Preparation method and application of carbon quantum dot-doped fluorescent probe
By preparing boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs), the problem that existing carbon quantum dots cannot effectively detect doxycycline hydrochloride was solved, and rapid and accurate detection of doxycycline hydrochloride was achieved.
Patent Information
- Application Number
- CN202511066390.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-11-11
AI Technical Summary
Existing carbon quantum dots cannot effectively detect doxycycline hydrochloride, and cannot improve detection accuracy and efficiency.
Boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs) were prepared by a one-step hydrothermal method using 3,4-difluorophenylboronic acid and ethylenediamine as precursors. The resulting yellow powder was obtained by filtration through a filter membrane and cooling and drying. This powder was then used for the quantitative detection of doxycycline hydrochloride in water samples.
It achieves rapid and accurate detection of doxycycline hydrochloride, with efficient and stable detection performance and strong anti-interference ability.
Smart Images
Figure CN120924273A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fluorescent probe technology, and in particular to a method for preparing a carbon-doped quantum dot fluorescent probe and its application. Background Technology
[0002] Doxycycline hydrochloride (DOX) belongs to the tetracycline class of antibiotics. These antibiotics exhibit significant inhibitory effects against both Gram-negative and Gram-positive bacteria, and are widely used in clinical medicine and aquaculture due to their broad-spectrum antibacterial activity and affordable price. Doxycycline hydrochloride is not only used for disease prevention and treatment but can also be added to animal feed to promote animal growth, thanks to its significant anti-inflammatory effects, long half-life, and broad-spectrum antibacterial activity. However, high concentrations of doxycycline hydrochloride residues can pose health and environmental risks, such as causing intestinal diseases, liver failure, allergic reactions, and the spread of drug-resistant strains. Therefore, accurate and sensitive detection of doxycycline in complex matrices is crucial. Currently, analytical methods for doxycycline hydrochloride mainly include high-performance liquid chromatography (HPLC), capillary electrophoresis, and immunoassay. These methods offer high selectivity and good separation performance, but typically require significant time, expensive laboratory equipment, and specialized operators.
[0003] Carbon quantum dots (CQDs) are a novel type of carbon nanomaterial developed based on traditional quantum dots. Compared with traditional quantum dots, they have advantages such as low toxicity, good biocompatibility, ease of surface functionalization, and excellent optical properties. Carbon quantum dots have wide applications in fields such as fluorescence sensors, bioimaging, photocatalysis, and drug delivery.
[0004] However, existing carbon quantum dots still cannot effectively detect doxycycline hydrochloride in applications, and cannot improve the detection accuracy and efficiency of doxycycline hydrochloride concentration, which needs to be improved. Summary of the Invention
[0005] In view of this, the first objective of this application is to provide a method for preparing a carbon-doped quantum dot fluorescent probe, so as to obtain a fluorescent probe for the effective detection of doxycycline hydrochloride concentration. The specific method is as follows: A method for preparing carbon-doped quantum dot fluorescent probes includes using 3,4-difluorophenylboronic acid and ethylenediamine as precursors, and then treating the precursors by a one-step hydrothermal method to prepare boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs); wherein the addition ratio of 3,4-difluorophenylboronic acid to ethylenediamine is 0.18-0.22 g: 0.18-0.22 ml, and the one-step hydrothermal method involves mixing and stirring ultrapure water with the 3,4-difluorophenylboronic acid and ethylenediamine, and the addition ratio of ultrapure water to 3,4-difluorophenylboronic acid is 8.5-9.5 ml: 0.18-0.22 g.
[0006] Preferably, the temperature of the one-step hydrothermal method is 170-185℃, and the stirring time is 6.5-7.5h to obtain the reactants.
[0007] Preferably, the method further includes filtering the reactants obtained by the one-step hydrothermal method through a 0.22 μm filter membrane to obtain a liquid sample, and then cooling and drying to obtain a yellow BFN-CQDs solid powder.
[0008] The second objective of this application is to provide an application of a carbon-doped quantum dot fluorescent probe, including a carbon-doped quantum dot fluorescent probe prepared by the method described above, and its application in the quantitative detection of doxycycline hydrochloride concentration in a water sample.
[0009] Preferably, the quantitative detection is implemented using linear equation calculation, and the calculation method of the linear equation includes: step ① dissolving the BFN-CQDs in ultrapure water to obtain a BFN-CQDs stock solution; step ② diluting the BFN-CQDs stock solution to obtain a BFN-CQDs working solution; step ③ dissolving doxycycline hydrochloride powder in ultrapure water to obtain a doxycycline hydrochloride stock solution; and step ④ adding the BFN-CQDs working solution to ultrapure water at 4... Under 10 nm excitation, the fluorescence intensity F0 of BFN-CQDs at 510 nm was recorded. Doxycycline hydrochloride stock solution was added, and the fluorescence intensity F of the mixed system was tested. The Origin software was used to linearly fit the doxycycline hydrochloride concentration to (1-F) / F0, obtaining a linear relationship. In step ⑤, within the linear relationship range of 0.138 mmol / L-0.421 mmol / L, the linear equation obtained was: (1-F) / F0 = 2.32065c （DOX） -0.16669, R²=0.9965.
[0010] Preferably, in step ①, the concentration of BFN-CQDs in the BFN-CQDs stock solution is 10 mg / mL.
[0011] Preferably, in step ②, the concentration of BFN-CQDs in the solution is 1 mg / mL.
[0012] Preferably, in step ③, the concentration of doxycycline hydrochloride in the doxycycline hydrochloride stock solution is 0.01 mol / L.
[0013] Preferably, the doxycycline hydrochloride stock solution is prepared by using 0.4809... Xg of doxycycline hydrochloride powder dissolved in 100 It is obtained by fully dissolving in X mL of ultrapure water, where X is a constant greater than 0.
[0014] Preferably, in step ④, 500 μL of BFN-CQDs working solution is added to 2 mL of ultrapure water and mixed.
[0015] As can be seen from the above scheme, this application provides a method for preparing a carbon-doped quantum dot fluorescent probe and its application. The method for preparing the carbon-doped quantum dot fluorescent probe has the effect of preparing a carbon-doped quantum dot fluorescent probe that can be directly used to detect the content of doxycycline hydrochloride in water samples. Moreover, the preparation method is simple, and the detection is fast, efficient and quantitative. The carbon-doped quantum dot fluorescent probe prepared by this method has the effects of stable performance, strong anti-interference ability and high accuracy in detecting the content of doxycycline hydrochloride. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0017] Figure 1 The ultraviolet spectrum of BFN-CQDs prepared in Example 1 of this application; Figure 2 The fluorescence spectrum of BFN-CQDs prepared in Example 1 of this application is shown. Figure 3 This is a three-dimensional excitation wavelength-dependent plot of BFN-CQDs prepared in Example 1 of this application; Figure 4 This is a stability graph of BFN-CQDs prepared in Experimental Example 1 of this application based on solutions with different pH values; Figure 5 This is a graph showing the anti-interference test results of each drug on the detection of doxycycline hydrochloride in Experiment Example 2 of this application; Figure 6 This is a graph showing the change in fluorescence intensity of the mixed system in Example 1 of this application when doxycycline hydrochloride solution was added dropwise. Figure 7 This is a line graph showing the relationship between the concentration of doxycycline hydrochloride and the fluorescence intensity of BFN-CQDs in Example 1 of this application. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0019] The following will describe in detail the preparation method and application of a carbon-doped quantum dot fluorescent probe according to this application.
[0020] A method for preparing carbon-doped quantum dot fluorescent probes includes using 3,4-difluorophenylboronic acid and ethylenediamine as precursors, followed by a one-step hydrothermal treatment of the precursors to obtain boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs). The addition ratio of 3,4-difluorophenylboronic acid to ethylenediamine is 0.18-0.22 g:0.18-0.22 ml. The one-step hydrothermal method involves mixing and stirring ultrapure water with the 3,4-difluorophenylboronic acid and ethylenediamine, with the addition ratio of ultrapure water to 3,4-difluorophenylboronic acid being 8.5-9.5 ml:0.18-0.22 g.
[0021] It should be noted that the temperature of the one-step hydrothermal method is 170-185℃, and the stirring time is 6.5-7.5h to obtain the reactants. In order to achieve effective purification and material acquisition, the preparation method also includes filtering the reactants obtained by the one-step hydrothermal method through a 0.22μm filter membrane to obtain a liquid sample, and then cooling and drying to obtain a yellow BFN-CQDs solid powder.
[0022] An application of a carbon-doped quantum dot fluorescent probe includes preparing a carbon-doped quantum dot fluorescent probe using the method described above, and applying it to the quantitative detection of doxycycline hydrochloride concentration in a water sample.
[0023] It is worth mentioning that in order to obtain the detection data, a linear equation needs to be established for the correlation between BFN-CQDs and doxycycline hydrochloride, so that the final concentration value of doxycycline hydrochloride can be calculated based on the linear equation during the quantitative detection process.
[0024] In this embodiment, the method for calculating the linear equation includes: Step ① dissolving the BFN-CQDs in ultrapure water to obtain a BFN-CQDs stock solution; Step ② diluting the BFN-CQDs stock solution to obtain a BFN-CQDs working solution; Step ③ dissolving doxycycline hydrochloride powder in ultrapure water to obtain a doxycycline hydrochloride stock solution; Step ④ adding the BFN-CQDs working solution to ultrapure water, recording the fluorescence intensity F0 of BFN-CQDs at 510 nm under 410 nm excitation, adding the doxycycline hydrochloride stock solution, testing the fluorescence intensity F of the mixed system, and using Origin software to linearly fit the doxycycline hydrochloride concentration with (1-F) / F0 to obtain a linear relationship; Step ⑤ obtaining the linear equation (1-F) / F0 = 2.32065c within the linear relationship range of 0.138 mmol / L-0.421 mmol / L. （DOX） -0.16669, R²=0.9965.
[0025] The concentration of BFN-CQDs in the BFN-CQDs stock solution was 10 mg / mL. The concentration of BFN-CQDs in the BFN-CQDs working solution was 1 mg / mL. The concentration of doxycycline hydrochloride in the doxycycline hydrochloride stock solution was 0.01 mol / L. The doxycycline hydrochloride stock solution was prepared by using 0.4809... Xg of doxycycline hydrochloride powder dissolved in 100 The solution was obtained by fully dissolving the sample in X mL of ultrapure water, where X is a constant greater than 0. Before excitation, 500 μL of the BFN-CQDs working solution was added to 2 mL of ultrapure water and mixed before excitation at 410 nm.
[0026] Experimental Example 1 A method for preparing carbon-doped quantum dot fluorescent probes includes using 3,4-difluorophenylboronic acid and ethylenediamine as precursors, followed by a one-step hydrothermal treatment of the precursors to obtain boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs). The addition ratio of 3,4-difluorophenylboronic acid to ethylenediamine is 0.2 g:0.2 ml. The one-step hydrothermal method involves mixing and stirring ultrapure water with the 3,4-difluorophenylboronic acid and ethylenediamine, with an addition ratio of ultrapure water to 3,4-difluorophenylboronic acid of 9:0.2.
[0027] It should be noted that the temperature of the one-step hydrothermal method is 180℃, and the stirring time is 7h to obtain the reactants. In order to achieve effective purification and material acquisition, the preparation method also includes filtering the reactants obtained by the one-step hydrothermal method through a 0.22μm filter membrane to obtain a liquid sample, and then cooling and drying to obtain a yellow BFN-CQDs solid powder.
[0028] like Figure 1 , Figure 2 , Figure 3 As shown in the UV spectrum of the BFN-CQDs in Example 1 of this application, three distinct absorption peaks are observed at 266 nm, 242 nm, and 236.5 nm. The absorption at 200-300 nm is due to the π-π bond of the C=C double bond. This is caused by a transition. The optimal excitation and emission wavelengths for BFN-CQDs are 410 nm and 510 nm, respectively. Based on Figure 3 The three-dimensional excitation wavelength dependence plot of BFN-CQDs shows that when the excitation wavelength changes from 380nm to 460nm, the emission wavelength hardly changes, indicating that BFN-CQDs have excitation wavelength independence.
[0029] An application of a carbon-doped quantum dot fluorescent probe includes preparing a carbon-doped quantum dot fluorescent probe using the method described above, and applying it to the quantitative detection of doxycycline hydrochloride concentration in a water sample.
[0030] It is worth mentioning that in order to obtain the detection data, a linear equation needs to be established for the correlation between BFN-CQDs and doxycycline hydrochloride, so that the final concentration value of doxycycline hydrochloride can be calculated based on the linear equation during the quantitative detection process.
[0031] In this embodiment, the method for calculating the linear equation includes: Step ① dissolving the BFN-CQDs in ultrapure water to obtain a BFN-CQDs stock solution; Step ② diluting the BFN-CQDs stock solution to obtain a BFN-CQDs working solution; Step ③ dissolving doxycycline hydrochloride powder in ultrapure water to obtain a doxycycline hydrochloride stock solution; Step ④ adding the BFN-CQDs working solution to ultrapure water, recording the fluorescence intensity F0 of BFN-CQDs at 510 nm under 410 nm excitation, adding the doxycycline hydrochloride stock solution, testing the fluorescence intensity F of the mixed system, and using Origin software to linearly fit the doxycycline hydrochloride concentration with (1-F) / F0 to obtain a linear relationship; Step ⑤ obtaining the linear equation (1-F) / F0 = 2.32065c within the linear relationship range of 0.138 mmol / L-0.421 mmol / L. （DOX） -0.16669, R²=0.9965, as Figure 7 As shown.
[0032] The concentration of BFN-CQDs in the BFN-CQDs stock solution was 10 mg / mL. The concentration of BFN-CQDs in the BFN-CQDs working solution was 1 mg / mL. The concentration of doxycycline hydrochloride in the doxycycline hydrochloride stock solution was 0.01 mol / L. The doxycycline hydrochloride stock solution was prepared by using 0.4809... Xg of doxycycline hydrochloride powder dissolved in 100 The solution was obtained by fully dissolving the sample in X mL of ultrapure water, where X in Example 1 is 1. Before excitation, 500 μL of BFN-CQDs working solution was added to 2 mL of ultrapure water and mixed before excitation at 410 nm.
[0033] Experimental Example 2 A method for preparing carbon-doped quantum dot fluorescent probes includes using 3,4-difluorophenylboronic acid and ethylenediamine as precursors, followed by a one-step hydrothermal treatment of the precursors to obtain boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs). The addition ratio of 3,4-difluorophenylboronic acid to ethylenediamine is 0.18 g:0.18 ml. The one-step hydrothermal method involves mixing and stirring ultrapure water with the 3,4-difluorophenylboronic acid and ethylenediamine, with an addition ratio of ultrapure water to 3,4-difluorophenylboronic acid of 8.5 ml:0.18 g.
[0034] It should be noted that the temperature of the one-step hydrothermal method is 170℃, and the stirring time is 6.5-7.5h to obtain the reactants. In order to achieve effective purification and material acquisition, the preparation method also includes filtering the reactants obtained by the one-step hydrothermal method through a 0.22μm filter membrane to obtain a liquid sample, and then cooling and drying to obtain a yellow BFN-CQDs solid powder.
[0035] An application of a carbon-doped quantum dot fluorescent probe includes preparing a carbon-doped quantum dot fluorescent probe using the method described above, and applying it to the quantitative detection of doxycycline hydrochloride concentration in a water sample.
[0036] It is worth mentioning that in order to obtain the detection data, a linear equation needs to be established for the correlation between BFN-CQDs and doxycycline hydrochloride, so that the final concentration value of doxycycline hydrochloride can be calculated based on the linear equation during the quantitative detection process.
[0037] In this embodiment, the method for calculating the linear equation includes: step ① dissolving the BFN-CQDs in ultrapure water to obtain a BFN-CQDs stock solution; step ② diluting the BFN-CQDs stock solution to obtain a BFN-CQDs working solution; step ③ dissolving doxycycline hydrochloride powder in ultrapure water to obtain a doxycycline hydrochloride stock solution; step ④ adding the BFN-CQDs working solution to ultrapure water, recording the fluorescence intensity F0 of BFN-CQDs at 510 nm under 410 nm excitation, adding the doxycycline hydrochloride stock solution, testing the fluorescence intensity F of the mixed system, and using Origin software to linearly fit the doxycycline hydrochloride concentration with (1-F) / F0 to obtain a linear relationship.
[0038] The concentration of BFN-CQDs in the BFN-CQDs stock solution was 10 mg / mL. The concentration of BFN-CQDs in the BFN-CQDs working solution was 1 mg / mL. The concentration of doxycycline hydrochloride in the doxycycline hydrochloride stock solution was 0.01 mol / L. The doxycycline hydrochloride stock solution was prepared by using 0.4809... Xg of doxycycline hydrochloride powder dissolved in 100 The solution was obtained by fully dissolving the sample in X mL of ultrapure water, where X in Example 2 is 2. Before excitation, 500 μL of BFN-CQDs working solution was added to 2 mL of ultrapure water and mixed, followed by excitation at 410 nm.
[0039] Experiment Example 3 A method for preparing carbon-doped quantum dot fluorescent probes includes using 3,4-difluorophenylboronic acid and ethylenediamine as precursors, followed by a one-step hydrothermal treatment of the precursors to obtain boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs). The addition ratio of 3,4-difluorophenylboronic acid to ethylenediamine is 0.22 g:0.22 ml. The one-step hydrothermal method involves mixing and stirring ultrapure water with the 3,4-difluorophenylboronic acid and ethylenediamine, with an addition ratio of 9.5 ml:0.22 g.
[0040] It should be noted that the temperature of the one-step hydrothermal method is 185℃, and the stirring time is 7.5h to obtain the reactants. In order to achieve effective purification and material acquisition, the preparation method also includes filtering the reactants obtained by the one-step hydrothermal method through a 0.22μm filter membrane to obtain a liquid sample, and then cooling and drying to obtain a yellow BFN-CQDs solid powder.
[0041] An application of a carbon-doped quantum dot fluorescent probe includes preparing a carbon-doped quantum dot fluorescent probe using the method described above, and applying it to the quantitative detection of doxycycline hydrochloride concentration in a water sample.
[0042] It is worth mentioning that in order to obtain the detection data, a linear equation needs to be established for the correlation between BFN-CQDs and doxycycline hydrochloride, so that the final concentration value of doxycycline hydrochloride can be calculated based on the linear equation during the quantitative detection process.
[0043] In this embodiment, the method for calculating the linear equation includes: step ① dissolving the BFN-CQDs in ultrapure water to obtain a BFN-CQDs stock solution; step ② diluting the BFN-CQDs stock solution to obtain a BFN-CQDs working solution; step ③ dissolving doxycycline hydrochloride powder in ultrapure water to obtain a doxycycline hydrochloride stock solution; step ④ adding the BFN-CQDs working solution to ultrapure water, recording the fluorescence intensity F0 of BFN-CQDs at 510 nm under 410 nm excitation, adding the doxycycline hydrochloride stock solution, testing the fluorescence intensity F of the mixed system, and using Origin software to linearly fit the doxycycline hydrochloride concentration with (1-F) / F0 to obtain a linear relationship.
[0044] The concentration of BFN-CQDs in the BFN-CQDs stock solution was 10 mg / mL. The concentration of BFN-CQDs in the BFN-CQDs working solution was 1 mg / mL. The concentration of doxycycline hydrochloride in the doxycycline hydrochloride stock solution was 0.01 mol / L. The doxycycline hydrochloride stock solution was prepared by using 0.4809... Xg of doxycycline hydrochloride powder dissolved in 100 The solution was obtained by fully dissolving the sample in X mL of ultrapure water, where X in Example 3 is 4. Before excitation, 500 μL of BFN-CQDs working solution was added to 2 mL of ultrapure water and mixed, followed by excitation at 410 nm.
[0045] Experimental Example 1 Depend on Figure 4 As shown, the BFN-CQDs solution from Example 1 was added in 100 μL equivalent amounts to solutions with pH values of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13, respectively, and the fluorescence intensity F was measured at an excitation wavelength of 410 nm.
[0046] It can be seen that the fluorescence of BFN-CQDs remains stable in solutions with different pH values.
[0047] Experimental Example 2 The interference resistance experiment for the detection of doxycycline hydrochloride is performed as follows: Step 1: Add 100 μL of BFN-CQDs working solution to 2 mL of ultrapure water and measure its initial fluorescence intensity F0 at an excitation wavelength of 410 nm.
[0048] Step 2: Add 10 μL of 0.01 mol / L tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), amoxicillin (AMX), ampicillin (AMP), ceftriaxone sodium (CTR), ciprofloxacin (CIP), and enrofloxacin (ENR) to the solution from Step 1, and measure the fluorescence intensity of the mixed solution, which is recorded as F1. Step 3: Add 10 μL of 0.01 mol / L doxycycline hydrochloride to the solution obtained in Step 2, measure the fluorescence intensity, and record it as F2; like Figure 5 As shown, F1 / F0 yields a black bar chart, and F2 / F1 yields a gray bar chart, demonstrating that this detection method is not affected by other drugs and has good anti-interference capabilities.
[0049] Experiment Example 3 Testing procedure: Take tap water samples and water samples from a certain location for testing. In Experiment Example 3 of this application, the water sample from the certain location is the Beichuan River in Lüliang City, and use a 0.45μm filter membrane to remove suspended solids.
[0050] During the detection process, 2 mL of the water sample to be tested was first taken, and 500 μL of BFN-CQDs working solution was added. Doxycycline hydrochloride stock solution was then added to the sample at equivalent volumes of 0, 50, and 100 μL, corresponding to spiked concentrations of 0, 0.196, and 0.385 mmol / L, respectively. The change in fluorescence intensity of BFN-CQDs at 510 nm before and after sample addition was measured, and the doxycycline hydrochloride content in the sample was obtained by substituting the result into a linear equation. Three parallel experiments were performed for each sample, and the recovery rate and relative standard deviation (RSD) were calculated.
[0051] The results showed that no doxycycline hydrochloride residues were detected in either type of water sample. In three parallel experiments, the average recoveries at spike levels of 50 and 100 μL were 98.81% and 100.87%, respectively, with RSDs of 3.44% and 2.58%. This demonstrates that the established fluorescent probe exhibits good accuracy and precision for the detection of doxycycline hydrochloride in water samples.
[0052] In summary, this application provides a method for preparing a carbon-doped quantum dot fluorescent probe and its application. This method for preparing a carbon-doped quantum dot fluorescent probe has the effect of obtaining a carbon-doped quantum dot fluorescent probe that can be directly used to detect the content of doxycycline hydrochloride in water samples. Moreover, the preparation method is simple, and the detection is rapid, efficient, and quantitative. The carbon-doped quantum dot fluorescent probe prepared by this method has the effects of stable performance, strong anti-interference ability, and high accuracy in detecting the content of doxycycline hydrochloride.
[0053] The terms “first,” “second,” “third,” “fourth,” etc., used in this application (if applicable) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, or apparatus.
[0054] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.
[0055] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for preparing a carbon-doped quantum dot fluorescent probe, characterized in that: The method involves using 3,4-difluorophenylboronic acid and ethylenediamine as precursors, followed by a one-step hydrothermal treatment of the precursors to prepare boron, fluorine, and nitrogen co-doped carbon quantum dot fluorescent probes (BFN-CQDs). The ratio of 3,4-difluorophenylboronic acid to ethylenediamine is 0.18-0.22 g:0.18-0.22 ml. The one-step hydrothermal method involves mixing and stirring ultrapure water with the 3,4-difluorophenylboronic acid and ethylenediamine, with the ratio of ultrapure water to 3,4-difluorophenylboronic acid being 8.5-9.5 ml:0.18-0.22 g.
2. The method for preparing a carbon-doped quantum dot fluorescent probe according to claim 1, characterized in that: The one-step hydrothermal method involves a temperature of 170-185℃ and a stirring time of 6.5-7.5h to obtain the reactants.
3. The method for preparing a carbon-doped quantum dot fluorescent probe according to claim 2, characterized in that: It also includes filtering the reactants obtained by the one-step hydrothermal method through a 0.22 μm filter membrane to obtain a liquid sample, and then cooling and drying to obtain a yellow BFN-CQDs solid powder.
4. An application of a carbon-doped quantum dot fluorescent probe, characterized in that: This includes a carbon-doped quantum dot fluorescent probe prepared using the method described in any one of claims 1-3, and applied to the quantitative detection of doxycycline hydrochloride concentration in a water sample.
5. The application of the carbon-doped quantum dot fluorescent probe according to claim 4, characterized in that: The quantitative detection is implemented using linear equation calculation, and the calculation method of the linear equation includes: Step ① dissolving the BFN-CQDs in ultrapure water to obtain a BFN-CQDs stock solution; Step ② diluting the BFN-CQDs stock solution to obtain a BFN-CQDs working solution; Step ③ dissolving doxycycline hydrochloride powder in ultrapure water to obtain a doxycycline hydrochloride stock solution; Step ④ adding the BFN-CQDs working solution to ultrapure water, recording the fluorescence intensity F0 of BFN-CQDs at 510 nm under 410 nm excitation, adding the doxycycline hydrochloride stock solution, testing the fluorescence intensity F of the mixed system, and using Origin software to linearly fit the doxycycline hydrochloride concentration with (1-F) / F0 to obtain a linear relationship; Step ⑤ within the linear relationship range of 0.138 mmol / L-0.421 mmol / L, the linear equation obtained is: (1-F) / F0=2.32065c （DOX） -0.16669, R²=0.9965.
6. The method for preparing a carbon-doped quantum dot fluorescent probe according to claim 5, characterized in that: In step ①, the concentration of BFN-CQDs in the BFN-CQDs stock solution is 10 mg / mL.
7. The method for preparing a carbon-doped quantum dot fluorescent probe according to claim 5, characterized in that: In step ②, the concentration of BFN-CQDs in the solution is 1 mg / mL.
8. The method for preparing a carbon-doped quantum dot fluorescent probe according to claim 5, characterized in that: In step ③, the concentration of doxycycline hydrochloride in the doxycycline hydrochloride stock solution is 0.01 mol / L.
9. The method for preparing a carbon-doped quantum dot fluorescent probe according to claim 8, characterized in that: The doxycycline hydrochloride stock solution was prepared by using 0.4809 Xg of doxycycline hydrochloride powder dissolved in 100 It is obtained by fully dissolving in X mL of ultrapure water, where X is a constant greater than 0.
10. The method for preparing a carbon-doped quantum dot fluorescent probe according to claim 5, characterized in that: In step ④, take 500 μL of BFN-CQDs working solution and add it to 2 mL of ultrapure water and mix.