Preparation method and application of picolinyl hydrazone multifunctional fluorescent probe

Abstract

The invention discloses a preparation method and application of a picolinyl hydrazone multifunctional fluorescent probe, relates to the field of analysis and detection, and in particular relates to a preparation method of a picolinyl hydrazone fluorescent probe and multi-response recognition of the picolinyl hydrazone fluorescent probe on zinc ions, aluminum ions, glyphosate and fluorine ions. The defect that an existing fluorescent probe cannot simultaneously respond to various cations and anions in different ways under the same test condition can be overcome. The preparation method of the fluorescent probe L disclosed by the invention comprises the step of carrying out condensation reaction on 2-methylthio-3-pyridine formyl hydrazine and 2-hydroxy-1-naphthaldehyde under a liquid phase condition. Under the action of 446 nm exciting light, the fluorescent probe prepared by the invention can realize differentiated response recognition on the wavelength and intensity of zinc ions and aluminum ions, and the complexes L-Zn < 2 + > and L-Al < 3 + > respectively realize fluorescence detection on glyphosate and fluorine ions. The fluorescent probe prepared by the invention has the advantages of strong specificity, high sensitivity and naked eye recognition in the use process, and can be used for differential fluorescence detection of various ions in a complex environment.

Description

Technical Field

[0001] The invention relates to the field of multi-ion detection, and in particular to a preparation method of a pyridylhydrazone derivative and application of the pyridylhydrazone derivative in multi-response identification of zinc ions, aluminum ions, glyphosate and fluoride ions. Background Art

[0002] The rapid development of industry has brought about increasingly serious environmental pollution problems. Excessive cations, anions and pesticides in the environment pose a serious threat to human health. For example, an imbalance in the content of zinc ions in the body can lead to neuronal dysfunction, inducing Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease; excessive intake of aluminum ions in the human body can be toxic, leading to various diseases such as Parkinson's disease, osteoporosis and breast cancer; as an essential component of human teeth and bones, when the concentration of fluoride ions in the human body is too high, it can cause fluoride poisoning, kidney, gastrointestinal and immune toxicity, leading to damage to the immune system and even death; and excessive intake of the pesticide glyphosate may harm the central nervous system, leading to respiratory, myocardial and neurological dysfunction, and even inducing cancer. Therefore, it is particularly important to achieve dynamic detection of multiple harmful ions in the environment.

[0003] Traditional ion detection methods, such as chromatography and mass spectrometry, can meet the needs to a certain extent, but these methods often require complex sample pretreatment and analysis steps, and are time-consuming and require professional equipment and operators, which limits their application in rapid on-site detection and large-scale sample analysis. Fluorescent probe detection is widely used in the detection of various substances because of its advantages such as simple operation, high sensitivity, good selectivity, real-time monitoring, visualization and on-site detection.

[0004] Pyridine is a nitrogen-containing six-membered heterocyclic compound with more stable chemical properties than benzene. The nitrogen atom on the pyridine ring has a pair of unshared electrons, which enables it to form complexes with a variety of Lewis acids. Pyridoylhydrazone is a class of derivatives prepared by the condensation reaction of pyridoylhydrazide and aldehyde. The C=N bond in the Schiff base structure is a commonly used coordination chemical ligand, and the pyridoylhydrazone derivatives have both C=N bond and C=O bond, which can provide more complexation sites. At the same time, the pyridoylhydrazone derivatives also have excellent fluorescence properties. Therefore, they have attracted much attention in the field of fluorescent material preparation. The present invention designs and prepares a novel pyridoylhydrazone fluorescent probe, which can achieve differential responses to four ions of zinc ion, aluminum ion, glyphosate and fluoride ion under the same test conditions. The response process has the advantages of simple operation, good specificity, high sensitivity, and naked eye recognition. Summary of the invention

[0005] The present invention aims to solve the deficiency that the existing fluorescent probe cannot respond to multiple cations and anions simultaneously and distinguishably under the same test conditions, and provides a preparation method and application of a four-response multifunctional fluorescent probe.

[0006] The present invention provides a pyridylhydrazone multifunctional fluorescent probe L, wherein the molecular structure of L is:

[0007]

[0008] The synthetic route of the fluorescent probe L is as follows:

[0009]

[0010] The preparation method of the probe L is as follows: 2-methylthio-3-pyridinecarboxylic acid hydrazide and 2-hydroxy-1-naphthaldehyde are condensed and reacted under liquid phase conditions.

[0011] The present invention utilizes the application of pyridylhydrazone fluorescent probe L in the multi-response detection of zinc ions, aluminum ions, glyphosate and fluoride ions.

[0012] Preferably, at an excitation wavelength of 446 nm, the fluorescence of the probe L at 514 nm is enhanced 10 times after recognizing zinc ions, and the fluorescence is quenched after adding glyphosate, with a quenching rate of 89%.

[0013] Preferably, at an excitation wavelength of 446 nm, the fluorescence of the probe L at 497 nm is enhanced by 71 times after recognizing aluminum ions, and the fluorescence is quenched after adding fluoride ions, with a quenching rate of 82%.

[0014] Furthermore, the detection limit of probe L for aluminum ions is as low as 1.66×10 -8 mol / L.

[0015] Furthermore, the action ratio of the probe L to the aluminum ion is 1:1.

[0016] Furthermore, the complex L-Al 3+ Resistant to P2O7 during fluoride ion detection 4- ,HCO3 - ,Cr2O7 2- ,Cl - , NO3 - ,Br - ,S2O3 2- ,I-,CH3COO - ,CO3 2- ,SO4 2- ,HSO4 - ,F - ,PO4 3- ,NO2 - interference.

[0017] Principle of the present invention:

[0018] The pyridylhydrazone fluorescent probe prepared by the present invention has a planar and large-scale π-conjugated structure, and can form a complex with zinc ions or aluminum ions through carbonyl, phenolic hydroxyl and imine bonds under the same test conditions. Due to the different properties of zinc ions and aluminum ions, the position and intensity of the fluorescence emission peak are different after the coordination reaction occurs, thereby achieving specific detection of zinc ions and aluminum ions. Glyphosate can remove zinc ions from the complex L-Zn 2+ Similarly, fluoride ions can displace aluminum ions from the complex L-Al 3+ The fluorescent probe is replaced and returns to the monomeric state, resulting in the recovery of the fluorescence effect, thereby realizing the fluorescence detection of glyphosate and fluoride ions.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) The pyridoylhydrazone derivative prepared by the present invention can realize the differential detection of multiple cations (zinc ions, aluminum ions) and multiple anions (glyphosate and fluoride ions) under the same test conditions, thus expanding the application of the probe.

[0021] 2) The fluorescent probe prepared by the present invention has novel structure, simple operation, excellent performance, reduces the synthesis work of the probe, and makes the fluorescent probe detection method more energy-saving and green. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Fluorescent probes 1 H NMR spectrum;

[0023] Figure 2 Fluorescent probes have selectivity for metal ion recognition;

[0024] Figure 3 Fluorescent probe for Al 3+ Fluorescence response anti-interference;

[0025] Figure 4 Fluorescent probes for different concentrations of Al 3+ Linear relationship diagram of fluorescence response;

[0026] Figure 5 Complex L-Zn 2+ Selective recognition of glyphosate;

[0027] Figure 6 Complex L-Al 3+ Selective recognition of fluoride ions;

[0028] Figure 7 Complex L-Al 3+ Recognition of fluoride ions in the presence of different anions;

[0029] Figure 8 Complex L-Al 3+ Linear relationship diagram of fluorescence response to different concentrations of fluoride ions;

[0030] Fig. 9 Complex L-Al 3+ Cyclic detection line graph of aluminum ions and fluoride ions; DETAILED DESCRIPTION

[0031] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0032] Specific implementation method 1: The molecular structure of a pyridylhydrazone multifunctional fluorescent probe L is:

[0033]

[0034] Specific implementation method 2: A method for preparing a pyridoylhydrazone multifunctional fluorescent probe L is as follows: 2-methylthio-3-pyridinecarboxylic acid hydrazide and 2-hydroxy-1-naphthaldehyde are condensed under liquid phase conditions to prepare the probe.

[0035] Specific implementation method three: Application of the fluorescent probe L in this implementation method in multi-response detection of zinc ions, aluminum ions, glyphosate and fluoride ions.

[0036] Specific embodiment 4: This embodiment differs from specific embodiment 3 in that: at an excitation wavelength of 446 nm, the fluorescence at 514 nm is enhanced 10 times after the probe recognizes zinc ions, and the fluorescence is quenched after adding glyphosate, with a quenching rate of 89%. Other aspects are the same as specific embodiment 3.

[0037] Specific embodiment 5: This embodiment is different from specific embodiment 3 or 4 in that: at an excitation wavelength of 446 nm, the fluorescence at 497 nm is enhanced by 71 times after the probe recognizes aluminum ions, and the fluorescence is quenched after adding fluoride ions, with a quenching rate of 82%. Other aspects are the same as specific embodiment 3 or 4.

[0038] Specific embodiment 6: This embodiment is different from the specific embodiment 5 in that the detection limit of probe L for aluminum ions is as low as 1.66×10 -8 mol / L. Other aspects are the same as those in the fifth embodiment.

[0039] Specific embodiment 7: This embodiment is different from specific embodiment 5 or 6 in that the action ratio of probe L to aluminum ion is 1:1. The rest is the same as specific embodiment 5 or 6.

[0040] Specific embodiment eight: This embodiment differs from specific embodiment five, six or seven in that: the complex L-Al 3+Resistant to P2O7 during fluoride ion detection 4- ,HCO3 - ,Cr2O7 2- ,Cl-,NO3 - ,Br - ,S2O3 2- ,I - ,CH3COO - ,CO3 2- ,SO4 2- ,HSO4 - ,F-,PO4 3- ,NO2 - The rest is the same as the fifth, sixth or seventh specific implementation.

[0041] The HEPES buffer solution is used in this embodiment to prevent the pH of the probe solution from changing, and at the same time to verify whether the probe can be used in cell experiments.

[0042] The embodiments of the present invention are described in detail below. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation schemes and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0043] Example 1: The preparation method of the fluorescent probe L is carried out according to the following steps:

[0044] In a 50 mL three-necked flask, 2-methylthio-3-pyridinecarboxylic acid hydrazide (0.183 g, 1 mmol), 2-hydroxy-1-naphthaldehyde (0.172 g, 1 mmol) and 30 mL of ethanol were added. After reflux reaction for 6 h, a light yellow solid was precipitated by cooling. After filtration, washing and drying, a pyridoylhydrazone derivative (0.276 g, 0.82 mmol) was obtained with a yield of 81.9%. 1 H NMR (300MHz, DMSO-d6) δ12.49 (s, 1H), 12.23 (s, 1H), 9.35 (s, 1H), 8.64 (d, J = 3.8 Hz, 1H), 8.28 (d, J = 8.7 Hz, 1H), 8.02 (d, J = 6.6 Hz, 1H), 7.93 (dd, J = 14.0, 8.4 Hz, 2H), 7.61 (t, J = 7.7 Hz, 1H), 7.42 (t, J = 7.6 Hz, 1H), 7.35-7.25 (m, 2H), 2.51 (s, 3H) ppm. 1 H NMR spectrum Figure 1 shown.

[0045] Example 2: The fluorescent probe L in this example selectively recognizes metal ions according to the following steps:

[0046] Take 3mL of fluorescent probe L solution (V DMSO :V 水 =95:5, HEPES 2.5 mM, pH = 7.4) in a cuvette, and 3 eq. of Hg 2+ Mg 2+ ,Pb 2+ ,Li + ,Bi 3+ ,Na + ,Cd 2+ ,K + ,Co 3+ ,Fe 3+ ,Ag + ,Cu 2+ ,Ca 2+ ,Ba 2+ ,Cr 3+ ,Cs + ,Al 3+ and Zn 2+ At an excitation wavelength of 446 nm, the fluorescence emission peak was measured and Zn was added. 2+ After that, obvious fluorescence was generated at 514nm, and the fluorescence was enhanced by 10 times. 3+ After addition, the fluorescence at 497nm was significantly enhanced, with the fluorescence enhancement being 71 times. However, the addition of other metal ions did not cause significant fluorescence changes. 2+ and Al 3+ Shows specific discrimination, the results are as follows Figure 2 shown.

[0047] Example 3: The anti-interference performance of the fluorescent probe L in this example on aluminum ion detection is carried out according to the following steps:

[0048] Take 3mL each time with a concentration of 1.0×10 -5 mol / L fluorescent probe solution, and 3eq. of Hg 2+ Mg 2+ ,Pb 2+ ,Li + ,Bi 3+ ,Na + ,Cd 2+ ,K + ,Co 3+ ,Fe 3+ ,Ag + ,Cu 2+ ,Ca 2+ ,Ba 2+ ,Cr 3+ ,Cs + The fluorescence intensity was measured at an excitation wavelength of 446 nm. Then 3 eq. of Al 3+The fluorescence intensity was measured again. The results were as follows Figure 3 As shown in the figure, data analysis shows that when other metal ions exist in the fluorescent probe solution, the fluorescence intensity of the system will not change. 3+ After that, remove Cu 2+ In addition, the fluorescence of the system was significantly enhanced. This shows that probe L exhibits excellent anti-interference ability in the presence of interfering cations and can reliably detect Al 3+ Specific detection.

[0049] Example 4: The detection limit of the fluorescent probe L for aluminum ions in this example is carried out according to the following steps:

[0050] Take 3mL of the solution with a concentration of 1.0×10 -5 mol / L fluorescent probe solution, 3 μL of the concentration of 1×10 -3 mol / L aluminum ion aqueous solution, and measure the fluorescence intensity. Plot the graph with aluminum ion concentration as the horizontal axis and fluorescence intensity as the vertical axis. The results are as follows Figure 4 As shown in the figure, data analysis shows that when the aluminum ion concentration is within 0-10 μM, the fluorescence intensity increases with the increase of aluminum ion concentration, and the fluorescence intensity and aluminum ion concentration show a good linear relationship. The fitting equation is Y=190.04X+49.75, R 2 =0.997. According to the calculation formula of detection limit 3σ / k, the detection limit of the probe molecule for aluminum ions is calculated to be 1.66×10 -8 mol / L. The probe can detect trace amounts of aluminum ions.

[0051] Example 5: Complex L-Zn 2+ Selective identification of glyphosate is carried out in the following steps:

[0052] Take 3mL of the solution with a concentration of 1.0×10 -5 mol / L complex L-Zn 2+ The solution was added with 3 eq. of glyphosate, trichlorfon, phosmet, dichlorvos, malathion, omethoate, dimethoate, ethoprophos, fenitrothion, methyl parathion, parathion and glufosinate in sequence, and the fluorescence intensity was measured at an excitation wavelength of 446 nm. The results are as follows. Figure 5 From the data analysis, it can be seen that after adding glyphosate, the fluorescence of the system is significantly quenched, and the quenching rate reaches 89%. However, when other pesticides are added, the fluorescence intensity does not change significantly. 2+ The system achieves specific recognition of glyphosate.

[0053] Example 6: Complex L-Al 3+ For the selective recognition of fluoride ions, follow the steps below:

[0054] Take 3mL of the solution with a concentration of 1.0×10 -5 mol / L complex L-Al 3+ solution, and then add 3eq. of P2O7 4- ,HCO3 - ,Cr2O7 2- ,Cl-,NO3 - ,Br - ,S2O3 2- ,I-,CH3COO - ,CO3 2- ,SO4 2- ,HSO4 - ,F-,PO4 3- ,NO2 - The fluorescence intensity of the solution was measured at an excitation wavelength of 446 nm. Figure 6 As shown in the data analysis, when fluoride ions were added, the fluorescence of the system was significantly quenched, and the quenching rate reached 82%. However, when other common anions were added, the fluorescence intensity did not change significantly. 3+ Specific recognition of fluoride ions was achieved.

[0055] Example 7: Complex L-Al 3+ To identify the fluoride ion resistance, follow these steps:

[0056] At a concentration of 1.0×10 -5 mol / L complex L-Al 3+ 3eq. of P2O7 were added to the solution. 4- ,HCO3 - ,Cr2O7 2- ,Cl - , NO3 - ,Br - ,S2O3 2- ,I - ,CH3COO - ,CO3 2- ,SO4 2- ,HSO4 - ,PO4 3- ,NO2 - Then, 3 eq. of fluoride ions were added in sequence, and the changes in fluorescence intensity were observed and recorded. The results are as follows Figure 7 From the data analysis, it can be seen that in the presence of other coexisting anions, fluorescence quenching can still be achieved after adding fluoride ions. 3+ The system recognizes fluoride ions without interference.

[0057] Example 8: Complex L-Al 3+For the fluoride ion detection limit, follow the steps below:

[0058] In the complex L-Al 3+ 4.5 μL of the solution was added each time to a concentration of 1×10 -3 mol / L fluoride ion aqueous solution, and measure the fluorescence intensity. The results are as follows Figure 8 From the data analysis, it can be seen that when the fluoride ion concentration is within 0-30μM, the fluorescence intensity decreases with the increase of fluoride ion concentration, and the fluorescence intensity and fluoride ion concentration show a good linear relationship. The fitting equation is Y=-124.55X+2152.82, R 2 =0.994. According to the calculation formula of detection limit 3σ / k, the complex L-Al 3+ The detection limit for fluoride ions is 2.75×10 -7 mol / L. Complex L-Al 3+ The system can realize trace detection of fluoride ions.

[0059] Example 9: The performance test of the fluorescent probe L for cyclic recognition of aluminum ions and fluoride ions was carried out according to the following steps:

[0060] At a concentration of 1.0×10 -5 1 eq. of aluminum ion solution was added to the mol / L probe solution, and the fluorescence emission peak intensity value at 497 nm was measured at an excitation wavelength of 446 nm. Then 3 eq. of fluoride ion aqueous solution was added, and the fluorescence emission peak intensity value at 497 nm was measured at an excitation wavelength of 446 nm. The above operation was repeated 5 times, and the fluorescence curve of the probe L cyclically identifying aluminum ions and fluoride ions was drawn. The results are shown in the figure. Fig. 9 As shown in the figure, the results of the cyclic experiment show that probe L can realize the fluorescence "off-on-off" relay recognition of aluminum ions and fluoride ions, and the performance is stable. The fluorescence intensity does not change significantly after more than 5 cycles of detection. This shows that the detection method has good reproducibility and shows the potential for practical application.

Claims

1. A pyridylhydrazone multifunctional fluorescent probe L, characterized in that The molecular structure of L is:

2. Preparation of a pyridylhydrazone multifunctional fluorescent probe L, characterized in that The preparation method of L is as follows: 2-methylthio-3-pyridinecarboxylic acid hydrazide and 2-hydroxy-1-naphthaldehyde are condensed under liquid phase conditions.

3. Use of the fluorescent probe L as claimed in claim 1 in multi-response detection of zinc ions, aluminum ions, glyphosate and fluoride ions.

4. The use according to claim 3, characterized in that At an excitation wavelength of 446 nm, the fluorescence of probe L at 514 nm increased 10 times after recognizing zinc ions, and the fluorescence was quenched after adding glyphosate, with a quenching rate of 89%.

5. The use according to claim 3, characterized in that At an excitation wavelength of 446 nm, the fluorescence of probe L at 497 nm was enhanced by 71 times after recognizing aluminum ions, and the fluorescence was quenched after adding fluoride ions, with a quenching rate of 82%.

6. The use according to claim 5, characterized in that The detection limit of probe L for aluminum ions is as low as 1.66×10 - 8 mol / L.

7. The use according to claim 5, characterized in that The action ratio of probe L to aluminum ions is 1:

1.

8. The use according to claim 5, characterized in that Complex L-Al 3+ Resistant to P2O7 during fluoride ion detection 4- ,HCO3 - ,Cr2O7 2- ,Cl - , NO3 - ,Br - ,S2O3 2- ,I - ,CH3COO - ,CO3 2- ,SO4 2- ,HSO4 - ,F - ,PO4 3- ,NO2 - interference.

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