A fluorescent material based on dicyanoethylene and its preparation method and application

Abstract

The present invention relates to the technical field of biogenic amine detection, and more specifically to a dicyanoethylene-based fluorescent material, its preparation method, and its application. After the biogenic amine comes into contact with a fluorescent probe on a glass surface, due to the nucleophilic properties of the biogenic amine, it can undergo a nucleophilic substitution reaction with the dicyanoethylene group of the probe molecule, generating an imine chemical structure. Because the electron-withdrawing ability of dicyanoethylene is stronger than that of the imine, the intramolecular charge transfer effect of the probe molecule is drastically reduced, resulting in a blue shift in the absorption and luminescence properties of the probe molecule. After the fluorescent probe is loaded onto the glass surface, the resulting dicyanoethylene-based fluorescent material provides a solution to the technical problems of the inconvenience of existing biogenic amine detection methods.

Description

Technical Field

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

[0002] Meat and its products are an important part of the human daily diet, and their freshness and safety are of paramount importance. However, due to inevitable microbial activity, meat is prone to spoilage during storage and produces a series of toxic and harmful substances during storage and transportation. Among them, biogenic amines are one of the key indicators causing food spoilage. These biogenic amines gradually accumulate during the deterioration of meat, which not only affects the taste and nutritional value of the food, but more importantly, the intake of high concentrations of biogenic amines can trigger a series of adverse reactions such as headaches, hypotension or hypertension, nausea, palpitations, 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 issue in the field of food safety.

[0003] Currently, chromatography, capillary electrophoresis, and electrochemical techniques are the main methods for biogenic amine detection. However, these methods have limitations such as complex sample pretreatment, expensive equipment, time-consuming operation, and the need for skilled personnel, which severely restricts their widespread 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 dicyanoethylene-based fluorescent material and a preparation method and application thereof, thereby solving the technical problem that the existing biogenic amine detection method is inconvenient to use.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The first object of the present invention is to provide a dicyanoethylene-based fluorescent material, wherein the fluorescent material is a fluorescent probe having a chemical structure as shown in Formula I:

[0007] ;

[0008] Wherein, R is hydrogen or , is the connection site;

[0009] When R is When the fluorescent probe is loaded on a substrate having amino groups on the surface.

[0010] A second object of the present invention is to provide a method for preparing the above-mentioned dicyanoethylene-based fluorescent material, when R is hydrogen, the preparation method comprises the following steps:

[0011] Compound b and compound 3 are used as raw materials, and a coupling reaction is carried out in a transition metal catalyst, a base and a first solvent reaction system at 100°C to 110°C under a protective gas atmosphere to obtain compound 4; the synthetic reaction formula is shown below:

[0012] .

[0013] Using compound 4 and malononitrile as raw materials, a first condensation reaction is carried out in a second solvent reaction system at 100°C to 110°C to obtain a fluorescent probe, i.e., a fluorescent material. The synthetic reaction formula is shown below:

[0014] .

[0015] Furthermore, the molar ratio of compound 3 to compound b is 1:1.1-1.3, and the substitution reaction time is 5.5h-6.5h; the molar ratio of compound 4 to malononitrile is 1:2.0-3.0, and the first condensation reaction time is 30min-60min.

[0016] Furthermore, when R is When the fluorescent probe is prepared, the method comprises the following steps:

[0017] Compound 3 and BBr3 were used as raw materials, and a demethylation reaction was carried out in a third solvent reaction system at room temperature under a protective gas atmosphere to obtain compound 5; the synthetic reaction formula is shown below:

[0018] .

[0019] Compound 5, ethyl 4-bromobutyrate and potassium carbonate are used as raw materials, and a nucleophilic substitution reaction is carried out in a fourth solvent reaction system at 55°C to 65°C to obtain compound 6. The synthetic reaction formula is shown below:

[0020] .

[0021] Compound 6 and compound b are used as raw materials, and a coupling reaction is carried out in a transition metal catalyst, potassium carbonate and a fifth solvent reaction system at 100°C to 110°C under a protective gas atmosphere to obtain compound 7. The synthetic reaction formula is shown below:

[0022] .

[0023] Under acidic conditions, compound 7 was hydrolyzed at room temperature to obtain compound 8; the synthetic reaction formula is shown below:

[0024] .

[0025] Compound 8 and N-hydroxysuccinimide are used as raw materials, and an esterification reaction is carried out in a sixth solvent and a condensing agent reaction system at room temperature to obtain compound 9; the synthetic reaction formula is shown below:

[0026] .

[0027] The substrate is subjected to silanization treatment to obtain a substrate with amino groups modified on the surface. The substrate with amino groups modified on the surface is then immersed in a solution of compound 9 at room temperature to carry out a 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 to carry out a third condensation reaction to obtain a substrate with a fluorescent probe loaded on the surface, which is a fluorescent material.

[0028] Furthermore, the molar ratio of compound 3 and BBr3 is 1:3-5, and the demethylation reaction time is 4h-6h; 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 6h-8h; the molar ratio of compound 6 and compound b is 1:1.1-1.2, and the coupling reaction time is 8h-12h; the acid used for hydrolysis is hydrochloric acid, and the concentration of hydrochloric acid is 11M-13M; The molar ratio of compound 8, 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 8h~12h; the concentration of compound 9 solution is 95μM~105μM, and the second condensation reaction time is 12h~24h; the concentration of malononitrile solution is 9.5mM~10.5mM, and the third condensation reaction time is 1h~3h.

[0029] Furthermore, the substrate is subjected to hydroxylation and silanization treatment, comprising the following steps:

[0030] The substrate is cleaned, and then immersed in a γ-aminopropyltriethoxysilane solution with a mass concentration of 4% to 6% for 45 minutes to 60 minutes at room temperature to obtain a substrate with amino groups modified on the surface, wherein the substrate is glass.

[0031] Furthermore, the preparation method of compound 3 comprises the following steps:

[0032] Compound 1 and POCl3 are used as raw materials, dissolved in a seventh solvent, and subjected to a formylation reaction at room temperature to obtain compound 2; the synthetic reaction formula is shown below:

[0033] .

[0034] Compound 2 and N-bromosuccinimide are used as raw materials, dissolved in an eighth solvent, and subjected to a substitution reaction at room temperature to obtain compound 3; the synthetic reaction formula is shown below:

[0035] .

[0036] Furthermore, the molar ratio of compound 1 and POCl3 is 1:2.8~3.0, and before the formylation reaction, it is stirred at -1℃~1℃ for 1h, and the formylation reaction time is 8h~12h; the molar ratio of compound 2 and N-bromosuccinimide is 1:1~1.1, and the substitution reaction time is 2h~4h.

[0037] Furthermore, the preparation method of compound b comprises the following steps:

[0038] Compound a and isopropyl pinacol borate are used as raw materials, and a borylation reaction is carried out at room temperature in the presence of an n-butyl lithium catalyst and a ninth solvent to obtain compound b. The molar ratio of compound a to isopropyl pinacol borate is 1:2 to 2.1, and the borylation reaction time is 10 to 14 hours. The synthetic reaction formula is shown below:

[0039] .

[0040] The third object of the present invention is to provide the use of the above-mentioned dicyanoethylene fluorescent material in the preparation and detection of biogenic amine products.

[0041] The beneficial effects of the present invention are as follows:

[0042] The dicyanoethylene-based fluorescent material provided by the present invention is constructed by constructing a dicyanoethylene active group on the mother ring of a dithienylamine derivative with fluorescent properties. When the fluorescent material comes into contact with a biogenic amine, due to the nucleophilic properties of the biogenic amine, a nucleophilic substitution reaction can occur with the dicyanoethylene group of the probe molecule to generate an imine chemical structure. Moreover, since the electron-withdrawing ability of the dicyanoethylene is stronger than that of the imine, the intramolecular charge transfer effect of the fluorescent material is drastically reduced, resulting in a blue shift in the absorption and luminescence properties of the molecules within the fluorescent material, emitting strong fluorescence and a significant color change. The concentration of the biogenic amine can also be accurately fed back through the change in the fluorescence signal, so that the glass-based ratio fluorescent material solves the technical problem of the inconvenience of using the existing biogenic amine detection method.

[0043] The fluorescent probe provided by the present invention, when R is hydrogen, the fluorescent material formed can accurately identify and detect biogenic amines in solution, has high sensitivity and selectivity, and can effectively reduce interference from other substances even in solution systems with complex components such as biological samples and food extracts. The concentration of biogenic amines is accurately fed back through changes in the fluorescence signal, providing reliable quantitative analysis data for scenarios such as scientific research, clinical testing or quality control, and helping to conduct in-depth research on the behavior and effects of biogenic amines in solution environments. The structurally modified probe is loaded on a substrate with amino groups on the surface to form a fluorescent material, which can accurately identify and detect gaseous biogenic amines. Compared with solution probes, its physicochemical properties are more stable, and it can resist external environmental interference such as humidity and slight vibration, making it suitable for gaseous biogenic amine detection in complex environments. At the same time, this probe is reusable, reducing the cost of single use, and is easy to carry and operate on-site, such as rapid detection in food markets and industrial sites, expanding the application scenarios, and is particularly suitable for fields such as rapid screening of food safety and environmental monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a synthetic route for the fluorescent probe provided in Example 2 of the present invention loaded on glass with amino groups on its surface.

[0045] Figure 2 This is a fluorescence performance diagram of the fluorescent material EBTN1 in Example 1 of the present invention detecting n-octylamine. Figure 2 Figure (a) shows the absorption change of EBTN1 caused by the addition of n-octylamine, and Figure (b) shows the continuous change of fluorescence of EBTN1 solution with the continuous addition of n-octylamine.

[0046] Figure 3 This is a test chart of the selectivity and anti-interference performance of the fluorescent material EBTN1 for n-octylamine detection in Example 1 of the present invention. Figure 3 Figure (a) is the selectivity test diagram, and Figure (b) is the anti-interference test diagram.

[0047] Figure 4 This is the reaction mechanism for detecting the fluorescent material EBTN1 in Example 1 of the present invention. Figure 4 (a) shows the reversible reaction of EBTN1 and primary amine, and (b) shows the HOMO-LUMO distribution and energy level diagram of EBTN1 and the recognition product EBTN-imine.

[0048] Figure 5 This is a graph showing the detection performance of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention for biogenic amines. Figure 5 Figure (a) shows ordinary glass, (b) shows the absorption and emission spectra of 9-glass; (c) shows the absorption and emission spectra of the probe-loaded glass slide, i.e., EBTN1D-glass; (d) shows the absorption and emission spectra of EBTN1D-glass after reaction with biogenic amines.

[0049] Figure 6 This is the cyclic stability of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention in detecting biogenic amines. DETAILED DESCRIPTION

[0050] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention is further described below with reference to specific examples, but the examples are not intended to limit the present invention. The following experimental and detection methods are conventional methods unless otherwise specified; the reagents and raw materials are commercially available unless otherwise specified.

[0051] The present invention is described in detail below through specific examples. The examples are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0052] A dicyanoethylene-based fluorescent material, wherein the fluorescent material is a fluorescent probe having a chemical structure as shown in Formula I:

[0053] .

[0054] Wherein, R is hydrogen or , is the connection site;

[0055] When R is When the fluorescent probe is loaded on a substrate having amino groups on the surface.

[0056] The dicyanoethylene-based fluorescent material provided by the present invention is constructed by constructing a dicyanoethylene active group on the mother ring of a dithienylamine derivative with fluorescent properties. When the fluorescent material comes into contact with a biogenic amine, due to the nucleophilic properties of the biogenic amine, a nucleophilic substitution reaction can occur with the dicyanoethylene group of the probe molecule to generate an imine chemical structure. Moreover, since the electron-withdrawing ability of the dicyanoethylene is stronger than that of the imine, the intramolecular charge transfer effect of the fluorescent material is drastically reduced, resulting in a blue shift in the absorption and luminescence properties of the molecules within the fluorescent material, emitting strong fluorescence and a significant color change. The concentration of the biogenic amine can also be accurately fed back through the change in the fluorescence signal, so that the glass-based ratio fluorescent material solves the technical problem of the inconvenience of using the existing biogenic amine detection method.

[0057] 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, has high sensitivity and selectivity, and can effectively reduce interference from other substances even in solution systems with complex components, such as biological samples and food extracts. The concentration of biogenic amines is accurately fed back through changes in the fluorescence signal, providing reliable quantitative analysis data for scenarios such as scientific research, clinical testing, or quality control, and helping to conduct in-depth research on the behavior and effects of biogenic amines in solution environments. The structurally modified probe is loaded on a substrate with amino groups on the surface to form a fluorescent material that can accurately identify and detect gaseous biogenic amines. Compared with solution probes, its physicochemical properties are more stable, and it can resist external environmental interference such as humidity and slight vibration. It is suitable for gaseous biogenic amine detection in complex environments. At the same time, this probe is reusable, reducing the cost of single use, and is easy to carry and operate on-site, such as rapid detection in food markets and industrial sites, expanding the application scenarios, and is particularly suitable for rapid screening of food safety, environmental monitoring and other fields.

[0058] The following is further described through specific examples.

[0059] Example 1

[0060] This embodiment provides a fluorescent material, and the specific preparation method is as follows:

[0061] 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. The mixture is cooled to 0°C in an ice bath, and then 500 μL (5.10 mmol) of POCl3 is added dropwise to the mixture. The mixture is stirred at 0°C for 1 h, and finally reacted at room temperature for 10 h.

[0062] After completion of the reaction, the reaction was quenched with 5 mL of 1 M sodium hydroxide to obtain a mixed solution, which was then washed sequentially with 100 mL of water and 100 mL of brine. The organic phase was then separated and dried over anhydrous magnesium sulfate. The desiccant was filtered out and purified 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 shown below:

[0063] .

[0064] 1H 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 [M+H] of NO2S2 + The calculated value is 314.0309 and the found value is 314.0296.

[0065] Step 2: 170 mg (0.54 mmol) of compound 2 was dissolved in 10 mL of tetrahydrofuran, and then 103 mg (0.58 mmol) of N-bromosuccinimide was added to form a mixture. The mixture was stirred at room temperature for 3 h to react, and a reaction liquid was formed after the reaction was completed.

[0066] 50 mL of dichloromethane and 50 mL of water were added to the reaction solution in sequence, and the aqueous phase was separated. The aqueous phase was further extracted three times with 50 mL of dichloromethane. The three extracts were combined, and then anhydrous magnesium sulfate was added as a desiccant to remove residual moisture. The desiccant was filtered out, and finally evaporated under reduced pressure to obtain 200 mg of compound 3 with a yield of 94%. The synthetic reaction formula is shown below:

[0067] .

[0068] 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 [M+H] of BrNO2S2 + The calculated value is 391.9415 and the found value is 391.9409.

[0069] Step 3, 1.00 g, 2.13 mmol, of compound a was dissolved in 10 mL of anhydrous tetrahydrofuran solution. Under an argon atmosphere, a 2.5 M hexane solution containing 2.3 mmol of n-butyllithium n-BuLi was added to the above solution at -78 ° C. After stirring for 1 h, 0.80 g, 4.26 mmol of isopropyl 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 to obtain a reaction solution.

[0070] The reaction mixture was extracted with 15 mL of ethyl acetate three times. The organic phases from the three extractions were combined, and residual moisture was removed by adding anhydrous magnesium sulfate as a desiccant. After filtering out the desiccant, the mixture was evaporated under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography using dichloromethane as the eluent to obtain 690 mg of compound b with a yield of 63%. The synthetic reaction formula is shown below:

[0071]

[0072] 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 = 7.4Hz, 6H). 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] in BO4 + The calculated value is 516.3285 and the found value is 582.3272.

[0073] Step 4, to 50 mL of tetrahydrofuran solution containing 900 mg of compound 3 with a molar weight of 2.29 mmol and 1.42 g of compound b with a molar weight of 2.75 mmol, 132 mg of transition metal catalyst Pd(PPh3)4 with a molar weight of 0.12 mmol and 15 mL of 1 M NaCO3 solution were added, the mixture was stirred at 100°C under argon atmosphere and refluxed for 6 h to obtain a reaction solution.

[0074] The reaction solution was cooled to room temperature and diluted with 20 mL of dichloromethane. The undissolved catalyst was then removed by filtration through diatomaceous earth. The organic phase was then extracted by washing three times with 150 mL of water. The three extracted organic phases were combined, and residual moisture was removed by adding anhydrous magnesium sulfate as a desiccant. After filtering out the desiccant, the organic solvent was evaporated under reduced pressure to obtain a crude product. The crude product was purified by silica column chromatography using a mixture of petroleum ether and ethyl acetate in a volume ratio of 10:1 as the eluent to obtain 960 mg of compound 4 with a yield of 60%. The synthetic reaction formula is shown below:

[0075] .

[0076] 1 H 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). 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 N2O4S2 + The calculated value is 701.2502 and the found value is 701.2497.

[0077] In step 5, 100 mg (0.14 mmol) of compound 4 and 17 mg (0.28 mmol) of malononitrile were dissolved in 5 mL of N,N-dimethylformamide and stirred at 100°C for 30 min to obtain a mixture. The mixture was evaporated under reduced pressure and then purified by silica column chromatography using a 3:1 volume ratio of dichloromethane and petroleum ether as the eluent to obtain 100 mg of a fluorescent material, designated EBTN1, with a yield of 93%. The synthetic reaction formula is shown below:

[0078] .

[0079] 1 H NMR (400 MHz, CDCl3, ppm) δ 7.67 (s, 1H), 7.62 (s, 1231H), 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). 13C NMR (101MHz, 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 [M+H] of N4O3S2 + The calculated value is 748.2542 and the found value is 748.2524.

[0080] Example 2

[0081] This embodiment provides a fluorescent material, and the specific preparation method is as follows:

[0082] Step 1: 0.50 g (1.75 mmol) of compound 1 was dissolved in 20 mL of anhydrous dichloromethane solution, and then 280 μL (3.60 mmol) of anhydrous N,N-dimethylformamide was added to form a mixture. The mixture was cooled to 0°C in an ice bath, and then 500 μL (5.10 mmol) of POCl3 was added dropwise to the mixture. The mixture was stirred at 0°C for 1 h and then allowed to stand overnight at room temperature.

[0083] After completion of the reaction, the reaction was quenched with 5 mL of 1 M sodium hydroxide to obtain a mixed solution, which was then washed sequentially with 100 mL of water and 100 mL of brine. The organic phase was then separated and dried over anhydrous magnesium sulfate. The desiccant was filtered out and purified 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 shown below:

[0084] .

[0085] 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). 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 [M+H] of NO2S2 + The calculated value is 314.0309 and the found value is 314.0296.

[0086] Step 2: 170 mg (0.54 mmol) of compound 2 was dissolved in 10 mL of tetrahydrofuran, and then 103 mg (0.58 mmol) of N-bromosuccinimide was added to form a mixture. The mixture was stirred at room temperature for 3 h to react, and a reaction liquid was formed after the reaction was completed.

[0087] 50 mL of dichloromethane and 50 mL of water were added to the reaction solution in sequence, and the aqueous phase was separated. The aqueous phase was further extracted three times with 50 mL of dichloromethane. The three extracts were combined, and then anhydrous magnesium sulfate was added as a desiccant to remove residual moisture. The desiccant was filtered out, and finally evaporated under reduced pressure to obtain 200 mg of compound 3 with a yield of 94%. The synthetic reaction formula is shown below:

[0088] .

[0089] 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 [M+H] of BrNO2S2 + The calculated value is 391.9415 and the found value is 391.9409.

[0090] Step 3, 1.00 g, 2.13 mmol, of compound a was dissolved in 10 mL of anhydrous tetrahydrofuran solution. Under an argon atmosphere, a 2.5 M hexane solution containing 2.3 mmol of n-butyllithium n-BuLi was added to the above solution at -78 ° C. After stirring for 1 h, 0.80 g, 4.26 mmol of isopropyl 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 to obtain a reaction solution.

[0091] The reaction solution was extracted three times with 15 mL of ethyl acetate, and the organic phases from the three extractions were combined. Anhydrous magnesium sulfate was added as a desiccant to remove residual moisture. After filtering out the desiccant, the mixture was evaporated under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography using dichloromethane as the eluent to obtain 690 mg of compound b with a yield of 63%. The synthetic reaction formula is shown below:

[0092] .

[0093] 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 = 7.4Hz, 6H). 13 C 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] in BO4 + The calculated value is 516.3285 and the found value is 582.3272.

[0094] Step 4: Under an argon atmosphere, 10.2 mL of a 1M BBr3 solution in dichloromethane (molar weight: 10.2 mmol) was added dropwise to a 0°C solution of 1.0 g of compound 3 (molar weight: 2.55 mmol) in 200 mL of anhydrous dichloromethane. The mixture was stirred at room temperature for 6 h at 100°C, and then 10 mL of water was added to quench the reaction to form a mixed solution.

[0095] The mixed solution was filtered to obtain a solid and a filtrate. The separated solid was washed with 250 mL of 1M 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 a desiccant (magnesium sulfate) was added to remove residual moisture. After filtering out the desiccant, the organic solvent was evaporated under reduced pressure to obtain an oily crude product. The crude product was purified by silica column chromatography using a mixture of dichloromethane and ethyl acetate in a volume ratio of 10:1 as the eluent to obtain 895 mg of compound 5 with a yield of 93%. The synthetic reaction formula is shown below:

[0096] .

[0097] 1 H 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 C 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: C 15 [M+H] of H9BrNO2S2 + The calculated value is 377.9258 and the found value is 377.9252.

[0098] Step 5: To a solution containing 960 mg (2.55 mmol) of compound 5 and 1.1 g (7.65 mmol) of KCO in 250 mL of N,N-dimethylformamide was added dropwise 0.60 g (3.06 mmol) of ethyl 4-bromobutyrate to form a mixture. The mixture was stirred at 60°C for 8 h to obtain a reaction solution.

[0099] The reaction solution was evaporated under reduced pressure to remove most of the N,N-dimethylformamide, forming a concentrate. 50 mL of ethyl acetate was added to the concentrate to redissolve it, and then 150 mL of water was added for washing. The aqueous phase and filtrate were separated. The aqueous phase was then extracted twice with 150 mL of ethyl acetate, respectively. The two extracts were combined to obtain an organic phase. The organic phase and filtrate were mixed and washed with 100 mL of water to separate the organic phase. Anhydrous magnesium sulfate was added as a desiccant to the organic phase to remove residual moisture. The desiccant was then filtered to remove the desiccant. Finally, the crude product was evaporated under reduced pressure to obtain a crude product. The crude product was purified by chromatography on a silica gel column with dichloromethane as the eluent to obtain 1.20 g of compound 6 with a yield of 96%. The synthetic reaction formula is shown below:

[0100] .

[0101] 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 H 19 [M+H] of BrNO4S2 + The calculated value is 491.9933 and the found value is 491.9935.

[0102] Step 6. Under an argon atmosphere, to a 2 mL tetrahydrofuran solution containing 38 mg (molar weight 0.07 mmol) of compound b and 30 mg (molar weight 0.06 mmol) of compound 6, was added 0.2 mL of a 1 M K2CO3 solution containing 35 mg (molar weight 0.03 mmol) of catalyst Pd(PPh3)4. The mixture was stirred and refluxed at 100°C for 8 h, and then the mixture was cooled to room temperature to obtain a reaction solution.

[0103] 20 mL of dichloromethane was added to the reaction solution for dilution. The undissolved catalyst was removed by filtration through diatomaceous earth to obtain a filtrate. The filtrate was washed with 150 mL of water and the organic phase was separated. Anhydrous magnesium sulfate was added to the organic phase to remove residual moisture. After filtering out the desiccant, the organic phase was evaporated under reduced pressure to obtain a crude product. The crude product was purified by silica column chromatography using a 1:1 volume ratio of dichloromethane to petroleum ether as the eluent to obtain 45 mg of compound 7 with a yield of 76%. The synthetic reaction formula is shown below:

[0104] .

[0105] 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). 13C 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 N2O6S2 + The calculated value is 800.2948 and the found value is 800.2942.

[0106] In step 7, 3 mL of 12 M hydrochloric acid was added to a 12 mL tetrahydrofuran solution containing 80 mg (1.00 mmol) of compound 7, and the mixture was stirred at room temperature overnight to obtain a reaction solution.

[0107] The reaction solution was extracted three times with 50 mL of dichloromethane, the extracts from the three extractions were mixed, 100 mL of water was added to the resulting organic phase for washing, and the organic phase was separated. Anhydrous magnesium sulfate was added to the organic phase to remove residual moisture, the desiccant was filtered out, and finally evaporated under reduced pressure to obtain a crude product. The crude product was purified by chromatography on a silica column using a 2:3 volume ratio of dichloromethane and ethyl acetate as the eluent to obtain 76 mg of compound 8 with a yield of 97%. The synthetic reaction formula is shown below:

[0108] .

[0109] 1H 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 C NMR (101 MHz, CDCl3, ppm) δ182.8, 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 N2O6S2 + The calculated value is 773.2714 and the found value is 772.2683.

[0110] Step 8. Under an argon atmosphere, 23 mg (0.20 mmol) of N-hydroxysuccinimide and 38 mg (0.20 mmol) of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to a 5 mL anhydrous N,N-dimethylformamide solution containing 77 mg (0.10 mmol) of compound 8. The mixture was stirred at room temperature for 8 h to obtain a reaction solution.

[0111] 50 mL of dichloromethane was added to the reaction solution, followed by washing with 50 mL of saturated NaHCO₃ solution and 100 mL of water. The organic phase was separated and anhydrous magnesium sulfate was added to remove residual moisture. After filtering out the desiccant, the organic phase was evaporated under reduced pressure to obtain a crude product. The crude product was purified by silica column chromatography using a 1:1 volume ratio mixture of dichloromethane and petroleum ether as the eluent, yielding 71 mg of compound 9 with a yield of 82%. The synthetic reaction formula is shown below:

[0112] .

[0113] 1 H 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 C NMR (101MHz, 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 [M+H] of N2O4S2 + The calculated value is 870.2877 and the found value is 870.2892.

[0114] Step 10, such as Figure 1As shown, using glass as a substrate, the surface was cleaned using detergent, water, acetone, and methanol in sequence, with each cleaning step requiring ultrasonic treatment for 15 minutes to obtain a clean glass surface. The glass was then immersed in a methanol solution containing 5% APTES by mass and allowed to stand at room temperature for 50 minutes. The glass was then washed with methanol and dried at 120°C for 30 minutes to obtain silanized glass.

[0115] Step 11, at room temperature, soak the glass obtained in step 10 in a methanol solution containing 100 μM compound 9 for 12 hours, then rinse with methanol and dry naturally to obtain a glass loaded with compound 9, named 9-glass; then soak the 9-glass in a 10 mM malononitrile solution at room temperature for 2 hours, and finally rinse the glass with methanol to obtain a solid substrate loaded with a fluorescent probe, that is, a fluorescent material, named EBTN1D-glass.

[0116] The fluorescent material EBTN1 prepared in Example 1 is used to detect biogenic amines, comprising the following steps:

[0117] 1.87 mg of EBTN1 was dissolved in dimethyl sulfoxide and the volume was fixed in a 5 mL volumetric flask to obtain an EBTN1 stock solution. The concentration of the EBTN1 stock solution was 2.5 μM.

[0118] Dissolve 8.2 μL of n-octylamine in dimethyl sulfoxide and dilute to volume in a 50 mL volumetric flask to form an n-octylamine stock solution. The concentration of the n-octylamine stock solution is 1.0 mM.

[0119] Add 20 μL of the EBTN1 stock solution to each of 11 5 mL volumetric flasks. Then, add a different 50 μL volume of n-octylamine solution to each flask. Dilute to the flask mark with dimethyl sulfoxide and store in the dark for 14 hours. Finally, measure UV / Vis and fluorescence spectra.

[0120] Figure 2 This is a fluorescence performance diagram of the fluorescent material EBTN1 in Example 1 of the present invention detecting n-octylamine. Figure 2 Figure (a) shows the change in the absorption of EBTN1 caused by the addition of n-octylamine, and Figure (b) shows the change in the fluorescence of EBTN1 solution with the continuous addition of n-octylamine. Figure 2As shown in Figure (a), with the increase of n-octylamine concentration, the characteristic intramolecular charge transfer absorption band at 530nm continues to weaken, accompanied by the fading of the purple color of the dye solution. At the same time, a new peak appears at 410nm. The presence of an isosbestic point at 460nm 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 556nm and steadily enhances. At a high concentration of 10μM, the probe reacts rapidly with amines, and changes 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 shown in Figure 5 Figure 2 As shown in (b), the theoretical detection limit of n-octylamine is as low as 160 nM at a dye concentration of 5 μM. Furthermore, the transition from the dicyanovinyl group to the imide form is accompanied by a distinct color change, which can be attributed to the reduction of the intramolecular charge transfer properties.

[0121] The selectivity of EBTN1 towards primary amines was evaluated by monitoring the fluorescence change at 556 nm after the addition of different nucleophiles, including primary amines such as putrescine, tyramine, cadaverine, octylamine, propylamine, histamine, tryptamine, spermidine, and 1,3-propylenediamine; secondary amines such as diethylamine and diisopropylamine; tertiary amines such as triethylamine; aromatic amines such as pyridine and aniline; and thiols such as ethanethiol.

[0122] Figure 3 This is a test chart of the selectivity and anti-interference performance of the fluorescent material EBTN1 for n-octylamine detection in Example 1 of the present invention. Figure 3 (a) is the selectivity test chart, and (b) is the anti-interference test chart. Figure 3 As shown, all primary amines resulted in enhanced EBTN1 fluorescence. In contrast, none of the secondary amines, such as diethylamine and diisopropylamine, nor any of the tertiary amines, such as triethylamine, nor any of the aromatic amines, such as pyridine and aniline, nor any of the thiols, such as ethanethiol, exhibited such fluorescence enhancement under the given conditions. Subsequently, when n-octylamine was added to these unreactive mixtures, intense fluorescence and a significant color change were immediately observed. This result emphasizes the selectivity of EBTN1 for primary amines and indicates the absence of interference from other analytes.

[0123] Figure 4 This is the reaction mechanism for detecting the fluorescent material EBTN1 in Example 1 of the present invention. Figure 4 Figure (a) shows the reversible reaction between EBTN1 and primary amine, and Figure (b) shows 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. Figure 4As shown in (a), the significant color change observed when switching from dicyanovinyl to imine can be clearly explained by the reduction of intramolecular charge transfer. Figure 4 This is confirmed by DFT calculations of EBTN1 and EBTN-imine, shown in Figure (b). The highest occupied molecular orbitals (HOMOs) of both molecules are distributed throughout the conjugated backbone, while the lowest unoccupied molecular orbitals (LUMOs) are primarily located on the acceptor, indicating the presence of molecular charge transfer. Clearly, the electron-withdrawing ability of the imine group is weaker, resulting in elevated LUMO and HOMO energy levels. Consequently, the energy level difference (ΔE) of EBTN-imine increases compared to EBTN1, from 2.24 eV to 3.04 eV, resulting in a blue shift in the spectrum.

[0124] The fluorescent material EBTN1D-glass prepared in Example 2 is used to detect biogenic amines, comprising the following steps:

[0125] Figure 5 This is a graph showing the detection performance of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention for biogenic amines. Figure 5 (a) is ordinary glass, (b) is the absorption and emission spectra of 9-glass; (c) is the absorption and emission spectra of EBTN1D-glass; (d) is the absorption and emission spectra of EBTN1D-glass after reaction with biogenic amine. Figure 5 As shown in Figures (a) to (b), in order to realize the cyclic detection of biogenic amine gas by the probe, compound 9 was covalently grafted onto the glass surface. The absorption peak and emission peak of 9-glass at 430nm and 555nm indicate that 9 was successfully modified on the glass surface. Figure 5 As shown in Figure (c), after 9-glass is immersed in a malononitrile solution, the slide turns red, and the absorption peak and emission peak of the glass material are detected to be red-shifted to 542nm and 660nm, respectively, indicating that 9-glass is converted into the fluorescent material EBTN1D-glass. When the fluorescent material EBTN1D-glass is placed in saturated n-propylamine vapor for 5 minutes, its absorption band at 542nm blue-shifts to 420nm, and a corresponding new fluorescence peak appears at 523nm, proving that the fluorescent material EBTN1D-glass can perform a ratiometric fluorescence response to primary amine gas. This is due to the strong emission characteristics of the imine structure. In the n-propylamine atmosphere, the fluorescent material EBTN1D-glass shows bright blue fluorescence. Figure 5 In Figures (d) to (c), after reacting EBTN1D-glass with biogenic amines and then immersing it in a malononitrile solution, the fluorescent material EBTN1D-glass recovered its initial absorption and fluorescence emission spectra, demonstrating its regenerative nature and the recyclability of EBTN1D-glass for primary amine gas detection.

[0126] Figure 6The cyclic stability of the fluorescent material EBTN1D-glass prepared in Example 2 of the present invention for the detection of biogenic amines. Figure 6 As shown in Figure 3, after 6 cycles, the emission fluorescence of EBTN1D-glass decays by less than 90%, indicating that the device has good sensing stability.

[0127] The above description is merely a preferred embodiment of the present invention, and the above specific embodiment is not intended to limit the present invention. Various variations and modifications are possible within the technical scope of the present invention. Any modifications, alterations, or equivalent substitutions made by a person skilled in the art based on the above description are within the scope of protection of the present invention.

Claims

1. A fluorescent material based on dicyanoethylene, characterized in that The fluorescent material is a fluorescent probe, and the fluorescent probe has a chemical structure as shown in Formula I: ； Wherein, R is methyl or , is the connection site; When R is When the fluorescent probe is loaded on a substrate having amino groups on the surface.

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

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

5. The method for preparing a dicyanoethylene-based fluorescent material according to claim 4, wherein: The molar ratio of compound 3 to BBr3 is 1:3-5, and the demethylation reaction time is 4h-6h; 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 6h-8h; The molar ratio of compound 6 to compound b is 1:1.1-1.2, and the coupling reaction time is 8h-12h; The acid used for hydrolysis is hydrochloric acid, and the concentration of hydrochloric acid is 11M to 13M; The molar ratio of compound 8, 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 8h-12h; The concentration of the compound 9 solution is 95 μM to 105 μM, and the second condensation reaction time 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 method for preparing a dicyanoethylene-based fluorescent material according to claim 4, wherein: The substrate is subjected to silanization treatment, comprising the following steps: The substrate is cleaned, and then immersed in a γ-aminopropyltriethoxysilane solution with a mass concentration of 4% to 6% for 45 minutes to 60 minutes at room temperature to obtain a substrate with amino groups modified on the surface, wherein the substrate is glass.

7. The method for preparing a dicyanoethylene-based fluorescent material according to claim 2 or claim 4, wherein: The preparation method of compound 3 comprises the following steps: Compound 1 and POCl3 are used as raw materials, dissolved in a seventh solvent, and subjected to a formylation reaction at room temperature to obtain compound 2; the synthetic reaction formula is shown below: ； Compound 2 and N-bromosuccinimide are used as raw materials, dissolved in an eighth solvent, and subjected to a substitution reaction at room temperature to obtain compound 3; the synthetic reaction formula is shown below: 。 8. The method for preparing a dicyanoethylene-based fluorescent material according to claim 7, wherein: The molar ratio of compound 1 and POCl3 is 1:2.8~3.

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

9. The method for preparing a dicyanoethylene-based fluorescent material according to claim 2 or claim 4, wherein: The preparation method of compound b comprises the following steps: Compound a and isopropyl pinacol borate are used as raw materials, and a borylation reaction is carried out at room temperature in the presence of an n-butyl lithium catalyst and a ninth solvent to obtain compound b. The molar ratio of compound a to isopropyl pinacol borate is 1:2 to 2.1, and the borylation reaction time is 10 to 14 hours. The synthetic reaction formula is shown below: 。 10. Use of the dicyanoethylene-based fluorescent material according to claim 1 in the preparation and detection of biogenic amine products, characterized in that: The biogenic amine is a primary amine, and the primary amine is putrescine, tyramine, cadaverine, octylamine, propylamine, histamine, tryptamine, spermidine or 1,3-propylenediamine.

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