A method for detecting Cu 2+ and CN - Water-soluble polymer coumarin fluorescent probe and its preparation method and application

Abstract

A method for detecting Cu 2+ and CN ‑ Water-soluble polymer coumarin fluorescent probe and its preparation method and application, which involves detecting Cu 2+ and CN ‑ A fluorescent probe, its preparation method, and application. This invention addresses the technical problem that existing fluorescent probes have poor water solubility, leading to difficulty in application in pure water. The structural formula of the fluorescent probe of the present invention is: #imgabs0#, wherein m:n = (22-23):1. Preparation method: COMN is synthesized using 7-diethylaminocoumarin-3-formylhydrazide and diisocyanoethyl methacrylate; using azobisisobutyronitrile as a catalyst, COMN and acrylamide are polymerized to obtain a water-soluble fluorescent probe material, which is used to detect Cu in aqueous solution. 2+ and CN ‑ The minimum detection limits are 7.2nM and 1.27nM respectively, which can be used in the fields of biological imaging and disease detection.

Description

Technical Field

[0001] The present invention belongs to the field of fluorescent probe materials and their preparation, and specifically relates to a method for detecting Cu 2+ and CN - Water-soluble polymer coumarin fluorescent probe and its preparation method and application. Background Art

[0002] Copper ions are essential trace elements for maintaining life in the human body. Copper ion deficiency can lead to anemia, skeletal dysplasia, and decreased immunity, while excessive copper ion levels can cause central nervous system dysfunction, renal damage, and liver dysfunction. Furthermore, as a pollutant, copper ion emissions exceeding standards pose a significant threat to the environment and ecosystems. Therefore, copper ion detection is crucial for maintaining human health and protecting the ecological environment.

[0003] Cyanide is recognized as one of the most toxic compounds in nature. Its toxicity is primarily caused by the release of cyanide ions in the body. Cyanide ions quickly bind to the trivalent iron in cytochrome enzymes, inhibiting their activity and preventing oxygen utilization in human tissues, leading to tissue defects. Ingestion of small amounts of cyanide ions can cause chest tightness, dizziness, nausea, and vomiting. Ingestion of large amounts can cause loss of consciousness, dilated pupils, and rapid death. Therefore, cyanide ion detection is crucial for maintaining human health.

[0004] Traditional ion detection methods include suppressed conductivity detection, pulsed amperometric detection, and post-column derivatization, but they generally suffer from disadvantages such as high cost and difficult operation. Compared with these methods, fluorescent probe methods have attracted widespread attention due to their advantages such as high sensitivity, good selectivity, and fast response speed. Currently, there are many reports on fluorescent probes, but most of them lack practicality. A key issue is that most fluorescent probes require pure aqueous solution for application, while most fluorescent probes can only work in mixed solvents of organic solvents and water. This results in limitations in the application of fluorescent probes in pure water systems. Summary of the Invention

[0005] The present invention aims to solve the technical problem that the existing fluorescent probes have poor water solubility and are difficult to use in pure water, and provide a method for detecting Cu 2+ and CN - A water-soluble polymer coumarin fluorescent probe and its preparation method and application, the fluorescent probe has good water solubility and can detect Cu in a pure water system 2+ and CN - .

[0006] The detection Cu 2+ and CN -The water-soluble polymer coumarin fluorescent probe has the structural formula:

[0007] Wherein m:n=(22~23):1.

[0008] The above detection Cu 2+ and CN - The preparation method of the water-soluble polymer coumarin fluorescent probe is carried out according to the following steps:

[0009] 1. Dissolve 7-diethylaminocoumarin-3-carboxylic acid hydrazide in solvent I, add diisocyanoethyl methacrylate dropwise, and react at room temperature for 0.5 to 1 hour. After the reaction is complete, remove solvent I and unreacted diisocyanoethyl methacrylate to obtain a solid phase, which is then vacuum-dried to obtain ((7-diethylaminocoumarin-3-amido)ureido)ethyl methacrylate (COMN).

[0010] 2. Dissolve the COMN, acrylamide and azobisisobutyronitrile (AIBN) obtained in step 1 in solvent II, place the obtained mixed solution in a single-necked bottle, heat to 66-70°C under N2 protection and react for 12-13 hours; after the reaction is completed, remove solvent II and unreacted acrylamide and AIBN, and vacuum dry the obtained solid phase to obtain the detection Cu 2+ and CN - A water-soluble polymer coumarin fluorescent probe, it is a yellow powder.

[0011] Furthermore, the method for removing solvent I in step 1 is suction filtration or filtration.

[0012] Furthermore, the solvent I in step 1 is ethanol or methanol.

[0013] Furthermore, the molar ratio of ((7-diethylaminocoumarin-3-amide)ureido)ethyl methacrylate, acrylamide and azobisisobutyronitrile described in step 2 is (0.012-0.021):1:(0.005-0.008).

[0014] Furthermore, the solvent II in step 2 is tetrahydrofuran (THF).

[0015] The above detection Cu 2+ and CN - The application of water-soluble polymer coumarin fluorescent probe is to detect Cu in aqueous solution using this fluorescent probe 2+ and CN - .

[0016] The preparation route of the fluorescent probe of the present invention is as follows:

[0017]

[0018] The fluorescent probe of the present invention has strong autofluorescence. After being excited by 425nm visible light, it has a strong fluorescence signal at 489nm. 2+ After that, the fluorescence intensity decreased significantly. - The fluorescence intensity gradually recovered after that. The detection mechanism is that the nitrogen and oxygen atoms in COMN react with Cu 2+ After coordination, Cu 2+ The unpaired electrons in the d orbital of the probe are transferred to the ground state of the probe to initiate the PET process, resulting in fluorescence quenching. - Later, due to CN - With Cu 2+ The PET process is inhibited, and the fluorescence of the system is restored. 2+ and CN - The fluorescence intensity decreases (increases) and Cu 2+ and CN - The fluorescence intensity of the fluorescent probe is similar to that of Cu 2+ and CN - The concentration shows a good linear relationship, and the Cu 2+ and CN - The linear ranges of concentration were 0-30μM and 0-180μM, respectively, and the minimum detection limits were 7.2nM and 1.27nM, respectively. 2+ and CN - The fluorescent probe compound exhibits high sensitivity and excellent selectivity, and can be detected in pure aqueous solutions, making it convenient and effective in environmental applications. The polyacrylamide medium also exhibits excellent biocompatibility, biodegradability, and cell permeability, making it suitable for biological imaging and disease detection. Furthermore, the fluorescent probe compound is a solid powder, offering advantages such as ease of use and storage, simple synthesis, high yield, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the H NMR spectrum of fluorescent probes P, COMN and acrylamide;

[0020] Figure 2 It is the infrared spectrum of fluorescent probes P, COMN and acrylamide;

[0021] Figure 3 It is a fluorescent probe P to detect Cu 2+ (0~30μM) fluorescence spectrum;

[0022] Figure 4 It is a fluorescent probe P / Cu2+ Detection of CN - (0~180μM) fluorescence spectrum;

[0023] Figure 5 This is a bar graph of the competition experiment of fluorescent probe P against common cations;

[0024] Figure 6 P / Cu 2+ Bar graph for anion-selective competition experiments. DETAILED DESCRIPTION

[0025] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0026] Example 1: Detection of Cu in this example 2+ and CN - The preparation method of the water-soluble polymer coumarin fluorescent probe is carried out according to the following steps:

[0027] 1. Weigh 59 mg (0.22 mmol) of 7-diethylamino-coumarin-3-carboxylic acid hydrazide into a 50 mL three-necked flask, add 15 mL of anhydrous ethanol to the flask, and heat slightly to dissolve it completely. Then, add 0.1 mL (0.71 mmol) of isocyanoethyl methacrylate dropwise to the system and stir at room temperature for 1 hour. Then, filter the reaction solution, wash the solid matter with anhydrous ethanol three times, and dry to obtain COMN.

[0028] 2. 50 mg (0.12 mmol) of COMN, 400 mg (5.63 mmol) of acrylamide (AM), 5 mg of AIBN (0.031 mmol) and 10 mL of tetrahydrofuran (THF) were added into a single-necked bottle in sequence. The temperature was slowly raised to 70 ° C under N2 protection and the reaction was carried out for 12 hours. The reaction solution was filtered, and the solid matter was washed 3 times with THF and vacuum dried to obtain the detection Cu 2+ and CN - A water-soluble polymer coumarin fluorescent probe, which is a yellow powder, represented by P.

[0029] Figure 1 is the AM, COMN and P in Example 1 1 H NMR spectrum, from Figure 1It can be seen that P appears at around 9.94ppm and 8.27ppm on the amide hydrogen of COMN, the characteristic hydrogen on carbon 4 on the parent nucleus of coumarin appears at 8.67ppm, and the characteristic hydrogen on the benzene ring appears at 6.40ppm~7.71ppm, indicating that AM and COMN are successfully polymerized. The detection Cu prepared in this example 2+ and CN - The structural formula of the water-soluble polymer coumarin fluorescent probe is:

[0030] m:n=22.87:1, Mz+1=20467, representing the average molecular weight of the polymer; n=4.19%, representing the COMN content in P.

[0031] Figure 2 This is the infrared spectrum of AM, COMN and P in Example 1. The wave number in the spectrum is 3359.56 cm -1 Nearby is the asymmetric stretching vibration peak of the NH bond in the primary amine, 1680.12 cm -1 Nearby is the stretching vibration characteristic peak of C=O in the amide group, which proves that both AM and P contain a large number of amide groups (-CONH2). In the IR spectra of AM and COMN, 3030.56 cm -1 The stretching vibration of the unsaturated bond (C=CH) near 987.42 cm -1 The deformation vibration peak of the unsaturated bond (C=CH) nearby disappears in the spectrum of P, indicating that C=C is converted into CC, proving that the monomer undergoes copolymerization. In addition, the wave number 2933.34 cm -1 and 2871.62cm -1 The characteristic peaks of CH stretching vibration of methylene and methyl groups on COMN appeared nearby at wave number 1619.99 cm -1 、1511.99cm -1 and 1452.21cm -1 The characteristic peak of C=C stretching vibration of the benzene ring on COMN appeared nearby, further proving that AM and COMN underwent copolymerization.

[0032] The detection Cu prepared in Example 1 was used 2+ and CN - The water-soluble polymer coumarin fluorescent probe was used to detect ions. The specific process was as follows: deionized water was used as the solvent to prepare a 0.2047 g / L probe stock solution of the fluorescent probe prepared in Example 1. Detection of different concentrations of Cu 2+ (0~30μM), the changes in the fluorescence intensity of the system, such as Figure 3 As shown; then different concentrations of CN were added to the system -(0~180μM), and record the changes in the fluorescence intensity of the system again, such as Figure 4 The fluorescent probe is excited by 425nm visible light and has a strong fluorescence signal at 489nm. 2+ After adding CN - Afterwards, the fluorescence signal gradually recovered.

[0033] The detection Cu prepared in Example 1 2+ and CN - Water-soluble polymer coumarin fluorescent probes for the detection of Cu 2+ The process of the competitive selection experiment is as follows: set up different experimental groups P (0.2047g / L), record the changes in the fluorescence intensity of the system when different metal cations (30μM) are present. Then, add the same amount of Cu as the metal cation to all the above systems. 2+ , and record the changes in the fluorescence intensity of the system again. The cation selection competition experiment bar chart is as follows Figure 5 As shown in the figure, it can be seen that probe P can specifically recognize Cu by fluorescence. 2+ ; When other cations (Fe 3+ ,Co 2+ ,Zn 2+ ,Ag + ,Cd 2+ ,Pb 2+ ,Cr 3+ ,Hg 2+ ,Ni 2+ ,Al 3+ ,K + ,Ca 2+ ,Na + ,Mg 2+ ) and Cu 2+ When the two cations are present at the same time, the fluorescence intensity of the probe P is still significantly quenched. This indicates that the presence of other cations has a significant effect on the interaction between P and Cu. 2+ The process of action has little interference, P has little effect on Cu 2+ Has higher selectivity.

[0034] The detection Cu prepared in Example 1 2+ and CN - Water-soluble polymer coumarin fluorescent probes for detecting CN - The process of the anti-interference test is as follows: set different experimental groups P / Cu 2+ (0.2047 g / L, 30 μM), and record the changes in the fluorescence intensity of the system when different anions (180 μM) are present. Then, the same equivalent of CN is added to all the above systems. - , record the changes in the fluorescence intensity of the system again, and obtain the anion competition experiment bar graph as shown in Figure 6 As shown in the figure, it can be seen that P / Cu 2+ Can specifically identify CN with fluorescence - ; When other anions (F - ,Cl - ,Br - ,I - ,HSO4 - ,H2PO4 - ,AcO - ) and CN - When both P and Cu are present, 2+ The fluorescence intensity of P / Cu 2+ With CN - There is little interference between the effects of P / Cu 2+ CN - Has higher selectivity.

Claims

1. A method for detecting Cu 2+ and CN - A water-soluble polymer coumarin fluorescent probe, characterized in that The structural formula of the fluorescent probe is: , where m:n=(22~23):

1.

2. A method for detecting Cu according to claim 1 2+ and CN - The method for preparing a water-soluble polymer coumarin fluorescent probe is characterized in that The method proceeds as follows:

1. Dissolve 7-diethylaminocoumarin-3-carboxylic acid hydrazide in solvent I, add diisocyanoethyl methacrylate dropwise, and react at room temperature for 0.5-1 hour. After the reaction is complete, remove solvent I and unreacted diisocyanoethyl methacrylate to obtain a solid phase, which is then vacuum-dried to obtain ((7-diethylaminocoumarin-3-amido)ureido)ethyl methacrylate, represented by COMN.

2. Dissolve the COMN, acrylamide and azobisisobutyronitrile obtained in step 1 in solvent II, and place the obtained mixed solution in a single-necked bottle. Heat to 66-70°C under N2 protection and react for 12-13 hours. After the reaction is completed, remove solvent II and unreacted acrylamide and azobisisobutyronitrile to obtain a solid phase substance, which is vacuum dried to obtain the detection Cu 2+ and CN - Water-soluble polymer coumarin-based fluorescent probe.

3. A method for detecting Cu according to claim 2 2+ and CN - The method for preparing a water-soluble polymer coumarin fluorescent probe is characterized in that: The method for removing solvent I described in step 1 is filtration.

4. A method for detecting Cu according to claim 3 2+ and CN - The method for preparing a water-soluble polymer coumarin fluorescent probe is characterized in that: The method for removing solvent I described in step 1 is suction filtration.

5. A method for detecting Cu according to claim 2 or 3. 2+ and CN - The method for preparing a water-soluble polymer coumarin fluorescent probe is characterized in that: The solvent I described in step 1 is ethanol or methanol.

6. A method for detecting Cu according to claim 2 or 3. 2+ and CN - The method for preparing a water-soluble polymer coumarin fluorescent probe is characterized in that: The molar ratio of COMN, acrylamide and azobisisobutyronitrile described in step 2 is (0.012-0.021):1:(0.005-0.008).

7. A method for detecting Cu according to claim 2 or 3. 2+ and CN - The method for preparing a water-soluble polymer coumarin fluorescent probe is characterized in that: The solvent II described in step 2 is tetrahydrofuran.

8. A method for detecting Cu according to claim 1 2+ and CN - The application of a water-soluble polymer coumarin fluorescent probe is characterized in that This application is to use this fluorescent probe to detect Cu in aqueous solution 2+ and CN - .

Images