A fluorescent probe molecule for detecting perfluorooctanoic acid and a preparation method and application thereof

Abstract

The application 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 has a hexagonal ring structure; the tetraphenyl ethylene group distributed on the ring structure of the fluorescent probe molecule can be combined with perfluorooctanoic acid and generate fluorescence; the tetraphenyl ethylene group is a luminescent chromophore; and the molecular general formula of the fluorescent probe molecule is C 100 H 76 F 24 N4P4. The ring structure provides space for the combination of the tetraphenyl ethylene group and the perfluorooctanoic acid molecule, so that the combined tetraphenyl ethylene group becomes a luminescent chromophore and has obvious fluorescence response. The application obtains tetraphenyl ethylene monopyridine through a coupling reaction, and prepares the fluorescent probe molecule through a dehalogenation reaction and an anion replacement, thereby providing a new synthesis path. The application is used for detecting perfluorooctanoic acid and has good detection sensitivity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pollutant detection, and particularly relates to a fluorescent probe molecule for detecting perfluorooctanoic acid as well as a preparation method and application thereof. BACKGROUND

[0002] Perfluorooctanoic acid (PFOA) is widely used in the fields of textiles, semiconductors, nano-coatings, fire-fighting foams, medical devices, etc. due to its high physical and chemical stability, strong hydrophobic and oleophobicity, and high surface activity. However, PFOA has environmental persistence, biological accumulation, and long-distance migration, can enter the human body through food, air or water, accumulate in the organs, immune system, endocrine system and reproductive development system of animals and produce toxicity, and seriously threatens the ecological environment and human health, and has been listed as a persistent organic pollutant (POPs).

[0003] At present, the methods for detecting PFOA mainly include high-performance liquid chromatography and gas chromatography-mass spectrometry, both of which have the defects of complex operation, high instrument cost and long detection period, which limits the detection of PFOA.

[0004] The fluorescent 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 a new type of fluorescent probe to realize high-sensitivity and rapid detection of target compounds, especially PFOA. SUMMARY

[0006] In view of the above problems, a first object of the present application is to provide a fluorescent probe molecule for detecting perfluorooctanoic acid to solve the problem of detecting perfluorooctanoic acid.

[0007] Further, a second object of the present application is to provide a preparation method of the fluorescent probe molecule to realize the synthesis of the fluorescent probe molecule for detecting perfluorooctanoic acid.

[0008] Further, a third object of the present application is to provide a method for applying perfluorooctanoic acid in an acetonitrile aqueous solution of the fluorescent probe molecule to realize the detection of perfluorooctanoic acid in pollutants.

[0009] To achieve the above objects, the present application adopts the following technical solutions:

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

[0011] The fluorescent probe molecule has a hexagonal ring structure, and the tetraphenylethylene groups distributed on the ring structure of the fluorescent probe molecule can bind with perfluorooctanoic acid and generate fluorescence, and the tetraphenylethylene groups are luminophores;

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

[0013] Preferably, the plurality of luminophores are distributed symmetrically in the center of the ring structure.

[0014] Further, the present application provides a preparation method of a fluorescent probe molecule for preparing the fluorescent probe molecule for detecting perfluorooctanoic acid.

[0015] S1) 4,4'-(2,2-diphenyl ethylene-1,1-diyl) bis(bromobenzene) and 4-pyridine boronic acid are added to a stirred reaction vessel respectively, then N,N-dimethylformamide solution is added and dissolved uniformly to prepare a mixed solution;

[0016] S2) An alkaline agent is added to the mixed solution, a magnet is put in, a catalyst is added, and vacuum is repeatedly pumped and nitrogen is filled three times to prepare a reaction liquid;

[0017] S3) Under the protection of nitrogen, the reaction temperature of the reaction liquid is controlled, and stirring is continued until the coupling reaction stops, and then the reaction liquid is cooled to room temperature and filtered, the filtrate is taken and rotary evaporation is performed to remove the remaining N,N-dimethylformamide to prepare a crude product;

[0018] S4) Neutral Al2O3 is used as a stationary phase, and a mixed solution of dichloromethane and petroleum ether is used as an eluent, and column chromatography is used to purify the crude product, and then rotary evaporation is performed to remove the organic solvent, and the obtained solid is vacuum dried to remove the residual organic solvent to prepare an organic ligand of tetraphenylethylene monopyridine;

[0019] S5) The organic ligand is dissolved in acetonitrile to prepare an organic ligand solution;

[0020] S6) 4,4-dibromomethyl biphenyl is dissolved in acetonitrile, and then slowly added to the organic ligand solution, the reaction temperature is controlled, and stirring is continued until the dehalogenation reaction stops, and then the solution is cooled to room temperature and filtered, an excess of a first anion replacement agent is added to the obtained filtrate to completely precipitate a first precipitate, the filtrate is filtered and taken, the filter cake is dissolved in deionized water, and then filtered and taken, and then an excess of a second anion replacement agent is added to the filtrate to completely precipitate a second precipitate, and the second precipitate is purified to prepare the fluorescent probe molecule.

[0021] Preferably, in step S2), the catalyst is tetrakis triphenylphosphine 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-diphenyl ethene-1,1-diyl) bis(bromobenzene) is (4-8):1.

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

[0024] Preferably, the reaction temperature of step S3) is 90-110℃, and the reaction temperature of step S6) is 70-90℃.

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

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

[0027] Further, the present application also proposes a method for detecting perfluorooctanoic acid by using a fluorescent probe molecule, wherein the fluorescent probe molecule is prepared by using the above-mentioned method for preparing a fluorescent probe molecule, and the method comprises the following steps:

[0028] T1) add acetonitrile and deionized water into a container in a volume ratio of 1:9 respectively to configure a detection solvent;

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

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

[0031] T3) take another five cuvettes, add 5mL of the detection solvent into each of the five cuvettes respectively, and then add the fluorescent probe molecule with a concentration of 10 -5 mol / L into each of the five cuvettes respectively, and then add perfluorooctanoic acid with a molar concentration ratio of 100:1, 10:1, 1:1, 1:10 and 1:100 respectively into the five cuvettes to prepare five detection samples;

[0032] T4) irradiate the two control samples and each of the detection samples by using a fluorescence spectrometer, and obtain corresponding fluorescence spectrum graphs.

[0033] The beneficial effects of the technical scheme of the present application are that the fluorescent probe molecule for detecting perfluorooctanoic acid has a ring structure, which can provide a space for the combination of the tetraphenylstyrene group of the light-emitting chromophore and the detected perfluorooctanoic acid molecules, so that the combined tetraphenylstyrene group becomes a light-emitting chromophore and has a significant fluorescence response in the effective detection concentration range.

[0034] Further, the preparation method of the fluorescent probe molecule provided by the present application obtains tetraphenylstyrene monopyridine through a coupling reaction, and obtains the fluorescent probe molecule through dehalogenation reaction and anion replacement, thereby providing a new process path for synthesizing the fluorescent probe for detecting PFOA.

[0035] Further, the method for detecting perfluorooctanoic acid using the fluorescent probe molecule provided by the present application has low fluorescent probe molecule dosage and has a significant fluorescence response phenomenon and good sensitivity. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0038] Figure 3 The fluorescent molecule probe prepared by the embodiment of the present application, when the concentration is 10 -5 M, the fluorescence spectrum chart of the test sample of perfluorooctanoic acid with different molar concentrations is shown in the figure; 1# is the control sample of perfluorooctanoic acid with a concentration of 10 -4 M, 2# is the control sample of the fluorescent molecule probe with a concentration of 10 -5 M, the fluorescence spectrum of the control sample 1# is the horizontal baseline in the figure;

[0039] Figure 4 The fluorescent molecule probe prepared by the embodiment of the present application, when the concentration is 10 -5 M, the fluorescence spectrum chart of the test sample of perfluorooctanoic acid with different molar concentrations is shown in the figure; 1# is the control sample of perfluorooctanoic acid with a concentration of 10

[0040] Figure 5 The ESI-MS spectrum of the fluorescent molecule probe prepared by the embodiment of the present application is shown in the figure;

[0041] Figure 6 The ESI-MS spectrum of the organic ligand prepared by the embodiment of the present application is shown in the figure;

[0042] Wherein, C1 is the fluorescent molecule probe; PFOA is perfluorooctanoic acid, 1# is the control sample 1#, and 2# is the control sample 2#. DETAILED DESCRIPTION

[0043] The technical solutions of the present application are further illustrated below through specific embodiments.

[0044] In the description of the present specification, the description referring to the terms "embodiment", "example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do 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 application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

[0046] A fluorescent probe molecule for detecting perfluorooctanoic acid, the fluorescent probe molecule comprising a tetraphenyl ethylene group and a benzyl biphenyl group connected thereto;

[0047] The fluorescent probe molecule has a hexagonal ring structure, and the tetraphenyl ethylene group distributed on the ring structure of the fluorescent probe molecule can bind with perfluorooctanoic acid and generate fluorescence, and the tetraphenyl ethylene group is a luminescent chromophore;

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

[0049] The benzyl biphenyl group and the tetraphenyl ethylene group of the fluorescent probe molecule for detecting perfluorooctanoic acid according to the present application are connected and form a ring structure, which provides a space for the tetraphenyl ethylene group to bind with the detected perfluorooctanoic acid molecules, so that the tetraphenyl ethylene group becomes a luminescent chromophore after binding and has a significant fluorescence response in an effective detection concentration range. The molecular structure formula of the fluorescent probe molecule is as follows:

[0050]

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

[0052] The centrally symmetric distribution structure of the plurality of luminescent chromophores makes the fluorescent probe molecule more easily aggregate in an acetonitrile aqueous solution containing perfluorooctanoic acid, so that the fluorescence effect is enhanced and the detection sensitivity is improved.

[0053] Further, the application provides a preparation method of the fluorescent probe molecule.

[0054] S1) adding 4,4'-(2,2-diphenyl ethene-1,1-diyl) bis(bromobenzene) and 4-pyridine boronic acid into a stirring reaction vessel respectively, then adding N,N-dimethylformamide solution and dissolving the N,N-dimethylformamide uniformly to obtain a mixed solution;

[0055] S2) adding a basic agent into the mixed solution, putting a magnetic stirrer, adding a catalyst, repeatedly vacuumizing and filling nitrogen three times to obtain a reaction solution;

[0056] S3) controlling the reaction temperature of the reaction solution under nitrogen protection, stirring until the coupling reaction stops, then cooling to room temperature, vacuum filtering the reaction solution, taking the filtrate and rotary evaporating to remove the residual N,N-dimethylformamide to obtain a crude product;

[0057] S4) purifying the crude product by column chromatography with neutral Al2O3 as a stationary phase and a mixed solution of dichloromethane and petroleum ether as an eluent, then rotary evaporating to remove the organic solvent, and vacuum drying the obtained solid to remove the residual organic solvent to obtain the organic ligand of tetraphenyl ethene monopyridine;

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

[0059] S6) dissolving 4,4-dibromomethyl biphenyl in acetonitrile, then slowly adding it into the organic ligand solution, controlling the reaction temperature, stirring until the dehalogenation reaction stops, cooling to room temperature, then vacuum filtering, adding an excess of a first anion replacement agent into the obtained filtrate to make the solution completely precipitate a first precipitate, vacuum filtering and taking the filter cake, dissolving the filter cake in deionized water, vacuum filtering and taking the filtrate, then adding an excess of a second anion replacement agent into the filtrate to make the filtrate completely precipitate a second precipitate, purifying the second precipitate to obtain the fluorescent probe molecule.

[0060] The preparation method of the fluorescent probe molecule of the application obtains tetraphenyl ethene monopyridine through the coupling reaction of 4,4'-(2,2-diphenyl ethene-1,1-diyl) bis(bromobenzene) and 4-pyridine boronic acid, uses the tetraphenyl ethene monopyridine as the organic ligand, makes the organic ligand and 4,4-dibromomethyl biphenyl undergo dehalogenation reaction, and then through anion replacement and purification, obtains the fluorescent probe molecule with a ring structure.

[0061] Preferably, in step S2), the catalyst is tetrakis triphenyl phosphine palladium.

[0062] Through the catalytic coupling reaction of tetrakis triphenyl phosphine palladium, the output rate of the organic ligand of tetraphenyl ethene monopyridine is improved.

[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-diphenyl ethene-1,1-diyl) bis(bromobenzene) is (4-8):1.

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

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

[0066] Preferably, the reaction temperature of step S3) is 90-110℃, and the reaction temperature of step S6) is 70-90℃.

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

[0068] The chemical reaction formula of the tetraphenyl ethene 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 replacement agent is tetrabutylammonium chloride or tetrabutylammonium iodide, and the second anion replacement agent is ammonium hexafluorophosphate.

[0073] The first anion replacement agent is used to replace the chloride ions introduced during the reaction, and the second anion replacement agent ammonium hexafluorophosphate is used to precipitate the fluorescent molecular probe from the filtrate, so as to improve the purity and yield of the prepared fluorescent molecular probe.

[0074] Further, the present application also provides a method for detecting perfluorooctanoic acid using a fluorescent probe molecule, wherein the fluorescent probe molecule is prepared by using the above-mentioned preparation method of the fluorescent probe molecule, and the method comprises the following steps:

[0075] T1) Add acetonitrile and deionized water in a volume ratio of 1:9 into a container respectively to configure a detection solvent;

[0076] T2) Add 5mL of the detection solvent into a cuvette, and then add 10 -4The first control sample was prepared using perfluorooctanoic acid at a concentration of mol / L.

[0077] T3) Add 5 mL of the detection solvent to the second cuvette, then add a 10% concentration... -5 A second control sample was prepared using a mol / L fluorescent molecular probe.

[0078] T3) Take five more cuvettes, add 5 mL of the detection solvent to each, and then add 10 mL of the solution to each. -5 Five mol / L fluorescent molecular probes were prepared by adding perfluorooctanoic acid (PFOA) to five cuvettes at molar concentrations of 100:1, 10:1, 1:1, 1:10, and 1:100, respectively, to obtain five test samples.

[0079] T4) Irradiate the two control samples and each test sample with a fluorescence spectrometer and obtain the corresponding fluorescence spectra.

[0080] The above fluorescence spectroscopy detections were performed at room temperature, such as... Figure 3 As shown in the figure, C1 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. Fluorescence becomes significant when the molar concentration ratio of fluorescent probe C1 to perfluorooctanoic acid is 1:1. With increasing PFOA molar concentration, the fluorescence emission peak shifts from 580nm to 560nm, accompanied by a sharp increase in fluorescence, indicating that the interaction between the increasing PFOA content and the fluorescent probe C1 is continuously enhanced, exhibiting a significant fluorescence response phenomenon. Figure 4 As shown, when the molar ratio of fluorescent molecular probe C1 to perfluorooctanoic acid is 1:100, the fluorescence emission color changes from orange-yellow to yellow-green, indicating that a concentration of 10... -5 A concentration of mol / L of the fluorescent probe molecule of the present invention can detect concentrations of 10 mol / L. -5 It has a concentration of PFOA above mol / L and good detection sensitivity.

[0081] Example

[0082] 1. Prepare the fluorescent probe molecules of the example according to the following steps:

[0083] S1) 4,4'-(2,2-diphenylvinyl-1,1-diyl)bis(bromobenzene) (1.020 mmol) and 4-pyridineboronic acid (0.326 g, 2.652 mmol) were added separately to a stirred reactor vessel, and then 42 mL of N,N-dimethylformamide solution was added and the N,N-dimethylformamide was dissolved evenly to obtain a mixed solution;

[0084] S2) In the mixed solution, a basic agent was added, a magnetic stirrer was put in, a catalyst, tetrakis triphenyl phosphine palladium (0.141 g, 0.122 mmol) was added, vacuum was repeatedly pumped and nitrogen was filled for three times, and a reaction solution was prepared;

[0085] S3) The reaction solution was stirred at 110°C under nitrogen protection until the reaction stopped, and then cooled to room temperature. The reaction solution was filtered, and the filtrate was obtained and N,N-dimethylformamide was removed by rotary evaporation to obtain a crude product;

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

[0087] S5) The organic ligand (0.100 g, 0.21 mmol) was dissolved in 50 mL of acetonitrile to obtain a solution of the organic ligand in tetraphenyl ethylene monopyridine;

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

[0089] 2. Test of the product prepared in Example 1, hereinafter represented by C1:

[0090] 2.1 Characterization of the fluorescent molecular probe by mass spectrometry

[0091] 2.1.1 The fluorescent molecular probe C1 prepared in Example 1 was detected by nuclear magnetic resonance instrument 1 H NMR spectrum, and the obtained nuclear magnetic resonance 1 H NMR spectrum is shown in Figure 1 ;

[0092] 1 H NMR (500 MHz, CD3CN) δ 8.69-8.66 (d, J = 15 Hz, 8H, H i ), 8.18-8.15 (d, J = 15 Hz, 8H, H h ), 7.74-7.70 (dd, J = 20 Hz, 16H, H g,f ), 7.53-7.51 (d, J = 10 Hz, 8H, Hj ), 7.30-7.27 (d, J = 15 Hz, 8H, H k ), 7.20-7.17 (m, 12H, H a,d,e ), 7.11-7.09 (dd, J = 10 Hz, 8H, H b,c ), 5.70 (s, 8H, H m ). ESI-MS (m / z): 1769.0518 [M-PF6

[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 The molecular weight and composition of the fluorescent molecular probe C1 prepared in the example were determined by using an electrospray mass spectrometer (ESI-MS), and the mass spectrum of the fluorescent molecular probe C1 is shown in Figure 5 , in which four signal peaks of m / z = 1769.0518, m / z = 811.9007, m / z = 492.8546 and m / z = 333.0748 can be observed, which correspond to the signals of [M-PF6 + , [M-2PF6 2+ , [M-3PF6 3+ and [M-4PF6 4+ ]; according to the calculation of the charge and mass-to-charge ratio values, the molecular weight of the fluorescent molecular probe C1 is 1913 Da, which is consistent with the theoretical calculation value of the molecular weight of C 100 H 76 F 24 N4P4.

[0097] 2.1.3 The 1H NMR spectrum of the organic ligand prepared in the example was detected by using a nuclear magnetic resonance instrument, and the obtained nuclear magnetic resonance 1H NMR spectrum is shown in 1 ; 1 Figure 2 ;

[0098] 1 ​H NMR (500 MHz, CDC13) δ 8.64 - 8.59 (d, J = 25 Hz, 4H, H i ), 7.50 - 7.46 (d, J = 30 Hz, 4H, H h ), 7.46 - 7.41 (d, J = 25 Hz, 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 (486.62 calcd. For C 36 H 26 N2): m / z 487.2178 [M+H + ] + (calcd m / z: 487.2174).

[0099] 2.1.4 The organic ligand prepared in the examples was detected by using an electrospray mass spectrometer (ESI-MS), and the mass spectrum of the organic ligand is shown in Figure 6 .

[0100] 2.2 The fluorescence spectrum test of the fluorescent molecular probe C1 detecting perfluorooctanoic acid (PFOA) is as follows:

[0101] T1) Acetonitrile and deionized water were added into a container in a volume ratio of 1:9 to prepare a detection solvent;

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

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

[0104] T3) Five other cuvettes were taken, 5 mL of the detection solvent was added into each of the cuvettes, 10 -5 mol / L of the fluorescent molecular probe C1 was added into each of the cuvettes, and then the corresponding molar concentration of perfluorooctanoic acid was added into each of the cuvettes according to the molar concentration ratio of the fluorescent molecular probe C1 to perfluorooctanoic acid of 100:1, 10:1, 1:1, 1:10 and 1:100 to prepare five detection samples;

[0105] T4) The two control samples and the five detection samples were irradiated by using a fluorescence spectrometer, and the corresponding fluorescence spectrum was obtained.

[0106] The fluorescence spectrum of the two control samples and the five detection samples obtained is shown inFigure 3 As shown.

[0107] The fluorescence photos of two control samples and five detection samples are as shown. Figure 4 As shown.

[0108] The above fluorescence spectrum detection is carried out at room temperature, as shown. Figure 3 The fluorescence intensity of 1# control sample and 2# control sample is close to the baseline, the fluorescence starts to be obvious when the molar concentration ratio of fluorescent molecular probe C1 and perfluorooctanoic acid is 1:1, and with the increase of the molar concentration of PFOA, the emission peak of fluorescence is shifted, the emission peak wavelength is shifted from 580 nm to 560 nm, and accompanied by the sharp enhancement of fluorescence, indicating that the interaction between PFOA with increasing content and fluorescent molecular probe C1 is continuously enhanced.

[0109] As shown. Figure 4 When the molar concentration ratio of light molecular probe C1 and perfluorooctanoic acid is 1:100, the color of fluorescence emission is changed from orange yellow to yellow green, and has obvious fluorescence response phenomenon.

[0110] In summary, the fluorescence probe molecule for detecting perfluorooctanoic acid has a ring structure, which can provide space for the combination of the tetraphenyl ethylene group of the light emitting chromophore and the detected perfluorooctanoic acid molecules, so that the combined tetraphenyl ethylene group becomes a light emitting chromophore, and has obvious fluorescence response in the effective detection concentration range.

[0111] Further, the preparation method of the fluorescence probe molecule provided by the present application obtains tetraphenyl ethylene monopyridine through coupling reaction, and obtains the fluorescence probe molecule through dehalogenation reaction and anion replacement, which provides a new process path for synthesizing the fluorescence probe for detecting PFOA.

[0112] Further, the method for detecting perfluorooctanoic acid using the fluorescence probe molecule provided by the present application has low dosage of fluorescence probe molecule, and has obvious fluorescence response phenomenon and good sensitivity.

[0113] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for explaining the principles of the present application, and cannot be explained as limiting the protection scope of the present application in any way. Based on the explanations herein, other specific embodiments of the present application can be conceived by those skilled in the art without creative labor, and these embodiments will fall within the protection scope of the present application.

Claims

1. A fluorescent probe molecule for detecting perfluorooctanoic acid (PFOA), characterized in that, The fluorescent probe molecule includes a benzyl biphenyl group linked to a tetraphenylethylene group; The fluorescent probe molecule has a hexagonal ring structure. The tetraphenylethylene groups distributed in the ring structure of the fluorescent probe molecule can bind with perfluorooctanoic acid and generate fluorescence. The tetraphenylethylene groups are luminescent chromophores. The general molecular formula of the fluorescent probe molecule is C2 100 H 76 F 24 N4P 4， The molecular structure of the fluorescent probe molecule is as follows: 。 2. The fluorescent probe molecule for detecting perfluorooctanoic acid according to claim 1, characterized in that, Multiple luminescent color groups are symmetrically distributed in the annular structure.

3. A method for preparing a fluorescent probe molecule, characterized in that, The preparation of the fluorescent probe molecule for detecting perfluorooctanoic acid as described in claim 1 or 2 comprises the following steps: S1) Add 4,4'-(2,2-diphenylvinyl-1,1-diyl)bis(bromobenzene) and 4-pyridineboronic acid to a stirred reactor vessel, then add N,N-dimethylformamide solution and dissolve N,N-dimethylformamide evenly to obtain a mixed solution; S2) Add an alkaline agent to the mixed solution, place a magnetic ball, add a catalyst, and repeatedly evacuate and purge with nitrogen three times to obtain a reaction solution; S3) Under nitrogen protection, control the reaction temperature of the reaction solution, stir until the coupling reaction stops, cool to room temperature, filter the reaction solution, take the filtrate and remove the remaining N,N-dimethylformamide by rotary evaporation to obtain the crude product. S4) Using neutral Al2O3 as the stationary phase and a mixture of dichloromethane and petroleum ether 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 dried under vacuum to remove the residual organic solvent, thus obtaining the organic ligand of tetraphenylpyridine. S5) Dissolve the organic ligand in acetonitrile to prepare an organic ligand solution; S6) Dissolve 4,4-dibromomethylbiphenyl in acetonitrile, then slowly add it dropwise to the organic ligand solution, control the reaction temperature, stir until the dehalogenation reaction stops, cool to room temperature, filter, add excess first anion exchanger to the obtained filtrate to completely precipitate the first precipitate, filter the filter cake, dissolve the filter cake in deionized water, filter and collect the filtrate, then add excess second anion exchanger to the filtrate to completely precipitate the second precipitate, purify the second precipitate to obtain the fluorescent probe molecule; In step S6), the first anion exchanger is tetrabutylammonium chloride or tetrabutylammonium iodide, and the second anion exchanger is ammonium hexafluorophosphate.

4. The method for preparing the fluorescent probe molecule according to claim 3, characterized in that, In step S2), the catalyst is tetratriphenylphosphine 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 for step S3) is 90-110℃, and the reaction temperature for step S6) is 70-90℃; In step S4), the eluent contains dichloromethane and petroleum ether in a volume ratio of 3:

1.

8. A method for detecting perfluorooctanoic acid using fluorescent probe molecules, characterized in that, The fluorescent probe molecule prepared using the preparation method of the fluorescent probe molecule according to any one of claims 4-7 includes the following steps: T1) Add acetonitrile and deionized water to a container at a volume ratio of 1:9 to prepare the detection solvent; T2) Add 5 mL of the detection solvent to a cuvette, then add a 10% concentration... -4 The first control sample was prepared using perfluorooctanoic acid at a concentration of mol / L. T3) Add 5 mL of the detection solvent to the second cuvette, then add a 10% concentration... -5 A second control sample was prepared using a mol / L fluorescent molecular probe. T3) Take five more cuvettes, add 5 mL of the detection solvent to each, and then add 10 mL of the solution to each. -5 Five mol / L fluorescent molecular probes were prepared by adding perfluorooctanoic acid (PFOA) to five cuvettes at molar concentrations of 100:1, 10:1, 1:1, 1:10, and 1:100, respectively, to obtain five test samples. T4) Irradiate the two control samples and each test sample with a fluorescence spectrometer and obtain the corresponding fluorescence spectra.

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