Camphor-based fluorescent probe for continuously detecting gallium ions and glyphosate as well as preparation method and application of camphor-based fluorescent probe

Abstract

The invention discloses a camphor-based fluorescent probe for continuously detecting gallium ions and glyphosate as well as a preparation method and application of the camphor-based fluorescent probe. The fluorescent probe is 2, 3-bis ((2-hydroxy-5-((4, 7, 7-trimethyl-3-oxo-bicyclo [2.2. 1] heptyl-2-subunit) methyl) benzylidene) amino) maleic nitrile, and the structural formula of the fluorescent probe is shown in the description. According to the invention, 3-(3-formyl-4-hydroxybenzylidene) camphor is used as a raw material, and is subjected to a condensation reaction with 2, 3-diamino maleic nitrile, such that 2, 3-bis ((2-hydroxy-5-((4, 7, 7-trimethyl-3-oxo-bicyclo [2.2. 1] heptyl-2-subunit) methyl) benzylidene) amino) maleic nitrile is obtained, and the 2, 3-bis ((2-hydroxy-5-((4, 7, 7-trimethyl-3-oxo-bicyclo [2.2. 1] heptyl-2-subunit) methyl) benzylidene) amino) maleic nitrile is obtained. The compound can be specifically subjected to complexation reaction with gallium ions, the fluorescence color of a solution is changed from colorless to green under irradiation of ultraviolet light with the wavelength of 365 nm, and the fluorescence of the solution is changed from green to colorless after glyphosate and the gallium ions have a stronger coordination effect, so that the fluorescence of the solution is changed from green to colorless after the glyphosate is added into the solution. Therefore, the compound can be used as a fluorescent probe for continuously detecting gallium ions and glyphosate.

Description

Technical Field

[0001] The invention belongs to the technical field of fine organic synthesis and relates to a camphor-based fluorescent probe for continuous detection of gallium ions and glyphosate, and a preparation method and application thereof. Background Art

[0002] Gallium is a highly valuable rare metal element with extensive applications in a variety of fields, including metal catalysts, semiconductor synthesis, and solar cells. Gallium citrate is also commonly used as a contrast agent in magnetic resonance imaging (MRI). However, the frequent use of gallium-based reagents in industrial production has inevitably caused certain ecological harm. Glyphosate is recognized as a highly effective organophosphorus pesticide and is widely used in agriculture. However, due to its aquatic use and excellent environmental stability, its indiscriminate use may lead to agricultural product contamination and environmental degradation. Furthermore, glyphosate has been classified as a Group 2A carcinogen by the International Agency for Research on Cancer (IARC). Excessive glyphosate intake can lead to a variety of physiological disorders, including endocrine disruption, neuromuscular dysfunction, and various chronic diseases. Therefore, it is crucial to develop reliable tools for detecting gallium ions and glyphosate residues in food and biological systems.

[0003] Currently, the main methods for detecting gallium ions and glyphosate include gas chromatography, ion chromatography, high-performance liquid chromatography, and electrochemical analysis. Compared with traditional detection methods, fluorescent probes have unique advantages, such as rapid detection, simple synthesis, high sensitivity, and good selectivity, and have developed into a highly effective analytical detection method. However, there are currently no reports on the synthesis of a camphor-based fluorescent probe for the continuous detection of gallium ions and glyphosate using 3-(3-formyl-4-hydroxybenzylidene) camphor. Summary of the Invention

[0004] In response to the deficiencies in the prior art, the present invention aims to provide a camphor-based fluorescent probe for the continuous detection of gallium ions and glyphosate that meets usage requirements. Another technical problem to be solved by the present invention is to provide a method for preparing 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile. Another technical problem to be solved by the present invention is to provide an application of the aforementioned 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A camphor-based fluorescent probe for continuous detection of gallium ions and glyphosate is 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile, and its structural formula is:

[0007]

[0008] The method for preparing a camphor-based fluorescent probe for continuous detection of gallium ions and glyphosate comprises the following steps: using 3-(3-formyl-4-hydroxybenzylidene) camphor as a raw material, and performing a condensation reaction with 2,3-diaminomaleonitrile to obtain 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile.

[0009] (1) 1 mol of 2,3-diaminomaleonitrile, 2.1-3.1 mol of 3-(3-formyl-4-hydroxybenzylidene) camphor, 10-15 mL of concentrated sulfuric acid, and 25-40 L of anhydrous ethanol were sequentially added to a three-necked flask equipped with a stirrer, and the mixture was refluxed at 80°C for 8-10 h. The reaction was monitored by TLC until the raw material spot completely disappeared, at which point the reaction was stopped.

[0010] (2) After the reaction solution was cooled, a solid precipitated, which was filtered and recrystallized from anhydrous ethanol to obtain a brick-red powder of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)butenenitrile.

[0011] 2,3-Bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile specifically complexes with gallium ions. Under 365nm ultraviolet light, the fluorescence of the solution changes from colorless to green. Due to the stronger coordination effect of glyphosate with gallium ions, the fluorescence of the solution changes from green to colorless after adding glyphosate. This compound can sensitively detect the content of gallium ions and glyphosate in solutions, with detection limits as low as 22.7nM and 19.5nM, respectively.

[0012] Beneficial Effects: Compared with the prior art, the present invention uses 3-(3-formyl-4-hydroxybenzylidene) camphor as a raw material, undergoes a condensation reaction with 2,3-diaminomaleonitrile to obtain 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile. This compound can continuously detect the content of gallium ions and glyphosate in a solution, has many advantages such as easy synthesis, rapid response, good selectivity, and high sensitivity, and has very good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The fluorescence spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile reacting with different concentrations of gallium ions are shown;

[0014] Figure 2 The fluorescence spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile complexed with gallium ions and then reacted with different concentrations of glyphosate;

[0015] Figure 3 The fluorescence spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile reacting with different metal ions are shown.

[0016] Figure 4 The fluorescence spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)butenenitrile complexed with gallium ions and then reacted with different organic pesticides. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to specific embodiments.

[0018] Example 1

[0019] Preparation of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile, the reaction formula is as follows:

[0020]

[0021] The specific steps are as follows:

[0022] Preparation of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile:

[0023] 1 mol of 2,3-diaminomaleonitrile, 2.1-3.1 mol of 3-(3-formyl-4-hydroxybenzylidene)camphor, 10-15 mL of concentrated sulfuric acid, and 25-40 L of anhydrous ethanol were sequentially added to a three-necked flask equipped with a stirrer. The mixture was refluxed at 80°C for 8-10 hours and monitored by TLC until the starting material spots disappeared, at which point the reaction was stopped. The reaction solution was cooled to precipitate a solid, which was filtered and recrystallized from anhydrous ethanol to obtain a brick-red powder of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile in a yield of 63%. 1 H NMR (600MHz, DMSO-d6) δ: 11.55 (s, 2H), 9.13 (s, 2H), 8.29 (d, J=2.3Hz, 2H), 7.69 (d, J=8.7Hz, 2H), 7.16-7.04 (m, 4H), 3 .21(d, J=4.2Hz, 2H), 2.24(m, 2H), 1.82-1.76(m, 2H), 1.48(m, 2H), 1.38(m, 2H), 0.98(s, 6H), 0.94(s, 6H), 0.75(s, 6H); 13 C NMR (151MHz, CDCl3) δ: 207.83, 167.50, 162.25, 141.61, 138.12, 134.94, 128.36, 125.28, 118.75, 118.24, 109.74, 56.99, 49.08, 46.78, 30.63, 29.63, 25.93, 20.55, 18.24, 9.20; HRMS (m / z): [M+H] + calcd for C 40 H 40 N4O4, 641.3128; found, 641.3130.

[0024] Example 2

[0025] 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile was prepared into a 20 μM aqueous solution (DMSO / H2O=2 / 8), and gallium ions were dissolved in the aqueous solution to prepare solutions with concentrations of 0, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, and 150 μM, respectively. The fluorescence emission spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile in the presence of different concentrations of gallium ions were measured on a fluorescence spectrophotometer using fluorescence spectrometry, as shown in FIG. Figure 1 The results showed that as the gallium ion concentration in the solution increased from 0 μM to 150 μM, the fluorescence emission intensity of the compound at 530 nm gradually decreased. This suggests that the compound can be used as a fluorescent probe for sensitive detection of glyphosate.

[0026] Example 3

[0027] 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)butenenitrile was prepared into a 20 μM aqueous solution (DMSO / H2O=2 / 8), gallium ions were dissolved in the aqueous solution to prepare a solution with a concentration of 150 μM, and glyphosate was dissolved in an aqueous solution (DMSO / H2O=2 / 8) to prepare solutions with concentrations of 0, 18, 36, 54, 72, 90, 108, 126, 144, 162, 180, 198, 216, 234, and 250 μM, respectively. The fluorescence emission spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile complexed with gallium ions and then reacted with different concentrations of glyphosate were measured on a fluorescence spectrophotometer using a fluorescence spectrophotometer. Figure 2 The results showed that as the glyphosate concentration in the solution increased from 0 μM to 250 μM, the fluorescence emission intensity of the compound at 530 nm gradually weakened. This suggests that the compound can be used as a fluorescent probe for sensitive detection of glyphosate.

[0028] Example 4

[0029] 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile was prepared into a 20 μM aqueous solution (DMSO / H2O=2 / 8), and different metal ions were dissolved in the aqueous solution to prepare a 200 μM solution. The fluorescence emission spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile in the presence of different metal ions were measured on a fluorescence spectrophotometer using fluorescence spectrometry, as shown in FIG. Figure 3 The compound exhibited a significant increase in fluorescence emission intensity at 530 nm after reaction with gallium ions. However, the compound's fluorescence spectrum remained unchanged when zinc, target, nickel, manganese, chromium, barium, iron, indium, magnesium, sodium, copper, aluminum, mercury, gallium, silver, calcium, and chromium ions were added for comparison. This suggests that the compound can be used as a fluorescent probe for the selective detection of gallium ions.

[0030] Example 4

[0031] 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile was prepared into a 20 μM aqueous solution (DMSO / H2O=2 / 8), gallium ions were dissolved in the aqueous solution to prepare a 150 μM solution, and organic pesticides were dissolved in an aqueous solution (DMSO / H2O=2 / 8) to prepare a 250 μM solution. The fluorescence emission spectra of 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile after complexing with gallium ions and then reacting with different organic pesticides were measured on a fluorescence spectrophotometer using fluorescence spectrometry, as shown in the following example: Figure 4 The fluorescence emission intensity of this compound at 530 nm decreased significantly after reaction with glyphosate. However, when dichlorvos, acetamiprid, cyhalothrin, chlorpyrifos, phoxim, bifenthrin, trichlorfon, glufosinate, methomyl, imidacloprid, chlorthiazolin, dimethoate, deltamethrin, carbofuran, thiacloprid, carbaryl, and methyl parathion were added for comparison, the fluorescence spectrum of this compound did not change significantly. This indicates that this compound can be used as a fluorescent probe for the selective detection of glyphosate.

Claims

1. A camphor-based fluorescent probe for continuous detection of gallium ions and glyphosate, and its preparation method and application, characterized in that: Its structural formula is:

2. The method for preparing a camphor-based fluorescent probe for continuous detection of gallium ions and glyphosate according to claim 1, wherein: The steps include: 3-(3-Formyl-4-hydroxybenzylidene) camphor is condensed with 2,3-diaminomaleonitrile to obtain 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo{ 2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile.

3. The method for preparing a camphor-based fluorescent probe for continuous detection of gallium ions and glyphosate according to claim 2, wherein: In the presence of concentrated sulfuric acid, 3-(3-formyl-4-hydroxybenzylidene) camphor reacts with 2,3-diaminomaleonitrile to give 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[ 2.2.1] hept-2-ylidene) methyl) benzylidene) amino) maleonitrile, the specific preparation method comprises: (1) 1 mol of 2,3-diaminomaleonitrile, 2.1-3.1 mol of 3-(3-formyl-4-hydroxybenzylidene) camphor, 10-15 mL of concentrated sulfuric acid, and 25-40 L of anhydrous ethanol were sequentially added to a three-necked flask equipped with a stirrer, and the mixture was refluxed at 80°C for 8-10 h. The reaction was monitored by TLC until the raw material spot disappeared, at which point the reaction was stopped. (2) After the reaction solution was cooled, a solid was precipitated, which was filtered and recrystallized from anhydrous ethanol to obtain a brick red powder 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[ 2.2.1]hept-2-ylidene)methyl)benzylidene)amino)maleonitrile.

4. The novel camphor-based fluorescent probe 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[ 2.2.1] Application of (heptyl-2-ylidene)methyl)benzylidene)amino)butenenitrile in the detection of glyphosate.

5. The use according to claim 4, characterized in that 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[ 2.2.1] (2-Hept-2-ylidene)methyl)benzylidene)amino)maleonitrile can specifically undergo a complex reaction with gallium ions. Under ultraviolet light with a wavelength of 365 nm, the fluorescence color of the solution changes from colorless to green. Since glyphosate has a stronger coordination effect with gallium ions, the fluorescence of the solution changes from green to colorless after glyphosate is added to the solution.

6. The use according to claim 4, characterized in that 2,3-bis((2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[ 2.2.1] (2-Heptyl) (methyl) (benzylidene) (amino) (maleonitrile) can continuously detect the content of gallium ions and glyphosate in solution, with detection limits as low as 22.7 nM and 19.5 nM, respectively.

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