A fluorescent covalent organic framework material for antibiotic detection, preparation method and application thereof
By preparing three-dimensional covalent organic framework materials with planar interlaced structures, the problems of insufficient diversity of three-dimensional covalent organic framework structures and complex antibiotic detection were solved, and efficient and simple water quality antibiotic detection was achieved.
Patent Information
- Application Number
- CN202310689012.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-09
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2043-06-09
AI Technical Summary
The structural diversity of three-dimensional covalent organic frameworks in existing technologies is limited, their synthesis is difficult, and the antibiotic detection methods are complex and costly, lacking simple and efficient detection methods.
A three-dimensional covalent organic framework material with a planar interpenetrating structure was used to prepare a covalent organic framework material with fluorescent properties by reacting aldehyde and amino precursors under specific conditions. It was then applied to the fluorescence detection of nitrofuran antibiotics in aqueous phase.
It achieves high stability and low-cost antibiotic detection with low detection limit and high sensitivity, and is suitable for water quality monitoring.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of porous material preparation and organic pollutant detection technology in aqueous phase, and in particular to a fluorescent covalent organic framework material that can be used for antibiotic detection, a preparation method thereof and applications. Background Art
[0002] Three-dimensional (3D) covalent organic frameworks (COFs) are a class of crystalline organic porous materials, typically characterized by low density, high specific surface area, excellent thermal stability, and customizable functionalization. They are currently widely used in fields such as gas adsorption, separation, catalysis, sensing, optoelectronics, and energy storage. However, their limited structural diversity and the difficulty in synthesizing highly crystalline samples have hindered their development. Developing novel 3D COFs and exploring their synthesis strategies and preparation methods are of great importance. Framework chemistry suggests that constructing 3D COFs by interpenetrating two-dimensional planes is an important approach to enrich their structural diversity. 3D COFs with interpenetrating planes can, in principle, combine the advantages of 3D COFs—through pores, abundant exposed sites, and nanoscale hierarchical pores—with the properties of 2D COFs, such as conjugated planes and π-π stacking pillars. Therefore, 3D COFs with interpenetrating planes hold great promise for development. However, only one relevant paper has been reported, primarily due to a lack of synthetic strategies and theoretical guidance.
[0003] With increasing concern for public health and water quality, the demand for detecting and removing pollutants in wastewater is growing. Antibiotics, widely used to treat bacterial infections in humans and animals, are a significant class of organic pollutants in water. The overuse of antibiotics has resulted in significant amounts of antibiotic residues, with various antibiotics detected in surface water, groundwater, and drinking water. However, current detection methods primarily rely on techniques such as chromatography and mass spectrometry, which are complex to operate and have high instrument costs. The development of new, simple, and efficient detection methods holds significant application value and scientific significance. Fluorescence detection is an effective method for detecting low-concentration analytes. The application of covalent organic frameworks (COFs) for antibiotic detection offers the following advantages: First, they are pure organic materials with strong designability. Fluorescence properties can be manipulated through molecular building block design, enabling the construction of COFs with excellent fluorescence properties. Second, their porosity allows for the enrichment of analytes within their pores, amplifying the fluorescence signal and enabling the construction of COFs with low detection limits and high sensitivity for the analytes. Finally, the covalent bond formation imparts high stability, enabling them to be recycled in practical applications. Summary of the Invention
[0004] One of the objectives of the present invention is to provide a fluorescent covalent organic framework material that can be used for antibiotic detection. The material has high stability, can efficiently detect nitrofuran antibiotics in water through an electron transfer mechanism, and is reusable.
[0005] A second object of the present invention is to provide a method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection, which has a simple preparation process and is easy to adjust.
[0006] A third object of the present invention is to provide an application of a fluorescent covalent organic framework material that can be used for antibiotic detection.
[0007] The solution adopted by the present invention to achieve one of the purposes is: a fluorescent covalent organic framework material that can be used for antibiotic detection, the molecular structure of the covalent organic framework material is The covalent organic framework material is a novel SQL planar interlaced topological structure.
[0008] The solution adopted by the present invention to achieve the second purpose is: a method for preparing the fluorescent covalent organic framework material that can be used for antibiotic detection, wherein an aldehyde precursor and an amino precursor are dispersed in a solvent, a catalyst is added, and the resulting mixed system is reacted at 80-160°C under vacuum or an inert atmosphere. After the reaction is completed, a yellow solid powder is obtained, which is purified and dried to obtain the covalent organic framework.
[0009] Preferably, the amino precursor is The aldehyde precursor is
[0010] Preferably, the solvent is a good solvent, or a solution formed by mixing a good solvent and a poor solvent in any volume ratio: the good solvent is at least one of toluene, chloroform, o-dichlorobenzene, and mesitylene; the poor solvent is at least one of n-hexane, n-butanol, tert-butanol, and isopropanol.
[0011] Preferably, the catalyst is acetic acid.
[0012] Preferably, the molar ratio of the amino precursor, aldehyde precursor and catalyst is 1:1:30-150; the concentration of the amino precursor in the mixed system is 0.01-0.1 mol / L, and the concentration of the catalyst is 1-17 mol / L.
[0013] Preferably, the purification process is to perform Soxhlet extraction on the solid product using at least one of tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, and dimethyl sulfoxide, and then perform Soxhlet extraction on the solid using dichloromethane.
[0014] Preferably, the preparation method of the precursor molecule is as follows: the preparation method of the aldehyde precursor or amino precursor is as follows: the halogenated molecule, phenylboronic acid reagent, catalyst and alkaline agent are dispersed in a solvent, and then reacted at 80-120°C under an inert atmosphere. After the reaction is completed, the solvent is removed and purified to obtain a solid product, namely the aldehyde precursor or amino precursor.
[0015] Preferably, the halogenated molecule is N9,N9,N 10 ,N 10 -Tetrakis(4-bromophenyl)anthracene-9,10-diamine or N9,N9,N 10 ,N 10 -tetrakis(4-iodophenyl)anthracene-9,10-diamine, the phenylboronic acid reagent is at least one of 4-formaldehyde phenylboronic acid, 4-formaldehyde phenylboronic acid pinacol ester, 4-aminophenylboronic acid or 4-aminophenylboronic acid pinacol ester, the catalyst is tetrakistriphenylphosphine palladium, the alkali agent is at least one of cesium carbonate, potassium carbonate, sodium carbonate and potassium phosphate, the solvent is at least one of toluene, 1,4-dioxane and N,N-dimethylformamide, and the molar ratio of the halogenated molecule, phenylboronic acid reagent, tetrakistriphenylphosphine palladium and alkali agent is 50:200-500:5:200-500.
[0016] The solution adopted by the present invention to achieve the third purpose is: an application of the fluorescent covalent organic framework material that can be used for antibiotic detection, and applying the covalent organic framework to the fluorescence detection of nitrofuran antibiotics in an aqueous phase.
[0017] The present invention has the following advantages and beneficial effects:
[0018] 1. The covalent organic framework material of the present invention has a rare three-dimensional framework structure formed by the interlocking of two-dimensional SQL planes, and has fluorescent properties and high stability. It can efficiently detect nitrofuran antibiotics in water through an electron transfer mechanism and is reusable.
[0019] 2. The preparation method of the present invention synthesizes a novel fluorescent covalent organic framework by designing and synthesizing a covalent organic framework with a planar interpenetrating structure and exhibiting fluorescent properties. The preparation method is easy to operate, environmentally friendly, low-cost, and amenable to industrial production.
[0020] 3. The covalent organic framework prepared by the present invention has high stability and, combined with the fluorescence sensing mechanism, can efficiently detect nitrofuran antibiotic pollutants in the aqueous phase. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 The X-ray powder diffraction pattern of the covalent organic framework prepared in the present invention;
[0022] Figure 2(a) shows the PXRD pattern and SEM morphology of 3D-An-COF, and (b) shows the three-dimensional reciprocal lattice of 3D-An-COF.
[0023] Figure 3 Schematic diagram of the covalent organic framework prepared by the present invention, wherein Figure 3 a is a structure where two SQL topology networks are almost vertically interlaced. Figure 3 b is a frame with a two-dimensional interlaced structure. Figure 3 c is the one-dimensional pore structure of the framework;
[0024] Figure 4 Solid fluorescence and antibiotic detection results of the covalent organic framework prepared by the present invention, wherein Figure 4 a is the solid fluorescent material of the covalent organic framework prepared by the present invention, Figure 4 bd is the fluorescence detection result of nitrofuran antibiotics in the aqueous phase. DETAILED DESCRIPTION
[0025] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.
[0026] Example 1
[0027] PADA (aldehyde precursor) (8.8 mg, 0.01 mmol) and PADC (amino precursor) (9.3 mg, 0.01 mmol) were dispersed in a mixed solution of toluene and isopropanol (0.9 ml / 0.15 ml), and then 0.105 mL of 15 mol L -1 Acetic acid solution, and finally placed it in a 140 ° C oven to react for 72 hours. After the reaction is completed, a yellow solid powder is obtained. The solid is Soxhlet extracted with tetrahydrofuran and dichloromethane in sequence, and finally the solid is placed in a vacuum environment and heated to dry for use. The covalent organic framework material is synthesized as follows; the PADA unit is The PADC primitive is
[0028]
[0029] Figure 1 This is the X-ray powder diffraction pattern of the covalent organic framework prepared in this example. It can be seen from the figure that the covalent organic framework exhibits a series of diffraction peaks in the range of 2-40°, indicating that it has a long-range ordered crystalline structure.
[0030] Figure 2The PXRD patterns of 3D-An-COF are shown. Curve 1 in Figure a represents the experimental XRD pattern, the refined XRD pattern, the difference between the experimental and refined patterns, the Bragg position of the crystal structure, and the SEM morphology of the crystal. b is the three-dimensional reciprocal lattice of 3D-An-COF. It can be seen that the reflection conditions indicate that the possible space group is Pccn. According to the standard of I / σ>1, the resolution is limited to It is worth noting that, finally, the Rietveld refinement gives the lattice parameters Among them, Rwp=9.58% and Rp=6.43%.
[0031] Figure 3 The covalent organic framework prepared by the present invention is shown as a three-dimensional structure, wherein Figure a is a nearly vertical interlaced structure of two SQL topological networks, Figure b is a framework with a two-dimensional planar interlaced structure, and Figure c is a one-dimensional channel structure of the framework.
[0032] Table 1 shows the unit cell parameters and atomic coordinates of 3D-An-COF obtained by Rietveld refinement.
[0033]
[0034]
[0035] Example 2
[0036] The synthesis of PADA in Example 1 is as follows:
[0037]
[0038] Compound 1 (2.00 g, 2.43 mmol), 4-aminophenylboronic acid pinacol ester (2.55 g, 11.65 mmol), tetrakistriphenylphosphine palladium (0.15 g, 0.125 mmol), and potassium carbonate (2.69 g, 19.44 mmol) were placed in a round-bottom flask, and then dioxane solvent (80 mL) was added to disperse it. Then, the mixture was heated at 90 ° C under nitrogen protection for 3 days. After the reaction was completed, water was added to precipitate the solid, which was filtered and purified by column chromatography to obtain a yellow solid product. 1 H NMR (400M, DMSO-d6, ppm): δ = 8.19 (m, 4H), 7.51 (m, 4H), 7.43 (d, J = 8.8Hz, 8H), 7 .28(d,J=8.6Hz,8H), 7.06(d,J=8.7Hz,8H), 6.60(d,J=8.5Hz,8H), 5.14(s,8H).
[0039] The synthesis of PADC in Example 1 is as follows:
[0040]
[0041] Compound 1 (3.00 g, 3.64 mmol), compound 2 (6.90 g, 21.85 mmol), tetrakistriphenylphosphine palladium (0.21 g, 0.18 mmol), and potassium carbonate (4.02 g, 29.12 mmol) were placed in a round-bottom flask. A mixture of toluene and water (120 mL / 40 mL) was added to disperse the mixture. The mixture was then heated at 100°C under nitrogen for 3 days. After completion of the reaction, the solvent was removed by rotary evaporation and purified by column chromatography to obtain the yellow solid product 3. The product was characterized by nuclear magnetic resonance. 1 H NMR (400MHz, CDCl3, ppm): δ = 8.27 (m, 4H), 7.57 (m, 16H), 7.49 (d, J = 8.7Hz, 8H), 7.44 (m, 4H), 7.24 (d, J =8.7Hz, 8H), 5.44 (s, 4H), 3.81 (d, J = 11.3Hz, 8H), 3.69 (d, J = 10.9Hz, 8H), 1.33 (s, 12H), 0.83 (s, 12H). .
[0042] Trifluoroacetic acid (5 mL) was added to a solution of compound 3 (2.50 g, 1.96 mmol) in dichloromethane (100 mL) and stirred at room temperature overnight. Saturated sodium carbonate solution was then added to the reaction mixture to quench the excess acid. The mixture was then extracted with dichloromethane, washed with brine, and the organic phase was dried over anhydrous sodium sulfate. The solvent was then removed under vacuum to yield the product, PADC, as a yellow solid. 1H NMR (400 MHz, CDCl3, ppm): δ = 10.03 (s, 4H), 8.25 (m, 4H), 7.92 (d, J = 8.3 Hz, 8H), 7.71 (d, J = 8.3 Hz, 8H), 7.56 (d, J = 8.8 Hz, 8H), 7.47 (m, 4H), 7.28 (d, J = 8.8 Hz, 8H).
[0043] Example 3
[0044] The organic covalent framework material prepared in Example 1 was used for the detection of aqueous nitrofuran antibiotics:
[0045] The covalent organic framework was used as a fluorescent sensor to detect antibiotics in aqueous solution: the activated covalent organic framework material (the activation process is: the solid product obtained during the purification process (using at least one of tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, and dimethyl sulfoxide to Soxhlet extraction, and finally Soxhlet extraction of the solid with dichloromethane) was dried under vacuum at 100°C for 6 hours.) was dispersed in ultrapure water and sonicated for several minutes to keep the solid stably and evenly suspended in the aqueous solution. The antibiotic aqueous solution (1mM) was added dropwise to the covalent organic framework suspension (1mg / 3mL), 20μL each time, and the fluorescence intensity was recorded.
[0046] Figure 4 Figures 2 and 3 show the solid fluorescence and antibiotic detection results. Figure a shows the solid fluorescence of the covalent organic framework prepared by the present invention, and Figures b and d show the fluorescence detection results of nitrofuran antibiotics (nitrofurazone, nitrofurantoin, and nitrofurantoin) in the aqueous phase. As can be seen from the figure, when the antibiotics are added to the aqueous suspension of the covalent organic framework material, the fluorescence intensity of the system rapidly weakens, indicating that the covalent organic framework material has a fluorescence quenching response effect on the antibiotics and can be used for the detection of nitrofuran antibiotics in the aqueous phase.
[0047] The above description is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principles of the present invention. These improvements and changes are also considered to be within the scope of protection of the present invention.
Claims
1. A fluorescent covalent organic framework material that can be used for antibiotic detection, characterized by: The molecular structure of the covalent organic framework material is The covalent organic framework material is a novel SQL planar interlaced topological structure.
2. A method for preparing a fluorescent covalent organic framework material for antibiotic detection according to claim 1, characterized in that: The aldehyde precursor and the amino precursor are dispersed in a solvent, and a catalyst is added. The resulting mixed system is reacted at 80-160° C. under vacuum or inert atmosphere. After the reaction is completed, a yellow solid powder is obtained, which is purified and dried to obtain the covalent organic framework.
3. The method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection according to claim 2, characterized in that: The amino precursor is The aldehyde precursor is 4. The method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection according to claim 2, characterized in that: The solvent is a good solvent, or a solution formed by mixing a good solvent and a poor solvent in any volume ratio: the good solvent is at least one of toluene, chloroform, o-dichlorobenzene, and mesitylene; the poor solvent is at least one of n-hexane, n-butanol, tert-butanol, and isopropanol.
5. The method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection according to claim 2, characterized in that: The catalyst is acetic acid.
6. The method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection according to claim 2, characterized in that: The molar ratio of the amino precursor, the aldehyde precursor and the catalyst is 1:1:30-150; the concentration of the amino precursor in the mixed system is 0.01-0.1 mol / L, and the concentration of the catalyst is 1-17 mol / L.
7. The method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection according to claim 2, characterized in that: The purification process comprises the following steps: performing Soxhlet extraction on the solid product using at least one of tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide and dimethyl sulfoxide, and then performing Soxhlet extraction on the solid product using dichloromethane.
8. The method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection according to claim 2, characterized in that: The preparation method of the precursor molecule is as follows: the preparation method of the aldehyde precursor or amino precursor is as follows: the halogenated molecule, phenylboronic acid reagent, catalyst and alkaline agent are dispersed in a solvent, and then reacted at 80-120°C under an inert atmosphere. After the reaction is completed, the solvent is removed and purified to obtain a solid product, namely the aldehyde precursor or amino precursor.
9. The method for preparing a fluorescent covalent organic framework material that can be used for antibiotic detection according to claim 8, characterized in that: The halogenated molecule is N9,N9,N 10 ,N 10 -Tetrakis(4-bromophenyl)anthracene-9,10-diamine or N9,N9,N 10 ,N 10 -tetrakis(4-iodophenyl)anthracene-9,10-diamine, the phenylboronic acid reagent is at least one of 4-formaldehyde phenylboronic acid, 4-formaldehyde phenylboronic acid pinacol ester, 4-aminophenylboronic acid or 4-aminophenylboronic acid pinacol ester, the catalyst is tetrakistriphenylphosphine palladium, the alkali agent is at least one of cesium carbonate, potassium carbonate, sodium carbonate and potassium phosphate, the solvent is at least one of toluene, 1,4-dioxane and N,N-dimethylformamide, and the molar ratio of the halogenated molecule, phenylboronic acid reagent, tetrakistriphenylphosphine palladium and alkali agent is 50:200-500:5:200-500.
10. A use of the fluorescent covalent organic framework material for antibiotic detection according to claim 1 or the fluorescent covalent organic framework material for antibiotic detection prepared by the preparation method of any one of claims 2 to 9, characterized in that: The covalent organic framework was applied to the fluorescence detection of nitrofuran antibiotics in aqueous phase.