Fluorescent material based on dicyanoethylene as well as preparation method and application of fluorescent material

Abstract

The invention relates to the technical field of biogenic amine detection, in particular to a dicyanoethylene-based fluorescent material as well as a preparation method and application thereof. After the biogenic amine is in contact with the glass surface fluorescent probe, due to the nucleophilic characteristic of the biogenic amine, the biogenic amine can be subjected to nucleophilic substitution reaction with a probe molecule dicyanovinyl group to generate an imine chemical structure. As the electron-withdrawing capability of dicyanoethylene is stronger than that of imine, the intramolecular charge transfer effect of probe molecules is greatly reduced, so that blue shift of absorption and luminescence properties of the probe molecules is caused, and after the fluorescent probe is loaded on the surface of glass, the fluorescence intensity of the fluorescent probe is improved. The formed dicyanoethylene-based fluorescent material provides a solution for the technical problem that the existing biogenic amine detection mode is inconvenient.

Description

Technical Field

[0001] The present invention relates to the technical field of biogenic amine detection, and particularly relates to a fluorescent material based on dicyanoethylene, a preparation method thereof, and an application thereof. Background Art

[0002] Meat and its products are an important part of human daily diet, and their freshness and safety are crucial. However, due to inevitable microbial activities, meat is prone to deterioration during storage and will produce a series of toxic and harmful substances during storage and transportation. Among them, biogenic amines are one of the key indicators of food spoilage. These biogenic amines gradually accumulate during the spoilage process of meat, which not only affects the taste and nutritional value of food, but more importantly, the intake of high concentrations of biogenic amines will cause a series of adverse reactions, such as headache, hypotension or hypertension, nausea, palpitation, and even lead to serious consequences, such as nephrotoxicity and cerebral hemorrhage. Existing methods such as low-temperature freezing or high-temperature heating are ineffective in eliminating biogenic amines in meat, making the monitoring and control of biogenic amines an urgent problem in the field of food safety.

[0003] Currently, chromatographic analysis methods, capillary electrophoresis, and electrochemical techniques are the main means for biogenic amine detection. However, these methods have limitations such as complex sample pretreatment, expensive equipment, time-consuming operations, and the need for skilled personnel, which severely limit their wide application in biogenic amine monitoring. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a fluorescent material based on dicyanoethylene, a preparation method thereof, and an application thereof, so as to solve the technical problem of the inconvenient use of existing biogenic amine detection methods.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: The first purpose of the present invention is to provide a fluorescent material based on dicyanoethylene, the fluorescent material is a fluorescent probe, and the fluorescent probe has a chemical structural formula as shown in Formula I: ; Wherein, R is hydrogen or , is the connection site; When R is , the fluorescent probe is loaded on a matrix with amino groups on its surface.

[0006] The second purpose of the present invention is to provide a preparation method of the above fluorescent material based on dicyanoethylene. When R is hydrogen, the preparation method includes the following steps: Using compound b and compound 3 as raw materials, in a reaction system of a transition metal catalyst, a base and a first solvent, a coupling reaction is carried out at 100 °C to 110 °C under an inert gas atmosphere to obtain compound 4; the synthesis reaction formula is as follows: 。

[0007] Using compound 4 and malononitrile as raw materials, in a second solvent reaction system, a first condensation reaction is carried out at 100 °C to 110 °C to obtain a fluorescent probe, which is a fluorescent material. The synthesis reaction formula is as follows: 。

[0008] Furthermore, the molar ratio of compound 3 to compound b is 1:1.1 to 1.3, and the reaction time of the substitution reaction is 5.5 h to 6.5 h; the molar ratio of compound 4 to malononitrile is 1:2.0 to 3.0, and the reaction time of the first condensation reaction is 30 min to 60 min.

[0009] Furthermore, when R is , the preparation method of the fluorescent probe includes the following steps: Using compound 3 and BBr3 as raw materials, in a third solvent reaction system, a demethylation reaction is carried out at room temperature under an inert gas atmosphere to obtain compound 5; the synthesis reaction formula is as follows: 。

[0010] Using compound 5, ethyl 4-bromobutyrate and potassium carbonate as raw materials, in a fourth solvent reaction system, a nucleophilic substitution reaction is carried out at 55 °C to 65 °C to obtain compound 6; the synthesis reaction formula is as follows: 。

[0011] Using compound 6 and compound b as raw materials, in a reaction system of a transition metal catalyst, potassium carbonate and a fifth solvent, a coupling reaction is carried out at 100 °C to 110 °C under an inert gas atmosphere to obtain compound 7; the synthesis reaction formula is as follows: 。

[0012] Under acidic conditions, compound 7 is hydrolyzed at room temperature to obtain compound 8; the synthesis reaction formula is as follows: 。

[0013] Using compound 8 and N-hydroxysuccinimide as raw materials, in a reaction system of a sixth solvent and a condensing agent, an esterification reaction is carried out at room temperature to obtain compound 9; the synthesis reaction formula is as follows: 。

[0014] The substrate is silanized to obtain a substrate with amino groups on the surface. Then, the substrate with amino groups on the modified surface is immersed in a solution of Compound 9 at room temperature for the second condensation reaction to obtain a substrate loaded with Compound 9. The substrate loaded with Compound 9 is immersed in a malononitrile solution at room temperature for the third condensation reaction to obtain a substrate with a fluorescent probe loaded on the surface, which is the fluorescent material.

[0015] Furthermore, the molar ratio of Compound 3 to BBr3 is 1:3 - 5, and the demethylation reaction time is 4 h - 6 h; the molar ratio of Compound 5, ethyl 4-bromobutyrate, and potassium carbonate is 1:1.1 - 1.3:3 - 5, and the nucleophilic substitution reaction time is 6 h - 8 h; the molar ratio of Compound 6 to Compound b is 1:1.1 - 1.2, and the coupling reaction time is 8 h - 12 h; the acid used for hydrolysis is hydrochloric acid, and the concentration of hydrochloric acid is 11 M - 13 M; the molar ratio of Compound 8, the condensing agent, and N-hydroxysuccinimide is 1:2 - 3:2 - 3, the condensing agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and the esterification reaction time is 8 h - 12 h; the concentration of the Compound 9 solution is 95 μM - 105 μM, and the second condensation reaction time is 12 h - 24 h; the concentration of the malononitrile solution is 9.5 mM - 10.5 mM, and the third condensation reaction time is 1 h - 3 h.

[0016] Furthermore, the hydroxylation treatment and silanization treatment of the substrate include the following steps: The substrate is cleaned, and then the substrate is immersed in a 4% - 6% (mass concentration) γ-aminopropyltriethoxysilane solution at room temperature for 45 min - 60 min to obtain a substrate with amino groups on the surface. The substrate is glass.

[0017] Furthermore, the preparation method of Compound 3 includes the following steps: Using Compound 1 and POCl3 as raw materials, they are dissolved in the seventh solvent, and a formylation reaction is carried out at room temperature to obtain Compound 2; the synthesis reaction formula is as follows: .

[0018] Using Compound 2 and N-bromosuccinimide as raw materials, they are dissolved in the eighth solvent, and a substitution reaction is carried out at room temperature to obtain Compound 3; the synthesis reaction formula is as follows: .

[0019] Furthermore, the molar ratio of Compound 1 to POCl3 is 1:2.8 - 3.0. Before the formylation reaction, it is stirred at -1 °C - 1 °C for 1 h, and the formylation reaction time is 8 h - 12 h; the molar ratio of Compound 2 to N-bromosuccinimide is 1:1 - 1.1, and the substitution reaction time is 2 h - 4 h.

[0020] Further, a method for preparing compound b includes the following steps: Using compound a and isopropanol pinacol borate as raw materials, under the reaction system of n-butyllithium catalyst and the ninth solvent, a boration reaction is carried out at room temperature to obtain compound b; the molar ratio of compound a to isopropanol pinacol borate is 1:2 to 2.1, and the reaction time of the boration reaction is 10 h to 14 h; the synthesis reaction formula is as follows: .

[0021] The third object of the present invention is to provide the application of the above-mentioned dicyanoethylene fluorescent material in the preparation of a product for detecting biogenic amines.

[0022] The beneficial effects of the present invention are as follows: compared with the prior art: The fluorescent material based on dicyanoethylene provided by the present invention constructs a dicyanoethylene active group on the parent ring of a bisthienylamine derivative with fluorescent properties. When the fluorescent material contacts biogenic amines, due to the nucleophilic property of biogenic amines, a nucleophilic substitution reaction can occur with the probe molecule dicyanoethylene group to generate an imine chemical structure. And because the electron-withdrawing ability of dicyanoethylene is stronger than that of imine, the intramolecular charge transfer of the fluorescent material is significantly reduced, resulting in a blue shift of the molecular absorption and luminescence properties of the fluorescent material, emitting strong fluorescence and significant color changes. It can also accurately feedback the concentration of biogenic amines through fluorescence signal changes, enabling the glass-based ratio fluorescent material to solve the technical problem of inconvenient use of existing biogenic amine detection methods.

[0023] The fluorescent probe provided by the present invention, when R is hydrogen, forms a fluorescent material that can accurately identify and detect biogenic amines in solution, with high sensitivity and selectivity. Even in a complex solution system such as biological samples and food extracts, it can effectively reduce the interference of other substances and accurately feedback the concentration of biogenic amines through fluorescence signal changes, providing reliable quantitative analysis data for scenarios such as scientific research, clinical detection, or quality control, and helping to deeply study the behavior and role of biogenic amines in solution environments. Loading the structurally modified probe on a matrix with amino groups on the surface to form a fluorescent material can accurately identify and detect gaseous biogenic amines. Compared with the solution probe, its physical and chemical properties are more stable, and it can resist external environments such as humidity and slight vibration interference, making it suitable for detecting gaseous biogenic amines in complex environments. At the same time, this probe can be reused, reducing the single-use cost, and is convenient for carrying and on-site operation such as rapid detection in food markets and industrial sites, expanding the application scenarios, especially suitable for fields such as rapid food safety screening and environmental monitoring. Description of the Drawings

[0024] Figure 1 It is a synthetic route diagram of the fluorescent probe provided in Example 2 of the present invention loaded on glass with amino groups on the surface.

[0025] Figure 2 This is the fluorescence performance diagram of the fluorescent material EBTN1 for detecting n-octylamine in Example 1 of the present invention. Figure 2 In the figure (a), it is the absorption change diagram of EBTN1 caused by the addition of n-octylamine, and in the figure (b), it is the fluorescence change diagram of the EBTN1 solution with the continuous addition of n-octylamine.

[0026] Figure 3 This is the test diagram of the selectivity and anti-interference of the fluorescent material EBTN1 for detecting n-octylamine in Example 1 of the present invention. Figure 3 In the figure (a), it is the selectivity test diagram, and in the figure (b), it is the anti-interference test diagram.

[0027] Figure 4 This is the reaction mechanism of the detection of the fluorescent material EBTN1 in Example 1 of the present invention. Figure 4 In the figure (a), it is the reversible reaction of EBTN1 and primary amine, and in the figure (b), it is the HOMO-LUMO distribution and energy level diagram of EBTN1 and the recognition product EBTN-imine.

[0028] Figure 5 This is the detection performance diagram of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention for biogenic amines. Figure 5 In the figure (a), it is ordinary glass, in the figure (b), it is the absorption and emission spectra of 9-glass; in the figure (c), it is the absorption and emission spectra of the slide loaded with the probe, that is, EBTN1D-glass; in the figure (d), it is the absorption and emission spectra after the reaction of EBTN1D-glass with biogenic amines.

[0029] Figure 6 This is the cycle stability of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention for detecting biogenic amines. Detailed implementation manners

[0030] In order to enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the specific embodiments cited shall not be construed as limiting the present invention. The following test methods and detection methods are all conventional methods unless otherwise specified; the reagents and raw materials are all commercially available unless otherwise specified.

[0031] The present invention will be described in detail below through specific embodiments. The embodiments are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] A fluorescent material based on dicyanoethylene, the fluorescent material is a fluorescent probe, and the fluorescent probe has a chemical structural formula shown in Formula I: .

[0033] Among them, R is hydrogen or , is the connection site; When R is , the fluorescent probe is loaded on the matrix with amino groups on the surface.

[0034] The fluorescent material based on dicyanoethylene provided by the present invention constructs a dicyanoethylene active group on the parent ring of the bisthienylamine derivative with fluorescent properties. When the fluorescent material contacts with biogenic amines, due to the nucleophilic property of biogenic amines, a nucleophilic substitution reaction can occur with the dicyanoethylene group of the probe molecule to generate an imine chemical structure. And because the electron-withdrawing ability of dicyanoethylene is stronger than that of imine, the intramolecular charge transfer of the fluorescent material is severely reduced, resulting in a blue shift in the molecular absorption and luminescence properties of the fluorescent material, emitting strong fluorescence and significant color changes. It can also accurately feedback the concentration of biogenic amines through the change of fluorescence signal, enabling the glass-based ratio fluorescent material to solve the technical problem of inconvenient use of existing biogenic amine detection methods.

[0035] The fluorescent probe provided by the present invention, when R is hydrogen, forms a fluorescent material that can accurately identify and detect biogenic amines in solution, with high sensitivity and selectivity. Even in a complex solution system such as biological samples and food extracts, it can effectively reduce the interference of other substances and accurately feedback the concentration of biogenic amines through the change of fluorescence signal, providing reliable quantitative analysis data for scenarios such as scientific research, clinical detection, or quality control, and helping to deeply study the behavior and role of biogenic amines in the solution environment. Loading the structurally modified probe on the matrix with amino groups on the surface, the formed fluorescent material can accurately identify and detect gaseous biogenic amines. Compared with the solution probe, its physical and chemical properties are more stable, and it can resist external environments such as humidity and slight vibration interference, suitable for the detection of gaseous biogenic amines in complex environments. At the same time, this probe can be reused, reducing the cost per use, and is convenient for carrying and on-site operations such as rapid detection in food markets and industrial sites, expanding the application scenarios, especially suitable for fields such as rapid food safety screening and environmental monitoring.

[0036] The following is further illustrated by specific examples.

[0037] Example 1 This example provides a fluorescent material, and the specific preparation method is as follows: Step 1: Dissolve 0.50 g (1.75 mmol) of Compound 1 in 20 mL of anhydrous dichloromethane solution. Then add 280 μL (3.60 mmol) of anhydrous N,N-dimethylformamide to form a mixture. Cool the mixture to 0 °C in an ice bath. Then add 500 μL (5.10 mmol) of POCl3 dropwise to the mixture, stir at 0 °C for 1 h, and finally react at room temperature for 10 h.

[0038] After the reaction is completed, quench the reaction with 5 mL of 1 M sodium hydroxide to obtain a mixed solution. Wash the mixed solution successively with 100 mL of water and 100 mL of brine, then separate the organic phase. Dry the organic phase with anhydrous magnesium sulfate, filter out the desiccant, and finally purify by silica gel column chromatography using dichloromethane as the eluent to obtain 360 mg of Compound 2 with a yield of 66%. The synthetic reaction formula is as follows: 。

[0039] 1 H NMR (400 MHz, CDCl3, ppm) δ 9.88 (s, 1H), 7.73 (s, 1H), 7.50 (d, J = 8.8 Hz, 2H), 7.42 (d, J = 5.4 Hz, 1H), 7.15 - 7.04 (m, 3H), 3.92 (s, 3H). 13 C NMR(101 MHz, CDCl3, ppm) δ 183.0, 158.6, 148.6, 144.0, 140.6, 131.8, 128.8, 124.7, 124.4, 120.6, 116.3, 115.2, 111.9, 55.7. HR-MS (ESI-QTOF) m / z: C 16 H 12 NO2S2's [M + H] + The calculated value is 314.0309, and the found value is 314.0296.

[0040] Step 2: Dissolve 170 mg (0.54 mmol) of Compound 2 in 10 mL of tetrahydrofuran. Then add 103 mg (0.58 mmol) of N-bromosuccinimide to form a mixture. Stir the mixture at room temperature for 3 h for the reaction. After the reaction is completed, a reaction solution is formed.

[0041] 50 mL of dichloromethane and 50 mL of water were successively added to the reaction solution. The aqueous phase was separated, and the aqueous phase was further extracted three times with 50 mL of dichloromethane. The three extraction solutions were mixed, and then anhydrous magnesium sulfate as a desiccant was added to remove the residual water. The desiccant was filtered out, and finally evaporation was carried out under reduced pressure to obtain 200 mg of compound 3 with a yield of 94%. The synthetic reaction formula is as follows: .

[0042] 1 H NMR (400 MHz, DMSO - d 6 , ppm) δ 9.88 (s, 1H), 8.10 (s, 1H), 7.61 (d, J = 8.9 Hz, 2H), 7.47 (s, 1H), 7.16 (d, J = 8.9 Hz, 2H), 3.86 (s, 3H). 13 C NMR(101 MHz, DMSO - d 6 , ppm) δ 185.0, 158.7, 145.7, 142.7, 141.2, 131.1, 125.2, 123.6, 123.1, 116.6, 116.3, 116.2, 115.7, 56.0. HR - MS (ESI - QTOF) m / z: C 16 H 11 BrNO2S2's [M + H] + Calculated value is 391.9415, found value is 391.9409.

[0043] Step 3: Dissolve 1.00 g (molar amount: 2.13 mmol) of compound a in 10 mL of anhydrous tetrahydrofuran solution. Under the protection of an argon atmosphere, at -78 °C, a 2.5 M hexane solution containing 2.3 mmol of n - BuLi (n - butyllithium) was added to the above solution. After stirring for 1 h, 0.80 g (molar amount: 4.26 mmol) of isopropyl alcohol pinacol borate was added to form a reaction system. The reaction system was stirred at room temperature for 12 h. After the reaction was completed, 2 mL of water was added to quench the reaction, and a reaction solution was obtained.

[0044] The reaction solution was extracted three times with 15 mL of ethyl acetate each time for the organic phase. The three extracted organic phases were mixed, anhydrous magnesium sulfate as a desiccant was added to remove the residual water. After filtering out the desiccant, evaporation was carried out under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography with dichloromethane eluent to obtain 690 mg of compound b with a yield of 63%. The synthetic reaction formula is as follows:

[0045] 1 1H NMR (400 MHz, CDCl3, ppm) δ 7.62 (d, J = 8.5 Hz, 2H), 7.07 (d, J = 8.9 Hz, 4H), 6.89 (d, J = 8.5 Hz, 2H), 6.84 (d, J = 8.9 Hz, 4H), 3.96 (t, J = 6.5 Hz, 4H), 1.79 (m, 4H), 1.58 - 1.46 (m, 4H), 1.34 (s, 12H), 1.01 (t, J = 7.4 Hz, 6H). 13 13C NMR (101 MHz, CDCl3, ppm): δ 151.1, 146.7, 135.5, 131.0, 122.4, 114.6, 113.8, 110.5, 78.6, 63.2, 26.7, 20.1, 14.5, 9.2. HR-MS (ESI-QTOF) m / z: C 32 H 43 [M + H] of BO4 + Calculated value is 516.3285, found value is 582.3272.

[0046] Step 4: In a 50 mL tetrahydrofuran solution containing 900 mg of compound 3 with a molar amount of 2.29 mmol and 1.42 g of compound b with a molar amount of 2.75 mmol, add 132 mg of the transition metal catalyst Pd(PPh3)4 with a molar amount of 0.12 mmol and 15 mL of a 1 M Na2CO3 solution. Under an argon atmosphere, stir and reflux at 100 °C for 6 h to obtain a reaction solution.

[0047] Cool the reaction solution to room temperature, dilute it with 20 mL of dichloromethane, then filter through diatomaceous earth to remove the undissolved catalyst. Wash it three times with 150 mL of water each time, extract the organic phase, mix the organic phases extracted three times, add the drying agent anhydrous magnesium sulfate to remove residual moisture. After filtering out the drying agent, evaporate the organic solvent under reduced pressure to obtain a crude product. The crude product is purified by silica gel column chromatography, and the eluent used for purification is a mixture of petroleum ether and ethyl acetate with a volume ratio of 10:1, to obtain 960 mg of compound 4 with a yield of 60%. The synthetic reaction formula is as follows: .

[0048] 11H NMR (400 MHz, CDCl3, ppm) δ 9.85 (s, 1H), 7.69 (s, 1H), 7.52 (d, J = 8.9 Hz, 2H), 7.44 (d, J = 8.7 Hz, 2H), 7.12 (m, 7H), 6.93 (d, J = 8.7 Hz, 2H), 6.86 (d, J = 8.9 Hz, 4H), 3.97 (t, J = 6.5 Hz, 4H), 3.93 (s, 3H), 1.86 - 1.72 (m, 4H), 1.60 - 1.43 (m, 4H), 1.01 (t, J = 7.4 Hz, 6H). 13 13C NMR (101 MHz, CDCl3, ppm) δ 182.7, 158.6, 155.9, 149.2, 149.1, 148.5, 143.4, 140.1, 139.9, 131.8, 126.9, 126.4, 126.2, 125.0, 124.8, 120.2, 119.9, 115.4, 115.2, 114.4, 105.8, 68.0, 55.7, 31.4, 19.3, 13.9. HR-MS (ESI-QTOF) m / z: C 42 H 41 [M + H] of C18H14N2O4S2 + Calculated value is 701.2502, found value is 701.2497.

[0049] Step 5, Dissolve 100 mg (molar amount 0.14 mmol) of Compound 4 and 17 mg (molar amount 0.28 mmol) of malononitrile in 5 mL of N,N-dimethylformamide, stir at 100 °C for 30 min to obtain a mixture. Evaporate the mixture under reduced pressure, and then purify it by silica gel column chromatography. The eluent used for purification is a mixture of dichloromethane and petroleum ether with a volume ratio of 3:1. 100 mg of the fluorescent material is obtained, named EBTN1, yield: 93%. The synthetic reaction formula is as follows: .

[0050] 11H NMR (400 MHz, CDCl3, ppm) δ 7.67 (s, 1H), 7.62 (s, 1H), 7.47 (d, J = 8.9 Hz, 2H), 7.43 (d, J = 8.8 Hz, 2H), 7.17 - 7.06 (m, 7H), 6.92 (d, J = 8.8 Hz, 2H), 6.87 (d, J = 8.9 Hz, 4H), 3.97 (t, J = 6.5 Hz, 4H), 3.92 (s, 3H), 1.85 - 1.74 (m, 4H), 1.53 (m, 4H), 1.01 (t, J = 7.4 Hz, 6H). 13 13C NMR (101 MHz, CDCl3, ppm) δ 158.9, 156.1, 151.5, 151.4, 150.4, 149.6, 144.4, 139.8, 132.0, 131.1, 128.1, 127.1, 126.6, 125.5, 124.9, 119.5, 115.5, 115.4 (2C), 114.9, 114.4, 105.5, 71.0, 68.0, 55.7, 31.4, 19.3, 13.9. HR-MS (ESI-QTOF) m / z: C 45 H 40 for [M + H]+ of C + Calculated value is 748.2542, found value is 748.2524.

[0051] Example 2 This example provides a fluorescent material, and the specific preparation method is as follows: Step 1: Dissolve 0.50 g (1.75 mmol in molar amount) of Compound 1 in 20 mL of anhydrous dichloromethane solution, then add 280 μL (3.60 mmol in molar amount) of anhydrous N,N-dimethylformamide to form a mixture. The mixture is cooled to 0 °C in an ice bath, and then 500 μL (5.10 mmol in molar amount) of POCl3 is added dropwise to the mixture. Stir at 0 °C for 1 h and finally overnight at room temperature.

[0052] After the reaction is completed, quench the reaction with 5 mL of 1 M sodium hydroxide to obtain a mixed solution. The mixed solution is washed successively with 100 mL of water and 100 mL of brine, then the organic phase is separated. The organic phase is dried with anhydrous magnesium sulfate, the desiccant is filtered out, and finally silica gel column chromatography purification is carried out with dichloromethane as the eluent to obtain 360 mg of Compound 2, with a yield of 66%. The synthesis reaction formula is as follows: 。

[0053] 1 1H NMR (400 MHz, CDCl3, ppm) δ 9.88 (s, 1H), 7.73 (s, 1H), 7.50 (d, J J = 8.8 Hz, 2H), 7.42 (d, J J = 5.4 Hz, 1H), 7.15 - 7.04 (m, 3H), 3.92 (s, 3H). 13 13C NMR(101 MHz, CDCl3, ppm) δ 183.0, 158.6, 148.6, 144.0, 140.6, 131.8, 128.8, 124.7, 124.4, 120.6, 116.3, 115.2, 111.9, 55.7. HR-MS (ESI-QTOF) m / z: C 16 H 12 NO2S2 of [M + H] + Calculated value is 314.0309, found value is 314.0296.

[0054] Step 2: Dissolve 170 mg (molar amount 0.54 mmol) of Compound 2 in 10 mL of tetrahydrofuran, then add 103 mg (molar amount 0.58 mmol) of N-bromosuccinimide to form a mixture. Stir the mixture at room temperature for 3 h for reaction. After the reaction, a reaction solution is formed.

[0055] Add 50 mL of dichloromethane and 50 mL of water to the reaction solution in sequence. Separate the aqueous phase. The aqueous phase is further extracted three times with 50 mL of dichloromethane each time. Mix the three extraction solutions, then add anhydrous magnesium sulfate as a drying agent to remove residual moisture. Filter out the drying agent, and finally perform evaporation under reduced pressure to obtain 200 mg of Compound 3 with a yield of 94%. The synthetic reaction formula is as follows: 。

[0056] 1 1H NMR (400 MHz, DMSO-d 6 , ppm) δ 9.88 (s, 1H), 8.10 (s, 1H), 7.61 (d, J = 8.9 Hz, 2H), 7.47 (s, 1H), 7.16 (d, J = 8.9 Hz, 2H), 3.86 (s, 3H). 13 13C NMR(101 MHz, DMSO-d 6, ppm) δ 185.0, 158.7, 145.7, 142.7, 141.2, 131.1, 125.2, 123.6, 123.1, 116.6, 116.3, 116.2, 115.7, 56.0. HR-MS (ESI-QTOF) m / z: C 16 H 11 [M + H] of BrNO2S2 + Calculated value is 391.9415, found value is 391.9409.

[0057] Step 3: Dissolve 1.00 g (molar amount 2.13 mmol) of compound a in 10 mL of anhydrous tetrahydrofuran solution. Under the protection of an argon atmosphere, add a 2.5 M hexane solution containing 2.3 mmol of n-butyllithium (n-BuLi) to the above solution at -78 °C. After stirring for 1 h, add 0.80 g (molar amount 4.26 mmol) of isopropyl alcohol pinacol borate to form a reaction system. Stir the reaction system at room temperature for 12 h. After the reaction is completed, add 2 mL of water to quench the reaction to obtain a reaction solution.

[0058] Extract the reaction solution three times with 15 mL of ethyl acetate each time. Mix the organic phases extracted three times, add anhydrous magnesium sulfate as a drying agent to remove residual moisture. After filtering out the drying agent, evaporate under reduced pressure to obtain a crude product. The crude product is purified by silica gel column chromatography with dichloromethane eluent to obtain 690 mg of compound b, with a yield of 63%. The synthetic reaction formula is as follows: .

[0059] 1 H NMR (400 MHz, CDCl3, ppm) δ 7.62 (d, J = 8.5 Hz, 2H), 7.07 (d, J = 8.9 Hz, 4H), 6.89 (d, J = 8.5 Hz, 2H), 6.84 (d, J = 8.9 Hz, 4H), 3.96 (t, J = 6.5 Hz, 4H), 1.79 (m, 4H), 1.58 - 1.46 (m, 4H), 1.34 (s, 12H), 1.01 (t, J = 7.4 Hz, 6H). 1313C NMR (101 MHz, CDCl3, ppm): δ 151.1, 146.7, 135.5, 131.0, 122.4, 114.6, 113.8, 110.5, 78.6, 63.2, 26.7, 20.1, 14.5, 9.2. HR-MS (ESI-QTOF) m / z: C 32 H 43 [M + H]+ of C 32 H 43 BO4 + Calculated value is 516.3285, found value is 582.3272.

[0060] Step 4, under an argon atmosphere, 10.2 mL of a dichloromethane solution of 1 M BBr3 with a molar amount of 10.2 mmol was added dropwise to 200 mL of an anhydrous dichloromethane solution containing 1.0 g of compound 3 with a molar amount of 2.55 mmol at 0 °C. After stirring at room temperature for 6 h at 100 °C, 10 mL of water was added to quench the reaction to form a mixed solution.

[0061] The mixed solution was filtered to obtain a solid and a filtrate. The separated solid was washed with 250 mL of 1 M hydrochloric acid to obtain a washing solution. The washing solution was extracted with 200 mL of dichloromethane. The separated organic phase was added to the filtrate to form a mixed solution. The mixed solution was washed with 100 mL of water. The organic phase was separated, and anhydrous magnesium sulfate was added as a drying agent to remove residual moisture. After filtering out the drying agent, the organic solvent was evaporated under reduced pressure to obtain an oily crude product. The crude product was purified by silica gel column chromatography. The eluent used for purification was a mixture of dichloromethane and ethyl acetate with a volume ratio of 10:1, and 895 mg of compound 5 was obtained with a yield of 93%. The synthetic reaction formula is shown as follows: .

[0062] 1 1H NMR (400 MHz, DMSO-d 6 , ppm) δ 9.88 (s, 1H), 9.83 (s, 1H), 8.11 (s, 1H), 7.49 (d, J = 8.8 Hz, 2H), 7.46 (s, 1H), 6.98 (d, J = 8.8 Hz, 2H). 13 13C NMR(101 MHz, DMSO-d 6 , ppm) δ 185.0, 157.2, 145.8, 142.8, 141.2, 129.6, 125.2, 123.4, 116.9, 116.3, 116.2, 116.2. HR-MS (ESI-QTOF) m / z: C15 The [M+H] of H9BrNO2S2 + The calculated value is 377.9258, and the found value is 377.9252.

[0063] Step 5: Dissolve 960 mg (2.55 mmol) of Compound 5 and 1.1 g (7.65 mmol) of K2CO3 in 250 mL of N,N-dimethylformamide, then add dropwise 0.60 g (3.06 mmol) of ethyl 4-bromobutyrate to form a mixture. Stir the mixture at 60 °C for 8 h to obtain a reaction solution.

[0064] Perform vacuum evaporation on the reaction solution to remove most of the N,N-dimethylformamide to form a concentrate. Add 50 mL of ethyl acetate to the concentrate to redissolve it, then add 150 mL of water for washing. Separate the aqueous phase and the filtrate. Then extract the aqueous phase with 150 mL of ethyl acetate twice. Combine the two extraction solutions to obtain an organic phase. Mix the organic phase and the filtrate, wash with 100 mL of water, separate the organic phase, add anhydrous magnesium sulfate as a drying agent to remove residual moisture, filter to remove the drying agent, and finally perform evaporation under reduced pressure to obtain a crude product. Purify the crude product by silica gel column chromatography using dichloromethane as the eluent to obtain 1.20 g of Compound 6 with a yield of 96%. The synthetic reaction formula is as follows: 。

[0065] 1 H NMR (400 MHz, CDCl3, ppm) δ 9.87 (s, 1H), 7.69 (s, 1H), 7.44 (d, J = 8.9 Hz, 2H), 7.15 (s, 1H), 7.08 (d, J = 8.9 Hz, 2H), 4.20 (q, J = 7.1 Hz, 2H), 4.12 (t, J = 6.1 Hz, 2H), 2.58 (t, J = 7.2 Hz, 2H), 2.27 – 2.13 (m, 2H), 1.31 (t, J = 7.1 Hz, 3H). 13 C NMR (101 MHz, CDCl3, ppm) δ 183.0, 173.1, 158.1, 146.1, 143.0, 140.9, 131.3, 124.8, 124.0, 120.4, 116.2, 115.8, 115.2, 67.3, 60.6, 30.7, 24.6, 14.3. HR-MS (ESI-QTOF) m / z: C 21 H19 [M+H] of BrNO4S2 + The calculated value is 491.9933, and the found value is 491.9935.

[0066] Step 6: Under an argon atmosphere, into a 2 mL tetrahydrofuran solution containing 38 mg (molar amount 0.07 mmol) of compound b and 30 mg (molar amount 0.06 mmol) of compound 6, add 0.2 mL of a 1 M K2CO3 solution containing 35 mg (molar amount 0.03 mmol) of the catalyst Pd(PPh3)4. Stir and reflux the reaction at 100 °C for 8 h, then cool the mixture to room temperature to obtain a reaction solution.

[0067] Add 20 mL of dichloromethane to the reaction solution for dilution, filter through diatomaceous earth to remove the undissolved catalyst to obtain a filtrate, wash the filtrate with 150 mL of water, and separate to obtain the organic phase. Add anhydrous magnesium sulfate as a desiccant to the organic phase to remove residual moisture, filter out the desiccant, and finally evaporate under reduced pressure to obtain the crude product. The crude product is purified by silica gel column chromatography, and the eluent used is dichloromethane and petroleum ether with a volume ratio of 1:1 to obtain 45 mg of compound 7, with a yield of 76%. The synthetic reaction formula is as follows: 。

[0068] 1 H NMR (400 MHz, CDCl3, ppm) δ 9.81 (s, 1H), 7.65 (s, 1H), 7.48 (d, J = 8.9 Hz, 2H), 7.42 (d, J = 8.8 Hz, 2H), 7.14 (s, 1H), 7.08 (d, J = 8.9 Hz, 6H), 6.92 (d, J = 8.8 Hz, 2H), 6.86 (d, J = 8.9 Hz, 4H), 4.20 (q, J = 7.1 Hz, 2H), 4.12 (t, J = 6.1 Hz, 2H), 3.97 (t, J = 6.5 Hz, 4H), 2.59 (t, J = 7.2 Hz, 2H), 2.28 - 2.13 (m, 2H), 1.79 (m, 4H), 1.60 - 1.45 (m, 4H), 1.31 (t, J = 7.1 Hz, 3H), 1.01 (t, J = 7.4 Hz, 6H). 1313C NMR (101 MHz, CDCl3, ppm) δ 182.7, 173.1, 157.8, 155.9, 149.2, 149.1, 148.5, 143.3, 140.1, 139.9, 131.8, 126.9, 126.4, 126.2, 125.0, 124.8, 120.3, 119.8, 115.7, 115.4, 114.4, 105.8, 68.0, 67.2, 60.5, 31.4, 30.8, 24.6, 19.3, 14.3, 13.9. HR-MS (ESI-QTOF) m / z: C 47 H 48 [M + H] of C + Calculated value for C

[0069] Step 7: Add 3 mL of 12 M hydrochloric acid to a 12 mL tetrahydrofuran solution containing 80 mg (molar amount: 1.00 mmol) of Compound 7, stir overnight at room temperature to obtain a reaction solution.

[0070] Extract the reaction solution three times with 50 mL of dichloromethane each time. Combine the extracts from the three extractions, add 100 mL of water to the resulting organic phase for washing, and separate the organic phase. Add anhydrous magnesium sulfate as a drying agent to the organic phase to remove residual moisture, filter out the drying agent, and finally evaporate under reduced pressure to obtain a crude product. Purify the crude product by silica column chromatography using an eluent of dichloromethane and ethyl acetate with a volume ratio of 2:3 to obtain 76 mg of Compound 8 with a yield of 97%. The synthetic reaction formula is as follows: .

[0071] 11H NMR (400 MHz, CDCl3, ppm) δ 9.83 (s, 1H), 7.67 (s, 1H), 7.48 (d, J = 8.9 Hz, 2H), 7.43 (d, J = 8.8 Hz, 2H), 7.15 (s, 1H), 7.08 (d, J = 8.9 Hz, 6H), 6.92 (d, J = 8.9 Hz, 2H), 6.86 (d, J = 8.9 Hz, 4H), 4.14 (t, J = 6.0 Hz, 2H), 3.97 (t, J = 6.4 Hz, 4H), 2.67 (t, J = 7.2 Hz, 2H), 2.22 (m, 2H), 1.79 (m, 4H), 1.52 (m, 4H), 1.01 (t, J = 7.4 Hz, 6H). 13 13C NMR (101 MHz, CDCl3, ppm) δ 182.8, 177.3, 157.7, 155.9, 149.2, 149.1, 148.5, 143.3, 140.1, 139.9, 131.9, 126.9, 126.4, 126.1, 125.1, 124.2, 120.2, 119.8, 115.7, 115.4, 114.4, 105.8, 68.0, 67.0, 31.4, 30.2, 24.4, 19.3, 13.9. HR-MS (ESI-QTOF) m / z: C 45 H 45 [M + H] of C + Calculated value is 773.2714, found value is 772.2683.

[0072] Step 8, under an argon atmosphere, 23 mg (0.20 mmol in molar amount) of N-hydroxysuccinimide and 38 mg (0.20 mmol in molar amount) of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to a 5 mL anhydrous N,N-dimethylformamide solution containing 77 mg (0.10 mmol in molar amount) of Compound 8. After stirring at room temperature for 8 h, a reaction solution was obtained.

[0073] 50 mL of dichloromethane was added to the reaction solution, and then it was washed successively with 50 mL of saturated NaHCO3 solution and 100 mL of water. The organic phase was separated, and anhydrous magnesium sulfate as a desiccant was added to the organic phase to remove residual moisture. After filtering out the desiccant, finally, evaporation was carried out under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography. The eluent used for purification was a mixture of dichloromethane and petroleum ether with a volume ratio of 1:1, and 71 mg of compound 9 was obtained with a yield of 82%. The synthetic reaction formula is shown as follows: 。

[0074] 1 1H NMR (400 MHz, CDCl3, ppm) δ 9.84 (s, 1H), 7.69 (s, 1H), 7.51 (d, J = 8.9 Hz, 2H), 7.44 (d, J = 8.8 Hz, 2H), 7.17 (s, 1H), 7.12 (d, J = 8.9 Hz, 2H), 7.09 (d, J = 9.0 Hz, 4H), 6.92 (d, J = 8.9 Hz, 2H), 6.86 (d, J = 9.0 Hz, 4H), 4.19 (t, J = 6.0 Hz, 2H), 3.97 (t, J = 6.4 Hz, 4H), 2.91 (m, 6H), 2.32 (m, 2H), 1.79 (m, 4H), 1.52 (m, 4H), 1.01 (t, J = 7.4 Hz, 6H). 13 13C NMR (101 MHz, CDCl3, ppm) δ 182.7, 169.1, 168.3, 157.6, 155.9, 149.2, 149.1, 148.5, 143.3, 140.1, 139.9, 132.0, 126.9, 126.4, 126.2, 125.0, 124.8, 120.3, 119.9, 115.8, 115.3, 114.4, 105.8, 68.0, 66.4, 31.4, 27.8, 25.6, 24.4, 19.3, 13.9. HR-MS (ESI-QTOF) m / z: C 42 H 41 N2O4S2 of [M + H] + Calculated value was 870.2877, found value was 870.2892.

[0075] Step 10, as Figure 1As shown, using glass as the substrate, the glass surface is successively cleaned with detergent, water, acetone, and methanol, and each cleaning step requires ultrasonic treatment for 15 min to obtain clean glass; the glass is immersed in a methanol solution containing 5% APTES by mass fraction and left standing at room temperature for 50 min. Then the glass is washed with methanol and dried at 120 °C for 30 min to obtain silanized glass.

[0076] Step 11, at room temperature, the glass obtained in Step 10 is immersed in a methanol solution containing 100 μM compound 9 for 12 h, then rinsed with methanol and air-dried to obtain glass loaded with compound 9, named 9-glass; then at room temperature, 9-glass is immersed in a 10 mM malononitrile solution for 2 h. Finally, the glass is rinsed with methanol to obtain a solid substrate loaded with a fluorescent probe, which is a fluorescent material named EBTN1D-glass.

[0077] Using the fluorescent material EBTN1 prepared in Example 1 to detect biogenic amines, including the following steps: Dissolve 1.87 mg of EBTN1 in dimethyl sulfoxide and make up to the mark in a 5 mL volumetric flask to obtain an EBTN1 stock solution with a concentration of 2.5 μM.

[0078] Dissolve 8.2 μL of n-octylamine in dimethyl sulfoxide and make up to the mark in a 50 mL volumetric flask to form an n-octylamine stock solution with a concentration of 1.0 mM.

[0079] Add 20 μL of the EBTN1 stock solution to 11 5 mL volumetric flasks respectively. Then, add different volumes of n-octylamine solution increasing by 50 μL to each volumetric flask, dilute to the mark of the volumetric flask with dimethyl sulfoxide, and store in the dark for 14 h. Finally, measure the ultraviolet / visible spectrum and fluorescence spectrum.

[0080] Figure 2 This is the fluorescence performance diagram of the fluorescent material EBTN1 for detecting n-octylamine in Example 1 of the present invention. Figure 2 In figure (a), it is the absorption change diagram of EBTN1 caused by the addition of n-octylamine, and in figure (b), it is the fluorescence change diagram of the EBTN1 solution with the continuous addition of n-octylamine. As Figure 2As shown in Figure (a) therein, with the increase in the concentration of n-octylamine, the characteristic intramolecular charge transfer absorption band at 530 nm continuously weakens, accompanied by the fading of the purple color of the dye solution. At the same time, a new peak appears at 410 nm. The existence of an isosbestic point at 460 nm indicates that a single chemical reaction has occurred. And through kinetic analysis, the reaction order of EBTN1 with biogenic amines is first-order. With the addition of amines, a new emission peak appears at 556 nm and steadily increases. At a high concentration of 10 μM, the probe reacts rapidly with amines, and the change in fluorescence can be observed immediately. The quantum yield of the newly formed product is 0.75. Since EBTN1 itself has very weak luminescence properties in DMSO, a significant fluorescence "turn-on" response is achieved, and the fluorescence enhancement factor is 112 times. As Figure 2 shown in Figure (b) therein. For a dye concentration of 5 μM, the theoretical detection limit of n-octylamine is as low as 160 nM. Moreover, the transformation process from the dicyanovinyl form to the imine form is accompanied by an obvious color change, which can be attributed to the reduction of the intramolecular charge transfer characteristics.

[0081] After adding different nucleophiles, the selectivity of EBTN1 for primary amines was evaluated by monitoring the fluorescence change at 556 nm. The nucleophiles include primary amines: putrescine, tyramine, cadaverine, octylamine, propylamine, histamine, tryptamine, spermidine, 1,3-propanediamine, secondary amines: diethylamine, diisopropylamine, tertiary amines: triethylamine, aromatic amines: pyridine, aniline, and thiols: ethanethiol.

[0082] Figure 3 This is the test chart for the selectivity and anti-interference of the fluorescent material EBTN1 for the detection of n-octylamine in Example 1 of the present invention. Figure 3 Figure (a) therein is the selectivity test chart, and Figure (b) is the anti-interference test chart. As Figure 3 shown, all primary amines cause the fluorescence of EBTN1 to increase. In contrast, under the given conditions, none of the secondary amines such as diethylamine and diisopropylamine, tertiary amines such as triethylamine, aromatic amines such as pyridine and aniline, and thiols such as ethanethiol show this fluorescence increase. Subsequently, when n-octylamine was added to these non-reactive mixtures, a strong fluorescence and a significant color change were immediately observed. This result emphasizes the selectivity of EBTN1 for primary amines and indicates that there is no interference from other analytes.

[0083] Figure 4 This is the reaction mechanism for the detection of the fluorescent material EBTN1 in Example 1 of the present invention. Figure 4 Figure (a) therein is the reversible reaction of EBTN1 and primary amines, and Figure (b) is the HOMO-LUMO distribution and energy levels of EBTN1 and EBTN-imine. The △E in Figure (b) corresponds to the energy difference calculated by TD-DFT. As Figure 4As shown in (a), when converting from dicyanoethylene to imine, the significant color change observed can clearly be explained as a reduction in intramolecular charge transfer. As Figure 4 As shown in (b), this was confirmed by DFT calculations of EBTN1 and EBTN-imine. The highest occupied molecular orbitals (HOMOs) of both molecules are distributed across the entire conjugated backbone, while the lowest unoccupied molecular orbitals (LUMOs) are mainly distributed on the acceptor, indicating the presence of a molecular charge transfer process. Apparently, the electron-withdrawing ability of the imine group is weaker, and the LUMO and HOMO energy levels increase. Therefore, the energy level difference (ΔE) of EBTN-imine increases compared to EBTN1, from 2.24 eV to 3.04 eV, showing a blue shift behavior in the spectrum.

[0084] The fluorescent material EBTN1D-glass prepared in Example 2 is used for detecting biogenic amines, including the following steps: Figure 5 This is the performance graph of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention for detecting biogenic amines. Figure 5 In (a) of is ordinary glass, and in (b) are the absorption and emission spectra of 9-glass; in (c) are the absorption and emission spectra of EBTN1D-glass; in (d) are the absorption and emission spectra of EBTN1D-glass after reacting with biogenic amines. As Figure 5 As shown in (a) to (b) of, in order to achieve cyclic detection of biogenic amine gas by the probe, compound 9 was covalently grafted onto the glass surface. The absorption and emission peaks that appeared at 430 nm and 555 nm for 9-glass indicate that 9 was successfully modified on the glass surface. Figure 5 As shown in (c) of, after soaking 9-glass in malononitrile solution, the glass slide turned red, and at the same time, it was detected that the absorption and emission peaks of the glass material were red-shifted to 542 nm and 660 nm respectively, indicating that 9-glass was converted into the fluorescent material EBTN1D-glass. When the fluorescent material EBTN1D-glass was placed in saturated n-propylamine vapor for 5 min, the absorption band at 542 nm was blue-shifted to 420 nm, and a corresponding new fluorescence peak appeared at 523 nm, proving that the fluorescent material EBTN1D-glass can perform ratio-type fluorescence response to primary amine gas. Due to the strong emission characteristics of the imine structure, in an n-propylamine atmosphere, the fluorescent material EBTN1D-glass shows bright blue fluorescence. Figure 5 As shown in (d) to (c) of, after reacting EBTN1D-glass with biogenic amines and then immersing it in malononitrile solution, the fluorescent material EBTN1D-glass restored its initial absorption and fluorescence emission spectra, proving its regenerability and the recyclability of EBTN1D-glass for detecting primary amine gas.

[0085] Figure 6The cycle stability of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention for the detection of biogenic amines. As Figure 6 shown, after 6 cycles, the fluorescence emission decay of EBTN1D-glass is less than 90%, indicating that the device has good sensing stability.

[0086] The above description only refers to the preferred embodiments of the present invention, and the above specific embodiments are not limitations on the present invention. Within the scope of the technical idea of the present invention, various deformations and modifications can occur. Any retouching, modification or equivalent replacement made by those of ordinary skill in the art according to the above description shall fall within the scope protected by the present invention.

Claims

1. A dicyanoethylene-based fluorescent material, characterized in that, The fluorescent material is a fluorescent probe, and the fluorescent probe has a chemical structural formula as shown in Formula I: ； wherein, R is hydrogen or , is a linking site; When R is the fluorescent probe is loaded on a matrix with an amino group on its surface.

2. The preparation method of the dicyanoethylene-based fluorescent material according to claim 1, wherein When R is hydrogen, the preparation method comprises the following steps: Using compound b and compound 3 as raw materials, in a reaction system of a transition metal catalyst, a base and a first solvent, under a protective gas atmosphere, a coupling reaction is carried out at 100 °C to 110 °C to obtain compound 4; the synthesis reaction formula is as follows: ； Using compound 4 and malononitrile as raw materials, in a second solvent reaction system, a first condensation reaction is carried out at 100 °C to 110 °C to obtain the fluorescent probe, which is the fluorescent material, and the synthesis reaction formula is as follows: 。 3. The preparation method of the dicyanoethylene-based fluorescent material according to claim 2, characterized in that, The molar ratio of compound 3 to compound b is 1:1.1 to 1.3, and the time of the substitution reaction is 5.5 h to 6.5 h; the molar ratio of compound 4 to malononitrile is 1:2.0 to 3.0, and the time of the first condensation reaction is 30 min to 60 min.

4. The preparation method of the dicyanoethylene-based fluorescent probe according to claim 1, characterized in that, When R is the preparation method of the fluorescent probe comprises the following steps: Using compound 3 and BBr3 as raw materials, in a third solvent reaction system, a demethylation reaction is carried out at room temperature under a protective gas atmosphere to obtain compound 5; the synthesis reaction formula is as follows: ； Using compound 5, ethyl 4-bromobutyrate and potassium carbonate as raw materials, in a fourth solvent reaction system, a nucleophilic substitution reaction is carried out at 55 °C to 65 °C to obtain compound 6; the synthesis reaction formula is as follows: ； Using compound 6 and compound b as raw materials, in a reaction system of a transition metal catalyst, potassium carbonate and a fifth solvent, under a protective gas atmosphere, a coupling reaction is carried out at 100 °C to 110 °C to obtain compound 7; the synthesis reaction formula is as follows: ； Under acidic conditions, compound 7 is hydrolyzed at room temperature to obtain compound 8; the synthesis reaction formula is as follows: ； Using compound 8 and N-hydroxysuccinimide as raw materials, in a reaction system of a sixth solvent and a condensing agent, an esterification reaction is carried out at room temperature to obtain compound 9; the synthesis reaction formula is as follows: ； The substrate is subjected to silanization treatment to obtain a substrate with an amino group on the surface, and then the amino-modified substrate is immersed in a solution of compound 9 at room temperature for a second condensation reaction to obtain a substrate loaded with compound 9. The substrate loaded with compound 9 is immersed in a solution of malononitrile at room temperature for a third condensation reaction to obtain a substrate with a fluorescent probe loaded on the surface, which is the fluorescent material.

5. The preparation method of the dicyanoethylene-based fluorescent material according to claim 4, wherein The molar ratio of compound 3 to BBr3 is 1:3 to 5, and the time of the demethylation reaction is 4 h to 6 h; The molar ratio of compound 5, ethyl 4-bromobutyrate and potassium carbonate is 1:1.1 to 1.3:3 to 5, and the time of the nucleophilic substitution reaction is 6 h to 8 h; The molar ratio of compound 6 to compound b is 1:1.1 to 1.2, and the time of the coupling reaction is 8 h to 12 h; The acid used for hydrolysis is hydrochloric acid, and the concentration of hydrochloric acid is 11 M to 13 M; The molar ratio of compound 8, the condensing agent and N-hydroxysuccinimide is 1:2 to 3:2 to 3, the condensing agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and the time of the esterification reaction is 8 h to 12 h; The concentration of the solution of compound 9 is 95 μM to 105 μM, and the time of the second condensation reaction is 12 h to 24 h; The concentration of the malononitrile solution is 9.5 mM to 10.5 mM, and the time of the third condensation reaction is 1 h to 3 h.

6. The preparation method of the dicyanoethylene-based fluorescent material according to claim 4, wherein, The substrate is subjected to silanization treatment, including the following steps: The substrate is cleaned, and then the substrate is soaked at room temperature in a γ-aminopropyltriethoxysilane solution with a mass concentration of 4% to 6% for 45 min to 60 min to obtain a substrate with an amino group-modified surface. The substrate is glass.

7. The preparation method of the dicyanoethylene-based fluorescent material according to claim 2 or claim 4, characterized in that, A preparation method of compound 3, including the following steps: Using compound 1 and POCl3 as raw materials, dissolving them in a seventh solvent, and performing a formylation reaction at room temperature to obtain compound 2; the synthesis reaction formula is as follows: ； Using compound 2 and N-bromosuccinimide as raw materials, dissolving them in an eighth solvent, and performing a substitution reaction at room temperature to obtain compound 3; the synthesis reaction formula is as follows: 。 8. The preparation method of the dicyanoethylene-based fluorescent material according to claim 7, wherein The molar ratio of compound 1 to POCl3 is 1:2.8 to 3.

0. Before the formylation reaction, it is stirred at -1°C to 1°C for 1 h, and the time of the formylation reaction is 8 h to 12 h; the molar ratio of compound 2 to N-bromosuccinimide is 1:1 to 1.1, and the time of the substitution reaction is 2 h to 4 h.

9. The preparation method of the dicyanoethylene-based fluorescent material according to claim 2 or claim 4, characterized in that, A preparation method of compound b, including the following steps: Using compound a and isopropyl alcohol pinacol borate as raw materials, in a reaction system of n-butyllithium catalyst and a ninth solvent, performing a boration reaction at room temperature to obtain compound b; the molar ratio of compound a to isopropyl alcohol pinacol borate is 1:2 to 2.1, and the time of the boration reaction is 10 h to 14 h; the synthesis reaction formula is as follows: 。 10. Use of the fluorescent material based on dicyanoethylene described in claim 1 in the preparation of a product for detecting biogenic amines.

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