diamine functionalized carbon quantum dot based probe has extremely high selectivity for fluorescence detection of catechol, and has interference resistance to isomers of the catechol, other various organic matters and anions and cations.
Drawings
FIG. 1 is a three-dimensional fluorescence scanning spectrum of the ethylenediamine-functionalized carbon quantum dot (excitation wavelength range: 200-;
FIG. 2(a) is a fluorescence emission spectrum curve of the ethylenediamine-functionalized carbon quantum dots after adding different concentrations of catechol, and (b) is a linear relationship between the quenching rate (F0-F)/F and the catechol concentration;
FIG. 3 shows quenching rates of catechol, resorcinol, and hydroquinone to ethylene diamine functionalized carbon quantum dots under different excitation wavelengths;
FIG. 4 shows the effect of (a) different organic compounds and (b) different anions and pyrocatechol on the fluorescence quenching rate of ethylenediamine-functionalized carbon quantum dots.
Detailed Description
Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods are conventional methods unless otherwise specified.
The present invention will be described in detail with reference to examples.
(1) Preparation of ethylenediamine functionalized carbon quantum dots
Dissolving 0.65g of citric acid and 0.42g of urea in 25mL of ethylene glycol, magnetically stirring for 2 hours, heating at 200 ℃ for 10 hours, cooling to room temperature, filtering, dialyzing, and freeze-drying to obtain carbon quantum dot powder. 20mg of the carbon quantum dot powder was further added to 20mL of MES buffer (pH 6), and after 40 minutes of ultrasonic dispersion, nitrogen gas was introduced for 30 minutes to remove dissolved oxygen in the solution, after which the solution was placed in an ice bath container and 120mg of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and 60mg of hydroxysuccinimide were added in this order, and the reaction was continued under a nitrogen atmosphere and stirred at a constant speed for 12 hours using a magnetic stirrer to ensure the reaction. mu.L of t-butyloxycarbonyl ethylenediamine was added under nitrogen at low temperature of 0 ℃ and a little sodium hydroxide solution (1M) was slowly added dropwise to the solution to adjust the pH of the solution to neutral conditions of about 7.4. Stirring is continued for 24 hours at a constant speed to ensure that the tert-butoxycarbonyl ethylenediamine is fully and covalently connected to the surface of the carbon quantum dot. 10mL of hydrochloric acid (1M) was then added to the solution and stirring was continued at room temperature for 3 hours. Adding sodium bicarbonate powder to neutralize excessive hydrochloric acid in the solution, dialyzing with 800mL of deionized water as external liquid for 48 hours to remove various solutes in the mixed solution after the pH value of the solution reaches 6, and freeze-drying after dialysis to obtain the ethylenediamine functionalized carbon quantum dot powder. Fig. 1 is a three-dimensional fluorescence scanning spectrum of the ethylenediamine functionalized carbon quantum dot, and it can be seen that the quantum dot has three fluorescence regions corresponding to a core state, an edge state and a surface state respectively.
(2) Detection of ethylenediamine functionalized carbon quantum dots on catechol
1mL of ethylenediamine-functionalized carbon quantum dot dispersion is injected into a 10mL sample bottle, diluted by 8mL of PBS buffer (0.01M, pH 7.4), and then 1mL of catechol solutions with different concentrations are added into the bottle, and the bottle is shaken uniformly and then kept stand at room temperature for 30 min. Fluorescence measurements (excitation wavelength 310nm) were performed on different samples using a fluorescence spectrometer.
Example 1
1mL of ethylenediamine-functionalized carbon quantum dot dispersion (0.1g/L) was put into a 10mL sample bottle, 8mL of PBS buffer (0.01M, pH 7.4) was added, 1mL of catechol solutions with different concentrations were added, the mixture was shaken to be uniform and then allowed to stand at room temperature for 30min, and fluorescence was measured using a fluorescence spectrometer.
Example 2
1mL of ethylenediamine-functionalized carbon quantum dot dispersion (0.2g/L) was put into a 10mL sample bottle, 8mL of PBS buffer (0.01M, pH 7.4) was added, 1mL of catechol solutions with different concentrations were added, the mixture was shaken to be uniform and then allowed to stand at room temperature for 30min, and fluorescence was measured using a fluorescence spectrometer.
Example 3
1mL of ethylenediamine-functionalized carbon quantum dot dispersion (0.3g/L) was put into a 10mL sample bottle, 8mL of PBS buffer (0.01M, pH 7.4) was added, 1mL of catechol solutions with different concentrations were added, the mixture was shaken to be uniform and then allowed to stand at room temperature for 30min, and fluorescence was measured using a fluorescence spectrometer.
Example 4
1mL of ethylenediamine-functionalized carbon quantum dot dispersion (0.4g/L) was put into a 10mL sample bottle, 8mL of PBS buffer (0.01M, pH 7.4) was added, 1mL of catechol solutions with different concentrations were added, the mixture was shaken to be uniform and then allowed to stand at room temperature for 30min, and fluorescence was measured using a fluorescence spectrometer.
Example 5
1mL of ethylenediamine-functionalized carbon quantum dot dispersion (0.5g/L) was put into a 10mL sample bottle, 8mL of PBS buffer (0.01M, pH 7.4) was added, 1mL of catechol solutions with different concentrations were added, the mixture was shaken to be uniform and then allowed to stand at room temperature for 30min, and fluorescence was measured using a fluorescence spectrometer.
FIG. 2 shows fluorescence emission spectrum curves and quenching rates (F) of ethylenediamine-functionalized carbon quantum dots with different concentrations of catechol0Linear relationship between-F)/F and catechol concentration (F)0And F respectively refer to the fluorescence intensity of the ethylenediamine-functionalized carbon quantum dot when no catechol was added and the fluorescence intensity of the ethylenediamine-functionalized carbon quantum dot after catechol was added). When in useWhen the concentration of the catechol is within the range of 2-40 mu M, the linear regression equation is that Y is 0.0494+0.00855X, and the correlation coefficient R is2At 0.995, the detection limit was 0.65. mu.M (0.07 mg/L).
Comparative example 1
Injecting 1mL of ethylenediamine functionalized carbon quantum dots into a 10mL sample bottle, adding 8mL of PBS buffer solution (0.01M, pH 7.4), respectively injecting 1mL of 100 μ M catechol, resorcinol and hydroquinone solution, oscillating uniformly, standing at room temperature for 30min, performing spectrum test by using a fluorescence spectrometer at the excitation wavelengths of 310nm, 370nm and 460nm, and respectively calculating the quenching rates of the catechol, the resorcinol and the hydroquinone on the ethylenediamine functionalized carbon quantum dots at different excitation wavelengths.
FIG. 3 shows the quenching rates of catechol, resorcinol, and hydroquinone for ethylene diamine functionalized carbon quantum dots at excitation wavelengths corresponding to a core state (310nm), a rim state (370nm), and a surface state (460 nm). It can be seen that the fluorescence emission of the carbon core state and the surface state exhibit a consistent fluorescence response behavior, and the edge state emission exhibits an "inert" character.
Comparative example 2
1mL of ethylenediamine was put into a 10mL sample bottle, 8mL of PBS buffer (0.01M, pH 7.4) was added, 1mL of a 50. mu.M catechol solution was added, and 1mL of 50. mu.M resorcinol, hydroquinone, phenol, acetic acid, benzoic acid, p-aminophenol, oxytetracycline, tryptophan, lysine, tyrosine, or 10. mu.M Ba was added2+、Ca2+、C2O7 2-、Cu2+、Fe2+、Fe3+、K+、Mg2+、NH4 +、SiO3 2-、Zn2+、Cl-、Na+、SO4 2-、NO3-,、Co2+、Cr3+、Al3+And (3) waiting for anions and cations, oscillating uniformly, standing for 30min at room temperature, and performing fluorescence test by using a fluorescence spectrometer at an excitation wavelength of 310 nm.
FIG. 4 shows the effect of different organic substances, anions and cations on the fluorescence quenching rate of ethylenediamine-functionalized carbon quantum dots in the presence of catechol. After the interferent and catechol are added into the detection system of the ethylenediamine functionalized carbon quantum dot, the fluorescence quenching rate of the quantum dot is basically consistent with the quenching rate of the catechol existing alone, which shows that the ethylenediamine functionalized carbon quantum dot system has good selective detection capability and anti-interference performance on the catechol.
Comparative example 3
Tap water and effluent from a sewage treatment plant are collected, impurities are removed by filtering through a 0.22 mu M filter membrane, pyrocatechol (6 mu M, 10 mu M and 25 mu M) with three different concentrations is added into each water body, 1mL of ethylenediamine functionalized carbon quantum dots are injected into a 10mL sample bottle, 8mL of PBS buffer solution (0.01M, pH 7.4) is added, 1mL of water sample is respectively injected, the mixture is uniformly oscillated and then stands for 30min at room temperature, and a fluorescence spectrometer is used for performing spectrum test under the excitation wavelength of 310 nm.
Table 1 shows the evaluation of the detection effect of the ethylenediamine functionalized carbon quantum dots on catechol in the actual water body using the standard addition recovery method. The catechol recovery was measured to be in the range of 93.36% to 127.54% and the Relative Standard Deviation (RSD) was in the range of 2.44% to 8.39%. The system is suitable for measuring catechol in natural water sample and has good repeatability.
TABLE 1
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, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. A preparation method of ethylenediamine functionalized carbon quantum dots is characterized by comprising the following steps: the method comprises the following steps:
(1) dissolving citric acid and urea in ethylene glycol, stirring, heating, filtering, dialyzing with deionized water as dialysis external liquid, and freeze-drying the dialysate to obtain carbon quantum dot powder;
(2) adding the carbon quantum dot powder obtained in the step (1) into a 2- (N-morpholine) ethanesulfonic acid buffer solution, and introducing nitrogen after ultrasonic dispersion;
(3) adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and hydroxysuccinimide into the solution obtained in the step (2) at the temperature of 0 ℃ under the environmental condition, continuously introducing nitrogen, and stirring;
(4) adding tert-butoxycarbonylethylenediamine into the solution of the step (3) at 0 ℃ under the nitrogen atmosphere, adding a sodium hydroxide solution, adjusting the pH value, and stirring;
(5) adding a certain amount of hydrochloric acid into the solution obtained in the step (4), and continuously stirring;
(6) adding sodium bicarbonate powder into the solution obtained in the step (5), adjusting the pH of the solution, and dialyzing by taking deionized water as dialysis external liquid;
(7) and (4) freeze-drying the dialysate obtained in the step (6) to obtain ethylenediamine functionalized carbon quantum dot powder.
2. The method for preparing the ethylenediamine functionalized carbon quantum dot according to claim 1, wherein the method comprises the following steps: in the step (1), the molar ratio of the citric acid to the urea to the glycol is 1: (1-3): (40 to 80), preferably, 1: (1.5-2.5): (50-60); the heating temperature is 120-240 ℃, and the heating time is 2-24 hours, preferably 8-16 hours; the diameter of a filter membrane used for filtering is 0.1-0.5 mu m, and the amount of dialysis external liquid deionized water used for dialysis is 800-1500 mL; the dialysis time is 2-72 h, preferably 12-48 h; the dialysis external liquid is replaced for 2-4 times every 24 hours, and the freeze drying time is 12-48 hours.
3. The method for preparing the ethylenediamine functionalized carbon quantum dot according to claim 1, wherein the method comprises the following steps: in the step (2), the volume ratio of the mass of the carbon quantum dot powder to the volume of the 2- (N-morpholine) ethanesulfonic acid buffer solution is 1 mg: (0.5-2.0) mL, preferably, the pH value of the ethanesulfonic acid buffer solution is 6, the ultrasonic time is 5-60 min, and the nitrogen gas introduction time is 10-60 min.
4. The method for preparing the ethylenediamine functionalized carbon quantum dot according to claim 1, wherein the method comprises the following steps: in the step (3), the mass ratio of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and the hydroxysuccinimide to the carbon quantum dot powder used in the step (2) is (2-5): (0.2-10): 1, the stirring time is 2-24 h, and the preferable time is 8-16 h.
5. The method for preparing the ethylenediamine functionalized carbon quantum dot according to claim 1, wherein the method comprises the following steps: in the step (4), the mass ratio of the volume of the added tert-butoxycarbonylethylenediamine to the carbon quantum dots in the step (2) is (5-10) mu L: 1mg, wherein the adding amount of the sodium hydroxide solution depends on the pH value of the solution, the sodium hydroxide solution is stopped to be added when the pH value of the solution is 7.2-7.8, and the stirring time is 2-48 h.
6. The method for preparing the ethylenediamine functionalized carbon quantum dot according to claim 1, wherein the method comprises the following steps: in the step (5), the mass ratio of the volume of the added hydrochloric acid (1M) to the carbon quantum dots in the step two is (0.2-1) mL: 1mg, and the stirring time is 1-6 h.
7. The method for preparing the ethylenediamine functionalized carbon quantum dot according to claim 1, wherein the method comprises the following steps: in the step (6), adding sodium bicarbonate powder to adjust the pH to 6, wherein the deionized water used for dialyzing the external liquid is 800-1600 mL, and the dialysis time is 2-72 h; preferably, 12 to 48 hours.
8. The method for preparing the ethylenediamine functionalized carbon quantum dot according to claim 1, wherein the method comprises the following steps: the freeze drying time in the step (7) is 12-48 h.
9. The application of the ethylenediamine functionalized carbon quantum dot prepared by the preparation method of any one of claims 1 to 8 in catechol detection.
10. Use according to claim 9, characterized in that: with 310nm as an excitation wavelength, testing the fluorescence emission of the sample by using a fluorescence spectrometer; preferably, the concentration of the ethylenediamine functionalized carbon quantum dots is 0.01-0.05g/L during detection.
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|---|---|---|---|---|
| CN113607709A (en) * | 2021-08-10 | 2021-11-05 | 河北科技大学 | Application of fluorescent carbon quantum dots in naphthenic acid detection and naphthenic acid detection method |
| CN114735674A (en) * | 2022-05-09 | 2022-07-12 | 辽宁大学 | Carbon quantum dot capable of releasing hydrogen sulfide gas and preparation method thereof |
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| CN113607709A (en) * | 2021-08-10 | 2021-11-05 | 河北科技大学 | Application of fluorescent carbon quantum dots in naphthenic acid detection and naphthenic acid detection method |
| CN113607709B (en) * | 2021-08-10 | 2024-05-10 | 河北科技大学 | Application of fluorescent carbon quantum dot in detection of naphthenic acid and detection method of naphthenic acid |
| CN114735674A (en) * | 2022-05-09 | 2022-07-12 | 辽宁大学 | Carbon quantum dot capable of releasing hydrogen sulfide gas and preparation method thereof |
| CN114735674B (en) * | 2022-05-09 | 2023-12-08 | 辽宁大学 | Carbon quantum dot capable of releasing hydrogen sulfide gas and preparation method thereof |
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| CN112251218B (en) | 2023-02-17 |
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