Fluorescent probe molecule for detecting perfluorooctanoic acid as well as preparation method and application of fluorescent probe molecule

Abstract

The invention relates to the technical field of pollutant detection, and discloses a fluorescent probe molecule for detecting perfluorooctanoic acid as well as a preparation method and application thereof. The fluorescent probe molecule comprises a benzyl biphenyl group connected with a tetraphenyl ethylene group; the fluorescent probe molecule is of a hexagonal annular structure, tetraphenylethylene groups distributed on the annular structure of the fluorescent probe molecule can be combined with perfluorooctanoic acid and generate fluorescence, and the tetraphenylethylene groups are luminous chromophores; the molecular general formula of the fluorescent probe molecule is C100H76F24N4P4. The molecular formula of the fluorescent probe molecule is shown in the description. The cyclic structure provides a space for the combination of a tetraphenyl ethylene group and a perfluorooctanoic acid molecule, so that the combined tetraphenyl ethylene group becomes a luminescent chromophore, and has obvious fluorescence response. According to the invention, tetraphenyl ethylene monopyridine is obtained through a coupling reaction, and fluorescent probe molecules are prepared through a dehalogenation reaction and anion replacement, so that a new synthesis path is provided. The probe is used for detecting perfluorooctanoic acid and has good detection sensitivity.

Description

Technical Field

[0001] The present invention relates to the technical field of pollutant detection, and in particular to a fluorescent probe molecule for detecting perfluorooctanoic acid, and a preparation method and application thereof. Background Art

[0002] Perfluorooctanoic acid (PFOA) is widely used in textiles, semiconductors, nano-coatings, firefighting foams, medical devices, etc. due to its high physical and chemical stability, strong hydrophobicity and oleophobicity, and high surface activity. However, PFOA has environmental persistence, bioaccumulation, and long-range migration. It can enter the human body through food, air, or water, accumulate in the organs, immune, endocrine, and reproductive development systems of animals, and produce toxicity, seriously threatening the ecological environment and human health. It has been listed in the list of persistent polluting organic substances (POPs).

[0003] Currently, the main methods for detecting PFOA are high performance liquid chromatography and gas chromatography-mass spectrometry, both of which have the defects of complex operation, high instrument cost and long detection cycle, which limits the detection of PFOA.

[0004] The fluorescence analysis method in the prior art has the advantages of high sensitivity, fast detection rate and simple operation, and has become one of the most promising detection methods.

[0005] Therefore, it is of great significance to design and synthesize new fluorescent probes to achieve highly sensitive and rapid detection of target compounds, especially PFOA. Summary of the invention

[0006] In view of the above problems, the first purpose of the present invention is to propose a fluorescent probe molecule for detecting perfluorooctanoic acid to solve the problem of perfluorooctanoic acid detection.

[0007] Furthermore, the second purpose of the present invention is to provide a method for preparing a fluorescent probe molecule to achieve the synthesis of a fluorescent probe molecule for detecting perfluorooctanoic acid.

[0008] Furthermore, the third object of the present invention is to propose a method for using the fluorescent probe molecule perfluorooctanoic acid in acetonitrile aqueous solution to detect perfluorooctanoic acid in pollutants.

[0009] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0010] A fluorescent probe molecule for detecting perfluorooctanoic acid, the fluorescent probe molecule comprising a benzyl biphenyl group connected to a tetraphenylethylene group;

[0011] The fluorescent probe molecule is in a hexagonal ring structure, and the tetraphenylethylene groups distributed in the ring structure of the fluorescent probe molecule can combine with perfluorooctanoic acid and generate fluorescence, and the tetraphenylethylene groups are luminescent chromophores;

[0012] The molecular formula of the fluorescent probe molecule is C 100 H 76 F 24 N4P4;

[0013] Preferably, a plurality of luminescent chromophores are centrally symmetrically distributed in the ring structure.

[0014] Furthermore, the present invention proposes a method for preparing a fluorescent probe molecule for preparing the above-mentioned fluorescent probe molecule for detecting perfluorooctanoic acid, comprising the following steps:

[0015] S1) adding 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) and 4-pyridineboric acid to a stirred reaction vessel, respectively, and then adding N,N-dimethylformamide solution, and dissolving N,N-dimethylformamide uniformly to prepare a mixed solution;

[0016] S2) adding an alkaline agent to the mixed solution, placing a magnetic bar, adding a catalyst, and repeatedly evacuating and filling with nitrogen three times to obtain a reaction solution;

[0017] S3) Under nitrogen protection, the reaction temperature of the reaction solution is controlled, and the reaction solution is stirred until the coupling reaction stops, and then cooled to room temperature, the reaction solution is filtered, and the filtrate is taken and the remaining N,N-dimethylformamide is removed by rotary evaporation to obtain a crude product;

[0018] S4) using neutral Al2O3 as the stationary phase and a mixture of dichloromethane and petroleum ether as the eluent, purifying the crude product by column chromatography, then removing the organic solvent by rotary evaporation, and then vacuum drying the obtained solid to remove the residual organic solvent, thereby obtaining an organic ligand of tetraphenylethylene monopyridine;

[0019] S5) dissolving the organic ligand in acetonitrile to obtain an organic ligand solution;

[0020] S6) dissolving 4,4-dibromomethylbiphenyl in acetonitrile, and then slowly dropping it into the organic ligand solution, controlling the reaction temperature, stirring until the dehalogenation reaction stops, cooling to room temperature, filtering with suction, adding an excess of a first anion displacer to the obtained filtrate, so that the solution completely precipitates a first precipitate, filtering with suction to obtain a filter cake, dissolving the filter cake in deionized water, filtering with suction to obtain a filtrate, and then adding an excess of a second anion displacer to the filtrate, so that the filtrate completely precipitates a second precipitate, purifying the second precipitate, and obtaining the fluorescent probe molecule.

[0021] Preferably, in step S2), the catalyst is tetrakistriphenylphosphine palladium.

[0022] Preferably, in step S2), the alkaline agent is potassium carbonate dissolved in deionized water, and the molar ratio of the alkaline agent to 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) is (4-8):1.

[0023] Preferably, in steps S1) to S2), the molar ratio of 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) to 4-pyridineboronic acid is 1:(2-3).

[0024] Preferably, the reaction temperature of step S3) is 90-110°C, and the reaction temperature of step S6) is 70-90°C;

[0025] In step S4), the volume ratio of dichloromethane and petroleum ether contained in the eluent is 3:1.

[0026] Preferably, in step S6), the first anion displacer is tetrabutylammonium chloride or tetrabutylammonium iodide, and the second anion displacer is ammonium hexafluorophosphate.

[0027] Furthermore, the present invention also proposes a method for detecting perfluorooctanoic acid using a fluorescent probe molecule, wherein the fluorescent probe molecule prepared by the above method for preparing the fluorescent probe molecule comprises the following steps:

[0028] T1) adding acetonitrile and deionized water in a container in a volume ratio of 1:9 to prepare a detection solvent;

[0029] T2) Add 5 mL of detection solvent to a cuvette, and then add 10 -4 mol / L perfluorooctanoic acid to prepare a first control sample;

[0030] T3) Add 5 mL of the detection solvent to the second cuvette, and then add a 10 -5 mol / L of fluorescent molecular probe to prepare a second control sample;

[0031] T3) Take five other cuvettes, add 5 mL of detection solvent to each, and then add 10 -5 mol / L of fluorescent molecular probe, and then adding corresponding molar concentrations of perfluorooctanoic acid into five cuvettes according to the molar concentration ratios of the fluorescent molecular probe to perfluorooctanoic acid of 100:1, 10:1, 1:1, 1:10 and 1:100, respectively, to prepare five test samples;

[0032] T4) Using a fluorescence spectrometer to illuminate the two control samples and each test sample, and obtain corresponding fluorescence spectra.

[0033] The beneficial effect of the technical solution of the present invention is that the fluorescent probe molecule for detecting perfluorooctanoic acid has a ring structure, which can provide space for the tetraphenylethylene group of the luminescent chromophore to combine with the perfluorooctanoic acid molecule to be detected, so that the tetraphenylethylene group after combination becomes a luminescent chromophore and has an obvious fluorescence response within the effective detection concentration range.

[0034] Furthermore, the preparation method of the fluorescent probe molecule proposed in the present invention obtains tetraphenylethylene monopyridine through a coupling reaction, and obtains the fluorescent probe molecule through a dehalogenation reaction and anion replacement, which provides a new process path for synthesizing fluorescent probes for detecting PFOA.

[0035] Furthermore, the method for detecting perfluorooctanoic acid using fluorescent probe molecules proposed in the present invention has a low dosage of fluorescent probe molecules and has obvious fluorescent response phenomenon and good sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The fluorescent probe molecule for detecting perfluorooctanoic acid of the present invention 1 H NMR characterization diagram;

[0037] Figure 2 The organic ligand prepared by the present invention 1 H NMR spectrum;

[0038] Figure 3 The fluorescent molecular probe prepared in the embodiment of the present invention is -5 M, the fluorescence spectra of the test samples of different molar concentrations of perfluorooctanoic acid; 1# is the concentration of 10 -4 The control sample of perfluorooctanoic acid with a concentration of 10 -5 The fluorescence spectrum of the control sample of the fluorescent molecular probe of M#, the fluorescence spectrum of the control sample 1# is the horizontal baseline in the figure;

[0039] Figure 4 The fluorescent molecular probe prepared in the embodiment of the present invention is -5 M, fluorescence photos of the test samples with different molar concentrations of PFOA;

[0040] Figure 5 The ESI-MS spectrum of the fluorescent molecular probe prepared in the embodiment of the present invention;

[0041] Figure 6 The ESI-MS spectrum of the organic ligand prepared in the embodiment of the present invention;

[0042] Among them, C1 is a fluorescent molecular probe; PFOA is perfluorooctanoic acid, 1# is the 1# control sample; 2# is the 2# control sample. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0044] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0045] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0046] A fluorescent probe molecule for detecting perfluorooctanoic acid, the fluorescent probe molecule comprising a tetraphenylethylene group and a connected benzylbiphenyl group;

[0047] The fluorescent probe molecule is in a hexagonal ring structure, and the tetraphenylethylene groups distributed in the ring structure of the fluorescent probe molecule can combine with perfluorooctanoic acid and generate fluorescence, and the tetraphenylethylene groups are luminescent chromophores;

[0048] The molecular formula of the fluorescent probe molecule is C 100 H 76 F 24 N4P4;

[0049] The fluorescent probe molecule for detecting perfluorooctanoic acid of the present invention contains a benzyl biphenyl group connected to a tetraphenylethylene group to form a ring structure, and the ring structure provides a space for the tetraphenylethylene group to combine with the perfluorooctanoic acid molecule to be detected, so that the tetraphenylethylene group can become a luminescent chromophore after combination and have an obvious fluorescence response within the effective detection concentration range. The molecular structure of the fluorescent probe molecule is as follows:

[0050]

[0051] Preferably, a plurality of luminescent chromophores are centrally symmetrically distributed in the ring structure.

[0052] The centrally symmetrical distribution structure of multiple luminescent chromophores makes it easier for the fluorescent probe molecules to aggregate in the acetonitrile aqueous solution containing perfluorooctanoic acid, thereby enhancing the fluorescence effect and improving the detection sensitivity.

[0053] Furthermore, the present invention proposes a method for preparing a fluorescent probe molecule for preparing the above-mentioned fluorescent probe molecule for detecting perfluorooctanoic acid, comprising the following steps:

[0054] S1) adding 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) and 4-pyridineboric acid to a stirred reaction vessel, respectively, and then adding N,N-dimethylformamide solution, and dissolving N,N-dimethylformamide uniformly to prepare a mixed solution;

[0055] S2) adding an alkaline agent to the mixed solution, placing a magnetic bar, adding a catalyst, and repeatedly evacuating and filling with nitrogen three times to obtain a reaction solution;

[0056] S3) Under nitrogen protection, the reaction temperature of the reaction solution is controlled, and the reaction solution is stirred until the coupling reaction stops, and then cooled to room temperature, the reaction solution is filtered, and the filtrate is taken and the remaining N,N-dimethylformamide is removed by rotary evaporation to obtain a crude product;

[0057] S4) using neutral Al2O3 as the stationary phase and a mixture of dichloromethane and petroleum ether as the eluent, purifying the crude product by column chromatography, then removing the organic solvent by rotary evaporation, and then vacuum drying the obtained solid to remove the residual organic solvent, thereby obtaining an organic ligand of tetraphenylethylene monopyridine;

[0058] S5) dissolving the organic ligand in acetonitrile to obtain an organic ligand solution;

[0059] S6) dissolving 4,4-dibromomethylbiphenyl in acetonitrile, and then slowly dropping it into the organic ligand solution, controlling the reaction temperature, stirring until the dehalogenation reaction stops, cooling to room temperature, filtering with suction, adding an excess of a first anion displacer to the obtained filtrate, so that the solution completely precipitates a first precipitate, filtering with suction to obtain a filter cake, dissolving the filter cake in deionized water, filtering with suction to obtain a filtrate, and then adding an excess of a second anion displacer to the filtrate, so that the filtrate completely precipitates a second precipitate, purifying the second precipitate, and obtaining the fluorescent probe molecule.

[0060] The preparation method of the fluorescent probe molecule of the present invention comprises the following steps: preparing tetraphenylethylene monopyridine by a coupling reaction of 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) and 4-pyridine boronic acid, and using tetraphenylethylene monopyridine as an organic ligand to cause a dehalogenation reaction between the organic ligand and 4,4-dibromomethylbiphenyl, followed by anion replacement and purification to obtain the fluorescent probe molecule with a ring structure.

[0061] Preferably, in step S2), the catalyst is tetrakistriphenylphosphine palladium.

[0062] The yield of the organic ligand of tetraphenylethylene monopyridine is improved by the catalytic coupling reaction of tetrakistriphenylphosphine palladium.

[0063] Preferably, in step S2), the alkaline agent is potassium carbonate dissolved in deionized water, and the molar ratio of the alkaline agent to 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) is (4-8):1.

[0064] Potassium carbonate was added to provide an alkaline environment for the reaction solution, and the volume ratio of the N,N-dimethylformamide solution to the deionized water used to dissolve the potassium carbonate was controlled to 7:1, so as to reduce the amount of deionized water used in the reaction solution to avoid affecting the reaction efficiency.

[0065] Preferably, in steps S1) to S2), the molar ratio of 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) to 4-pyridineboronic acid is 1:(2-3).

[0066] Preferably, the reaction temperature of step S3) is 90-110°C, and the reaction temperature of step S6) is 70-90°C;

[0067] In step S4), the volume ratio of dichloromethane and petroleum ether contained in the eluent is 3:1.

[0068] The chemical reaction formula of the tetraphenylethylene monopyridine organic ligand in steps S1) to S4) is as follows:

[0069]

[0070] The chemical reaction formula of steps S5) to S6) is as follows:

[0071]

[0072] Preferably, in step S6), the first anion displacer is tetrabutylammonium chloride or tetrabutylammonium iodide, and the second anion displacer is ammonium hexafluorophosphate.

[0073] The first anion displacer is used to displace the chloride ions introduced during the reaction, and the second anion displacer, ammonium hexafluorophosphate, is used to precipitate the fluorescent molecular probe from the filtrate, thereby improving the purity and yield of the fluorescent molecular probe.

[0074] Furthermore, the present invention also proposes a method for detecting perfluorooctanoic acid using a fluorescent probe molecule, wherein the fluorescent probe molecule prepared by the above method for preparing the fluorescent probe molecule comprises the following steps:

[0075] T1) adding acetonitrile and deionized water in a container in a volume ratio of 1:9 to prepare a detection solvent;

[0076] T2) Add 5 mL of detection solvent to a cuvette, and then add 10 -4mol / L perfluorooctanoic acid to prepare a first control sample;

[0077] T3) Add 5 mL of the detection solvent to the second cuvette, and then add a 10 -5 mol / L of fluorescent molecular probe to prepare a second control sample;

[0078] T3) Take five other cuvettes, add 5 mL of detection solvent to each, and then add 10 -5 mol / L of fluorescent molecular probe, and then adding corresponding molar concentrations of perfluorooctanoic acid into five cuvettes according to the molar concentration ratios of the fluorescent molecular probe to perfluorooctanoic acid of 100:1, 10:1, 1:1, 1:10 and 1:100, respectively, to prepare five test samples;

[0079] T4) Using a fluorescence spectrometer to illuminate the two control samples and each test sample, and obtain corresponding fluorescence spectra.

[0080] The above fluorescence spectra were detected at room temperature. Figure 3 As shown in the figure, C1 in the figure represents the fluorescent probe molecule, PFOA represents perfluorooctanoic acid in the test sample, and the fluorescence intensity of the first control sample (1#) and the second control sample (2#) are close to the baseline. When the molar concentration ratio of the fluorescent molecular probe C1 to perfluorooctanoic acid is 1:1, the fluorescence begins to be significant. As the molar concentration of PFOA increases, the fluorescence emission peak shifts, and the emission peak wavelength shifts from 580nm to 560nm, accompanied by a sharp increase in fluorescence, indicating that the interaction between the increased content of PFOA and the fluorescent molecular probe C1 is continuously enhanced, with an obvious fluorescence response phenomenon; Figure 4 As shown in the figure, when the molar concentration ratio of fluorescent molecular probe C1 to perfluorooctanoic acid is 1:100, the color of the fluorescence emission changes from orange-yellow to yellow-green, indicating that the concentration of 10 -5 mol / L of the fluorescent probe molecule of the present invention can detect the concentration of 10 -5 mol / L or above PFOA concentration, and has good detection sensitivity.

[0081] Example

[0082] 1. Prepare the fluorescent probe molecule of the embodiment according to the following steps:

[0083] S1) 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) (1.020 mmol) and 4-pyridineboric acid (0.326 g, 2.652 mmol) were added to a stirred reaction vessel, and then 42 mL of N,N-dimethylformamide solution was added, and N,N-dimethylformamide was uniformly dissolved to prepare a mixed solution;

[0084] S2) adding an alkaline agent to the mixed solution, placing a magnetic bar, adding a catalyst of tetrakistriphenylphosphine palladium (0.141 g, 0.122 mmol), repeatedly evacuating and filling with nitrogen three times to obtain a reaction solution;

[0085] S3) stirring the reaction solution at 110° C. under nitrogen protection until the reaction stops, then cooling to room temperature, filtering the reaction solution by suction, taking the filtrate and removing N,N-dimethylformamide by rotary evaporation to obtain a crude product;

[0086] S4) using neutral Al2O3 as the stationary phase and a mixture of dichloromethane and petroleum ether in a volume ratio of 3:1 as the eluent, the crude product was purified by column chromatography, and the organic solvent was removed by rotary evaporation. The obtained solid was then vacuum dried to remove the residual organic solvent, thereby obtaining an organic ligand (400 mg, 80%) as a white solid;

[0087] S5) dissolving an organic ligand (0.100 g, 0.21 mmol) in 50 mL of acetonitrile to obtain an organic ligand solution of tetraphenylethylene monopyridine;

[0088] S6) 4,4-dibromomethylbiphenyl (0.077 g, 0.23 mmol) was dissolved in 30 mL of acetonitrile, and then slowly added dropwise to the organic ligand solution, stirred at 90°C until the reaction stopped, cooled to room temperature, filtered, and an excess of tetrabutylammonium chloride was added to the obtained filtrate to completely precipitate the first precipitate from the solution, and the filter cake was filtered to obtain the filter cake, and the filter cake was dissolved in deionized water, and then filtered and the filtrate was obtained, and an excess of ammonium hexafluorophosphate was added to the filtrate to completely precipitate the second precipitate from the filtrate, and the second precipitate was purified to obtain the fluorescent probe molecule.

[0089] 2. Test of the Example Product, hereinafter C1 represents the fluorescent molecular probe:

[0090] 2.1 Characterization of fluorescent molecular probes using mass spectrometry

[0091] 2.1.1 Using nuclear magnetic resonance to detect the fluorescent molecular probe C1 prepared in Example 1 H NMR spectra, obtained by NMR 1 H NMR spectrum Figure 1 As shown;

[0092] 1 H NMR(500MHz,CD3CN)δ8.69–8.66(d,J=15Hz,8H,H i ),8.18–8.15(d,J=15Hz,8H,H h ),7.74–7.70(dd,J=20Hz,16H,H g,f ),7.53–7.51(d,J=10Hz,8H,Hj ),7.30–7.27(d,J=15Hz,8H,H k ),7.20–7.17(m,12H,H a,d,e ),7.11–7.09(dd,J=10Hz,8H,H b,c ),5.70(s,8H,H m ).ESI-MS(m / z):1769.0518[M-PF6ˉˉ

[0093] ] + (calcd m / z:1768.4995),811.9007[M-2PF6] 2+ (calcd m / z:811.7676),492.8546

[0094] ˉˉ

[0095] [M-3PF6] 3+ (calcd m / z:492.8545),333.0748[M-4PF6] 4+ (calcd m / z:333.4017).

[0096] 2.1.2 Electrospray mass spectrometer (ESI-MS) was used to measure the molecular weight and composition of the fluorescent molecular probe C1 obtained in the example, and the mass spectrum of the fluorescent molecular probe C1 was obtained as shown in FIG. Figure 5 As shown in the figure, four signal peaks can be observed, namely m / z = 1769.0518, m / z = 811.9007, m / z = 492.8546 and m / z = 333.0748, which are respectively related to [M-PF6ˉ] + , [M-2PF6ˉ] 2+ , [M-3PF6ˉ] 3+ and [M-4PF6ˉ] 4+ The signal corresponds to that of; According to the charge and mass-to-charge ratio, the molecular weight of the fluorescent molecular probe C1 is 1913 Da, which is consistent with the molecular formula C 100 H 76 F 24 The molecular weight of N4P4 is consistent with the theoretical calculated value.

[0097] 2.1.3 Using nuclear magnetic resonance to detect the organic ligands prepared in the examples 1 H NMR spectra, obtained by NMR 1 H NMR spectrum Figure 2 As shown;

[0098] 1H NMR (500MHz, CDCl3) δ8.64–8.59 (d, J = 25Hz, 4H, H i ),7.50–7.46(d,J=30Hz,4H,H h ),7.46–7.41(d,J=25Hz,4H,H f ),7.18–7.10(m,10H,H a,b,d,e,g ),7.10–7.05(m,4H,H c ).ESI-MS(486.62calcd.For C 36 H 26 N2):m / z 487.2178[M+H + ] + (calcd m / z:487.2174).

[0099] 2.1.4 Electrospray mass spectrometer (ESI-MS) was used to detect the organic ligand prepared in the embodiment, and the mass spectrum of the organic ligand was obtained as shown in Figure 6 shown.

[0100] 2.2 Fluorescence spectrum test of perfluorooctanoic acid (PFOA) using fluorescent molecular probe C1, the steps are as follows:

[0101] T1) adding acetonitrile and deionized water in a container in a volume ratio of 1:9 to prepare a detection solvent;

[0102] T2) Add 5 mL of the detection solvent to the first cuvette, and then add a 10 -4 mol / L perfluorooctanoic acid to prepare 1# control sample;

[0103] T3) Add 5 mL of the detection solvent to the second cuvette, and then add a 10 -5 mol / L fluorescent molecular probe C1, and prepare 2# control sample;

[0104] T3) Take five other cuvettes, add 5 mL of detection solvent to each, and then add 10 -5 mol / L of fluorescent molecular probe C1, and then add perfluorooctanoic acid of corresponding molar concentrations into five cuvettes according to the molar concentration ratios of fluorescent molecular probe C1 to perfluorooctanoic acid of 100:1, 10:1, 1:1, 1:10 and 1:100, respectively, to prepare five test samples;

[0105] T4) Using a fluorescence spectrometer to irradiate two control samples and five test samples, and obtain corresponding fluorescence spectra.

[0106] The fluorescence spectra of the two control samples and five test samples were summarized as follows: Figure 3 shown.

[0107] Fluorescence photos of two control samples and five test samples are shown in Figure 2. Figure 4 shown.

[0108] The above fluorescence spectra were detected at room temperature. Figure 3 As shown, the fluorescence intensities of the 1# control sample and the 2# control sample are close to the baseline. When the molar concentration ratio of the fluorescent molecular probe C1 to perfluorooctanoic acid is 1:1, the fluorescence begins to be significant. As the molar concentration of PFOA increases, the fluorescence emission peak shifts from 580nm to 560nm, accompanied by a sharp increase in fluorescence, indicating that the interaction between the increased PFOA content and the fluorescent molecular probe C1 continues to increase.

[0109] like Figure 4 As shown, when the molar concentration ratio of the photomolecular probe C1 to perfluorooctanoic acid is 1:100, the color of the fluorescence emission changes from orange-yellow to yellow-green, with an obvious fluorescence response phenomenon.

[0110] In summary, the fluorescent probe molecule for detecting perfluorooctanoic acid of the present invention has a ring structure, which can provide space for the tetraphenylethylene group of the luminescent chromophore to combine with the perfluorooctanoic acid molecule to be detected, so that the tetraphenylethylene group after combination becomes a luminescent chromophore and has an obvious fluorescence response within the effective detection concentration range.

[0111] Furthermore, the preparation method of the fluorescent probe molecule proposed in the present invention obtains tetraphenylethylene monopyridine through a coupling reaction, and obtains the fluorescent probe molecule through a dehalogenation reaction and anion replacement, which provides a new process path for synthesizing fluorescent probes for detecting PFOA.

[0112] Furthermore, the method for detecting perfluorooctanoic acid using fluorescent probe molecules proposed in the present invention has a low dosage of fluorescent probe molecules and has obvious fluorescent response phenomenon and good sensitivity.

[0113] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A fluorescent probe molecule for detecting perfluorooctanoic acid, characterized in that: The fluorescent probe molecule includes a benzylbiphenyl group connected to a tetraphenylethylene group; The fluorescent probe molecule is in a hexagonal ring structure, and the tetraphenylethylene groups distributed in the ring structure of the fluorescent probe molecule can combine with perfluorooctanoic acid and generate fluorescence, and the tetraphenylethylene groups are luminescent chromophores; The molecular formula of the fluorescent probe molecule is C 100 H 76 F 24 N4P4.

2. The fluorescent probe molecule for detecting perfluorooctanoic acid according to claim 1, characterized in that: A plurality of luminescent chromophores are centrally and symmetrically distributed in the ring structure.

3. A method for preparing a fluorescent probe molecule, characterized in that: The method for preparing the fluorescent probe molecule for detecting perfluorooctanoic acid according to claim 1 or 2 comprises the following steps: S1) adding 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) and 4-pyridineboric acid to a stirred reaction vessel, respectively, and then adding N,N-dimethylformamide solution, and dissolving N,N-dimethylformamide uniformly to prepare a mixed solution; S2) adding an alkaline agent to the mixed solution, placing a magnetic bar, adding a catalyst, and repeatedly evacuating and filling with nitrogen three times to obtain a reaction solution; S3) Under nitrogen protection, the reaction temperature of the reaction solution is controlled, and the reaction solution is stirred until the coupling reaction stops, and then cooled to room temperature, the reaction solution is filtered, and the filtrate is taken and the remaining N,N-dimethylformamide is removed by rotary evaporation to obtain a crude product; S4) using neutral Al2O3 as the stationary phase and a mixture of dichloromethane and petroleum ether as the eluent, purifying the crude product by column chromatography, then removing the organic solvent by rotary evaporation, and then vacuum drying the obtained solid to remove the residual organic solvent, thereby obtaining an organic ligand of tetraphenylethylene monopyridine; S5) dissolving the organic ligand in acetonitrile to obtain an organic ligand solution; S6) dissolving 4,4-dibromomethylbiphenyl in acetonitrile, and then slowly dropping it into the organic ligand solution, controlling the reaction temperature, stirring until the dehalogenation reaction stops, cooling to room temperature, filtering with suction, adding an excess of a first anion displacer to the obtained filtrate, so that the solution completely precipitates a first precipitate, filtering with suction to obtain a filter cake, dissolving the filter cake in deionized water, filtering with suction to obtain a filtrate, and then adding an excess of a second anion displacer to the filtrate, so that the filtrate completely precipitates a second precipitate, purifying the second precipitate, and obtaining the fluorescent probe molecule.

4. The method for preparing the fluorescent probe molecule according to claim 3, characterized in that: In step S2), the catalyst is tetrakistriphenylphosphine palladium.

5. The method for preparing the fluorescent probe molecule according to claim 3, characterized in that: In step S2), the alkaline agent is potassium carbonate dissolved in deionized water, and the molar ratio of the alkaline agent to 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) is (4-8):

1.

6. The method for preparing the fluorescent probe molecule according to claim 3, characterized in that: In steps S1) to S2), the molar ratio of 4,4'-(2,2-diphenylethylene-1,1-diyl)bis(bromobenzene) to 4-pyridineboronic acid is 1:(2-3).

7. The method for preparing the fluorescent probe molecule according to claim 3, characterized in that: The reaction temperature of step S3) is 90-110°C, and the reaction temperature of step S6) is 70-90°C; In step S4), the volume ratio of dichloromethane and petroleum ether contained in the eluent is 3:

1.

8. The method for preparing the fluorescent probe molecule according to claim 3, characterized in that: In step S6), the first anion displacer is tetrabutylammonium chloride or tetrabutylammonium iodide, and the second anion displacer is ammonium hexafluorophosphate.

9. A method for detecting perfluorooctanoic acid using a fluorescent probe molecule, characterized in that: The fluorescent probe molecule prepared by the method for preparing the fluorescent probe molecule according to any one of claims 4 to 7 comprises the following steps: T1) adding acetonitrile and deionized water in a container at a volume ratio of 1:9 to prepare a detection solvent; T2) Add 5 mL of detection solvent to a cuvette, and then add 10 -4 mol / L perfluorooctanoic acid to prepare a first control sample; T3) Add 5 mL of the detection solvent to the second cuvette, and then add a 10 -5 mol / L of fluorescent molecular probe to prepare a second control sample; T3) Take five other cuvettes, add 5 mL of detection solvent to each, and then add 10 -5 mol / L of fluorescent molecular probe, and then adding corresponding molar concentrations of perfluorooctanoic acid into five cuvettes according to the molar concentration ratios of the fluorescent molecular probe to perfluorooctanoic acid of 100:1, 10:1, 1:1, 1:10 and 1:100, respectively, to prepare five test samples; T4) Using a fluorescence spectrometer to illuminate the two control samples and each test sample, and obtain corresponding fluorescence spectra.

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