Fluorescent probe for detecting formaldehyde as well as preparation method and application of fluorescent probe
By developing a fluorescent probe based on the 2-(2-hydroxyphenyl)phenidimidazole structure, using 2-Aza-Cope rearrangement reaction to detect formaldehyde, the problems of complex operation, selectivity and insufficient sensitivity of detection in the prior art are solved, and high sensitivity and selectivity detection are achieved.
Patent Information
- Application Number
- CN202510085351.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-05-02
AI Technical Summary
The prior art is complex in the detection of formaldehyde, requires special instruments and equipment, and still needs to be improved in terms of selectivity and sensitivity.
A fluorescent probe based on the 2-(2-hydroxyphenyl)phenidimidazole structure was developed, and a fluorescent probe was used as a formaldehyde recognition group to form imine through 2-Aza-Cope rearrangement, which then self-decomposes and hydrolysis, and finally produces a highly fluorescent aldehyde product, thereby realizing the detection of formaldehyde.
It realizes high sensitivity and selective detection of formaldehyde, and has the characteristics of simple operation, easy synthesis and short response time.
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Figure CN119912395A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of organic chemistry and biological detection technology, and more particularly to a fluorescent probe for detecting formaldehyde and a preparation method and application thereof. Background Art
[0002] Formaldehyde (FA), with the molecular formula HCHO, is a colorless gas with a pungent odor and is easily soluble in water. A 35% to 40% formaldehyde aqueous solution is commonly known as formalin, which has antiseptic and bactericidal properties. As an active carbonyl substance, formaldehyde has active chemical properties and is recognized by humans as a natural poison and carcinogen. Formaldehyde is irritating to the skin and mucous membranes. Direct contact of the skin with formaldehyde can cause allergic dermatitis, pigmentation, and necrosis. Inhalation of high concentrations of formaldehyde can induce bronchial asthma. High concentrations of formaldehyde are also a genotoxic substance. Therefore, it is very necessary to achieve high-sensitivity and high-selectivity real-time detection of formaldehyde in the environment and biological systems.
[0003] At present, the common methods for detecting formaldehyde mainly include spectrophotometry, chromatography, electrochemical method, sensor method, radioactive test method, etc. However, the above methods often require special instruments and equipment and are complicated to operate, and their selectivity and sensitivity still need to be improved. Fluorescent probes have the advantages of real-time, high sensitivity and selectivity, low physiological toxicity and strong anti-interference, and have great advantages and development prospects in the detection of formaldehyde. Therefore, the use of fluorescent probes for efficient detection of formaldehyde has received widespread attention and research.
[0004] Therefore, how to develop a simple, rapid and highly sensitive fluorescent probe for detecting formaldehyde is an urgent problem to be solved by those skilled in the art. Summary of the invention
[0005] In view of this, an object of the present invention is to provide a fluorescent probe for detecting formaldehyde and a preparation method and application thereof, so as to solve the deficiencies in the prior art.
[0006] In order to achieve the above object, the present invention adopts the following technical solution:
[0007] A fluorescent probe for detecting formaldehyde, the molecular formula is: C 32 H 25 N5O5, the structural formula is:
[0008]
[0009] A method for preparing the fluorescent probe for detecting formaldehyde comprises the following steps:
[0010] (1) dissolving allyl dibutoxy borane in an ammonia methanol solution, and stirring under a nitrogen atmosphere at room temperature to obtain a mixed solution;
[0011] (2) dissolving 3-hydroxy-4-(1-hydrogen-phenanthro[9,10-d]imidazol-2-yl)benzaldehyde in an ammonia methanol solution, adding water, and then adding the mixture to react at room temperature. After the reaction is completed, the solvent is removed under reduced pressure, and the crude product is separated and purified by silica gel chromatography to obtain an intermediate compound;
[0012] (3) The intermediate compound is dissolved in tetrahydrofuran under a nitrogen atmosphere and an ice bath, and then 3,5-dinitrobenzaldehyde, sodium cyanoborohydride and acetic acid are added and stirred at room temperature for reaction. After the reaction is completed, the solvent is removed under reduced pressure, and the crude product is separated and purified by a silica gel chromatography column to obtain a fluorescent probe for detecting formaldehyde.
[0013] The synthetic route of the fluorescent probe of the present invention is:
[0014]
[0015] Furthermore, in the above step (1), the concentration of the ammonia methanol solution is 7 mol / L; and the molar ratio of allyl dibutoxy borane to the ammonia methanol solution is (1-2):(4-10).
[0016] Furthermore, in the above step (1), the stirring time is 15 minutes.
[0017] Furthermore, in the above step (2), the concentration of the ammonia methanol solution is 7 mol / L; the molar ratio of 3-hydroxy-4-(1-hydrogen-phenanthro[9,10-d]imidazol-2-yl)benzaldehyde, ammonia methanol solution and water is 1:(4-15):(10-15).
[0018] Furthermore, in the above step (2), the reaction time is 24 hours.
[0019] Furthermore, in the above step (2), the developing solvent of the silica gel chromatography column is dichloromethane:methanol=30:1 (volume ratio).
[0020] Furthermore, in the above step (3), the molar ratio of the intermediate compound, 3,5-dinitrobenzaldehyde, sodium cyanoborohydride and acetic acid is 1:(2-10):(5-10):(5-20).
[0021] Furthermore, in the above step (3), the stirring reaction time is 12-24 hours, preferably 24 hours.
[0022] Furthermore, in the above step (3), the developing solvent of the silica gel chromatography column is dichloromethane:methanol=30:1 (volume ratio).
[0023] The present invention also seeks to protect the use of the fluorescent probe or the fluorescent probe prepared by the preparation method in detecting formaldehyde.
[0024] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:
[0025] The fluorescent probe of the present invention is based on the structure of 2-(2-hydroxyphenyl)phenanthroimidazole, uses homoallylamine as a formaldehyde recognition group, has no fluorescence itself, can form imine through 2-Aza-Cope rearrangement when reacting with formaldehyde, and then undergoes self-decomposition and hydrolysis to finally generate an aldehyde product with strong fluorescence, thereby realizing the detection of formaldehyde. The probe shows good selectivity and high sensitivity to formaldehyde, and has the characteristics of simple structure, easy synthesis, short response time, etc. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 is the intermediate compound obtained in step (2) of Example 2 1 H NMR spectrum (500 MHz, CDCl3);
[0027] Figure 2 is the intermediate compound obtained in step (2) of Example 2 13 C NMR spectrum (125 MHz, CDCl3);
[0028] Figure 3 The fluorescent probe prepared in step (3) of Example 2 1 H NMR spectrum (500 MHz, CDCl3);
[0029] Figure 4 The fluorescent probe prepared in step (3) of Example 2 13 C NMR spectrum (125 MHz, CDCl3);
[0030] Figure 5 The graph is a graph showing the fluorescence change relationship between the fluorescent probe prepared in step (3) of Example 2 and reaction solutions of different concentrations of formaldehyde. DETAILED DESCRIPTION
[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0032] Example 1
[0033] Fluorescent probe for detecting formaldehyde, molecular formula: C 32 H25 N5O5, the structural formula is:
[0034]
[0035] Example 2
[0036] The method for preparing the fluorescent probe for detecting formaldehyde in Example 1 specifically comprises the following steps:
[0037] (1) Allyldibutoxyborane (1.2 g, 6 mmol, 2 equiv) was dissolved in 7 mol / L ammonia methanol solution (4.3 mL, 10 equiv), and stirred at room temperature under nitrogen atmosphere for 15 min to obtain a mixed solution;
[0038] (2) 3-Hydroxy-4-(1-hydrogen-phenanthro[9,10-d]imidazol-2-yl)benzaldehyde (1 g, 3 mmol, 1 equiv) was dissolved in ammonia methanol solution (2.1 mL, 5 equiv), water (810 mg, 45 mmol, 15 equiv) was added, and then added to the mixture, and reacted at room temperature for 24 h. After the reaction, the solvent was removed under reduced pressure, and the crude product was separated and purified by silica gel chromatography with a developing solvent of dichloromethane:methanol = 30:1 to obtain an intermediate compound;
[0039] (3) Under nitrogen atmosphere and ice bath, the intermediate compound (1 g, 2.64 mmol, 1 equiv) was dissolved in tetrahydrofuran (60 mL), and then 3,5-dinitrobenzaldehyde (1.03 g, 5.28 mmol, 2 equiv), sodium cyanoborohydride (831.6 mg, 13.2 mmol, 5 equiv) and acetic acid (792 mg, 13.2 mmol, 5 equiv) were added. The ice bath was removed and the mixture was stirred at room temperature for 24 h. After the reaction was completed, the solvent was removed under reduced pressure and the crude product was separated and purified by silica gel chromatography to obtain a fluorescent probe for detecting formaldehyde.
[0040] Example 3
[0041] The method for preparing the fluorescent probe for detecting formaldehyde in Example 1 specifically comprises the following steps:
[0042] (1) Allyldibutoxyborane (1.2 g, 6 mmol, 2 equiv) was dissolved in 7 mol / L ammonia methanol solution (4.3 mL, 10 equiv), and stirred at room temperature under nitrogen atmosphere for 15 min to obtain a mixed solution;
[0043] (2) 3-Hydroxy-4-(1-hydrogen-phenanthro[9,10-d]imidazol-2-yl)benzaldehyde (1 g, 3 mmol, 1 equiv) was dissolved in ammonia methanol solution (2.1 mL, 5 equiv), water (810 mg, 45 mmol, 15 equiv) was added, and then added to the mixture, and reacted at room temperature for 24 h. After the reaction, the solvent was removed under reduced pressure, and the crude product was separated and purified by silica gel chromatography with a developing solvent of dichloromethane:methanol = 30:1 to obtain an intermediate compound;
[0044] (3) Under nitrogen atmosphere and ice bath, the intermediate compound (1 g, 2.64 mmol, 1 equiv) was dissolved in tetrahydrofuran (60 mL), and then 3,5-dinitrobenzaldehyde (1.03 g, 5.28 mmol, 2 equiv), sodium cyanoborohydride (831.6 mg, 13.2 mmol, 5 equiv) and acetic acid (792 mg, 13.2 mmol, 5 equiv) were added. The ice bath was removed and the reaction was stirred at room temperature for 18 h. After the reaction was completed, the solvent was removed under reduced pressure and the crude product was separated and purified by silica gel chromatography to obtain a fluorescent probe for detecting formaldehyde.
[0045] Example 4
[0046] The method for preparing the fluorescent probe for detecting formaldehyde in Example 1 specifically comprises the following steps:
[0047] (1) Allyldibutoxyborane (1.2 g, 6 mmol, 2 equiv) was dissolved in 7 mol / L ammonia methanol solution (4.3 mL, 10 equiv), and stirred at room temperature under nitrogen atmosphere for 15 min to obtain a mixed solution;
[0048] (2) 3-Hydroxy-4-(1-hydrogen-phenanthro[9,10-d]imidazol-2-yl)benzaldehyde (1 g, 3 mmol, 1 equiv) was dissolved in ammonia methanol solution (2.1 mL, 5 equiv), water (810 mg, 45 mmol, 15 equiv) was added, and then added to the mixture, and reacted at room temperature for 24 h. After the reaction, the solvent was removed under reduced pressure, and the crude product was separated and purified by silica gel chromatography with a developing solvent of dichloromethane:methanol = 30:1 to obtain an intermediate compound;
[0049] (3) Under nitrogen atmosphere and ice bath, the intermediate compound (1 g, 2.64 mmol, 1 equiv) was dissolved in tetrahydrofuran (60 mL), and then 3,5-dinitrobenzaldehyde (1.03 g, 5.28 mmol, 2 equiv), sodium cyanoborohydride (831.6 mg, 13.2 mmol, 5 equiv) and acetic acid (792 mg, 13.2 mmol, 5 equiv) were added. The ice bath was removed and the reaction was stirred at room temperature for 12 h. After the reaction was completed, the solvent was removed under reduced pressure. The crude product was separated and purified by silica gel chromatography to obtain a fluorescent probe for detecting formaldehyde.
[0050] Performance Testing
[0051] 1. The intermediate compound prepared in step (2) of Example 2 and the fluorescent probe prepared in step (3) of Example 2 were weighed and their yields were calculated. The results are shown in Table 1.
[0052] Table 1 The quality and yield of each product
[0053] product Mass / g Yield / % Intermediate Compounds 1.05 92 Fluorescent probes 4.8 65
[0054] As shown in Table 1, the final yield of the fluorescent probe prepared by this method is relatively good, which is 65%.
[0055] 2. Take the intermediate compound prepared in step (2) of Example 2 and the fluorescent probe prepared in step (3) of Example 2, and test them respectively. 1 H NMR spectra and 13 C NMR spectrum, the results are as follows Figure 1-4 shown.
[0056] Depend on Figure 1 It can be seen that 1 H NMR (500MHz, CDCl3) δ8.66-8.60 (m, 1H), 8.25-8.17 (m, 2H), 7.86-7.77 (m, 2H), 7.68 -7.53 (m, 4H), 7.18 (ddd, J=8.4, 2.0, 0.9Hz, 1H), 6.61 (dd, J=2.1, 1.0Hz, 1H), 5.83-5 .70 (m, 1H), 5.08 (dt, J=13.9, 1.0Hz, 2H), 4.11 (dtd, J=6.1, 5.0, 3.8Hz, 1H), 3.02 (d d, J=7.3, 5.1Hz, 1H), 2.74 (dd, J=7.3, 4.9Hz, 1H), 2.50 (ddt, J=7.0, 3.7, 0.9Hz, 2H).
[0057] Depend on Figure 2 It can be seen that 13C NMR (125MHz, CDCl3) δ154.99, 153.38, 144.21, 134.52, 133.42, 131.09, 130.59, 129.91, 128.76, 127.94, 127.38, 127.29, 126.93, 124.15, 124.02, 124.01, 123.75, 123.40, 122.23, 118.06, 117.92, 115.82, 111.05, 55.09, 40.85.
[0058] Depend on Figure 3 It can be seen that 1 H NMR (500MHz, CDCl3) δ8.93 (t, J=2.2Hz, 1H), 8.68 (dd, J=7.5, 1.2Hz, 1H), 8.49 (dt, J=2.2, 1.0Hz, 2H), 8.29-8.20 (m, 2H ), 7.76-7.67 (m, 1H), 7.65 (td, J=7.7, 1.3Hz, 1H), 7.63-7.54 (m, 3H), 7.48 (d, J=8.4Hz, 1H), 7.13 (ddd, J=8.4, 2.0, 1.1 Hz, 1H), 7.06 (dd, J=1.9, 1.0Hz, 1H), 5.89-5.76 (m, 1H), 5.09 (dt, J=13.8, 1.0Hz, 2H), 4.16-4.04 (m, 2H), 3.92-3.84 (m , 1H), 2.58 (dddt, J=14.6, 6.9, 4.8, 1.0Hz, 1H), 2.47 (dddt, J=14.6, 7.0, 4.8, 0.9Hz, 1H), 2.34 (dt, J=7.3, 5.7Hz, 1H).
[0059] Depend on Figure 4 It can be seen that 13 C NMR (125MHz, CDCl3) δ154.79, 154.67, 149.24, 144.01, 143.28, 133.51, 133.29, 130.89, 130.12, 129.86, 129.25, 128.78, 128.41, 127 .33, 126.60, 126.40, 124.07, 124.03, 123.75, 123.70, 123.54, 122.05, 120.21, 118.26, 117.57, 115.61, 110.93, 61.59, 50.34, 39.98.
[0060] 3. Dissolve the fluorescent probe obtained in step (3) of Example 2 in methanol to prepare a probe mother solution with a concentration of 10mM. Add a formaldehyde solution with a mass fraction of 37% to distilled water to prepare a formaldehyde mother solution with a formaldehyde concentration of 20mM. Prepare 500mL of spectral solution of PBS buffer (0.01mM, pH=7.4) and distribute it evenly at 5mL per test tube. Add 50μL of probe mother solution to each test tube, and then add formaldehyde of different concentrations (0, 0.3, 0.67, 1.35, 2.0, 3, 4, 5, 6, 8, 10mM) respectively. After reacting for 30 minutes, use a molecular fluorescence spectrometer to measure the relationship between the fluorescence changes of the probe and the reaction solutions of different concentrations of formaldehyde. The results are as follows: Figure 5 shown.
[0061] Depend on Figure 5 It can be seen that with the increase of formaldehyde concentration, the fluorescent probe produces a new emission band at 552nm and its fluorescence peak gradually increases, indicating that the fluorescent probe is effective in detecting formaldehyde.
[0062] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A fluorescent probe for detecting formaldehyde, characterized in that: The molecular formula is: C 32 H 25 N5O5, the structural formula is:
2. A method for preparing a fluorescent probe for detecting formaldehyde as claimed in claim 1, characterized in that: The specific steps include: (1) dissolving allyl dibutoxy borane in an ammonia methanol solution, and stirring under a nitrogen atmosphere at room temperature to obtain a mixed solution; (2) dissolving 3-hydroxy-4-(1-hydrogen-phenanthro[9,10-d]imidazol-2-yl)benzaldehyde in an ammonia methanol solution, adding water, and then adding the mixture to react at room temperature. After the reaction is completed, the solvent is removed under reduced pressure, and the crude product is separated and purified by silica gel chromatography to obtain an intermediate compound; (3) The intermediate compound is dissolved in tetrahydrofuran under a nitrogen atmosphere and an ice bath, and then 3,5-dinitrobenzaldehyde, sodium cyanoborohydride and acetic acid are added, and the reaction is stirred at room temperature. After the reaction is completed, the solvent is removed under reduced pressure, and the crude product is separated and purified by a silica gel chromatography column to obtain the fluorescent probe for detecting formaldehyde.
3. The method for preparing a fluorescent probe for detecting formaldehyde according to claim 2, characterized in that: In step (1), the concentration of the ammonia methanol solution is 7 mol / L; the molar ratio of allyl dibutoxy borane to the ammonia methanol solution is (1-2):(4-10).
4. The method for preparing a fluorescent probe for detecting formaldehyde according to claim 2, characterized in that: In step (1), the stirring time is 15 minutes.
5. The method for preparing a fluorescent probe for detecting formaldehyde according to claim 2, characterized in that: In step (2), the concentration of the ammonia methanol solution is 7 mol / L; the molar ratio of the 3-hydroxy-4-(1-hydrogen-phenanthro[9,10-d]imidazol-2-yl)benzaldehyde, the ammonia methanol solution and water is 1:(4-15):(10-15).
6. The method for preparing a fluorescent probe for detecting formaldehyde according to claim 2, characterized in that: In step (2), the reaction time is 24 hours.
7. The method for preparing a fluorescent probe for detecting formaldehyde according to claim 2, characterized in that: In step (2), the developing solvent of the silica gel chromatography column is dichloromethane:methanol=30:
1.
8. The method for preparing a fluorescent probe for detecting formaldehyde according to claim 2, characterized in that: In step (3), the molar ratio of the intermediate compound, 3,5-dinitrobenzaldehyde, sodium cyanoborohydride and acetic acid is 1:(2-10):(5-10):(5-20).
9. The method for preparing a fluorescent probe for detecting formaldehyde according to claim 2, characterized in that: In step (3), the stirring reaction time is 12-24 hours; the developing solvent of the silica gel chromatography column is dichloromethane:methanol=30:
1.
10. Use of the fluorescent probe according to claim 1 or the fluorescent probe prepared by the preparation method according to any one of claims 2 to 9 in detecting formaldehyde.