AIE type cationic conjugated polymer, preparation method and application

Abstract

According to the AIE type cationic conjugated polymer, the preparation method and the application provided by the invention, a functionalized tetraphenyl ethylene structure is used as a unit of a donor structure, and emission of different wavelengths is realized by adjusting an acceptor structure. The AIE type cationic conjugated polymer is used as an open type probe, the problem of aggregation fluorescence quenching of a traditional conjugated polymer probe can be solved, and the color of the fluorescent probe is changed from dark to bright. The AIE type cationic conjugated polymer disclosed by the invention has abundant cationic structures and hydrophobic alkyl chains, can more efficiently capture a target object under the cooperation of electrostatic interaction and hydrophobic interaction, and has a huge potential of realizing high-sensitivity and high-accuracy detection on the target object.

Description

Technical Field

[0001] The invention relates to the technical field of fluorescent probes, and in particular to an AIE type cationic conjugated polymer, a preparation method and application thereof. Background Art

[0002] The development of conjugated polymers began in the 1960s. It is a class of polymers with alternating single and double bonds, usually composed of donor-acceptor structures, which gives them unique optoelectronic properties. Conjugated polymers usually have significant light absorption and emission properties, and can produce fluorescence and phosphorescence in the visible and ultraviolet regions. Some conjugated polymers, such as polyaniline and polythiophene, can exhibit semiconductor behavior and even have conductivity under certain conditions, making them widely used in electronic devices.

[0003] The luminescent properties of conjugated polymers make them useful as probes for the detection of specific targets. Due to their unique delocalized π-bond structure, they have a "molecular wire" effect, that is, when any fluorescent group in the polymer interacts with the target, it can trigger the response of all groups on the main chain, thereby amplifying the response signal exponentially and improving the detection sensitivity.

[0004] However, like traditional fluorescent probes, conjugated polymers also have the problem of aggregation quenching fluorescence, which in turn also affects their own luminescence properties. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides an AIE type cationic conjugated polymer, a preparation method and an application thereof, so as to solve the problem of aggregation quenching of fluorescence of fluorescent probes in the prior art.

[0006] The specific content of the invention is as follows: In a first aspect, the present invention provides an AIE type cationic conjugated polymer, wherein the AIE type cationic conjugated polymer has a structural formula shown in Formula I:

[0007] Formula I Wherein, R is selected from any of the following structures: .

[0008] In a second aspect, the present invention provides a method for preparing the AIE type cationic conjugated polymer according to the first aspect, the preparation method comprising the following steps: Step 1, mixing [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene, cesium carbonate and anhydrous acetone solution to form a first solution; mixing 3-chloro-1-(N,N-dimethyl)propylamine and N,N-dimethylformamide solution to form a second solution; Step 2, mixing the first solution and the second solution, placing the mixture at 45° C. to 120° C., reacting the mixture for 6 h to 12 h, and subjecting the obtained product to first separation and purification to obtain a first monomer; Step 3, mixing the first monomer, the acceptor fluorophore R and the toluene solution to form a third solution; adding the potassium carbonate solution to ultrapure water to form a fourth solution; Step 4, the third solution and the fourth solution are mixed, and after degassing, tetrakis(triphenylphosphine)palladium is added, and the mixture is placed at 60° C. to 120° C. for reaction for 6 h to 48 h. The obtained product is subjected to a second separation and purification to obtain a precursor polymer CPs; Step 5, mixing the precursor polymer CPs, (3-bromopropyl)trimethylammonium bromide and a tetrahydrofuran / methanol mixture, and reacting at 45°C to 80°C for 12 h to 48 h, and subjecting the obtained product to a third separation and purification to obtain an AIE-type cationic conjugated polymer AIE-CPs; Wherein, the acceptor fluorophore R has any of the following structures: .

[0009] Optionally, in step 1, the usage ratio of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene, cesium carbonate, and anhydrous acetone solution is (0.1-1.0) g: (0.1-1.2) g: (25-100) mL; and / or The usage ratio of the 3-chloro-1-(N,N-dimethyl)propylamine to N,N-dimethylformamide is (0.1-1.2) g: (10-100) mL.

[0010] Optionally, in step 2, the first separation and purification comprises: The organic solvent in the obtained product is removed by a rotary evaporator, and then a saturated sodium chloride aqueous solution and dichloromethane are added to extract the organic phase; The obtained organic phase is dried over anhydrous sodium sulfate, and then the organic solvent is removed by rotary evaporation, and then eluted by column chromatography to obtain the purified first monomer.

[0011] Optionally, in step 3, the usage ratio of the first monomer, the acceptor fluorophore R, and the toluene solution is (0.1-1.0) g: (0.05-0.5) g: (10-100) mL; and / or The dosage ratio of the potassium carbonate to ultrapure water is (0.5-5.0) g: (1-10) mL.

[0012] Optionally, in step 4, the amount of the tetrakis(triphenylphosphine)palladium catalyst used is 2 to 20 mg / ml 0.005 g to 0.020 g.

[0013] Optionally, in step 4, the second separation and purification comprises: The organic solvent in the obtained product is removed by a rotary evaporator, and then water and dichloromethane are added to extract the organic phase; The obtained organic phase was dried over anhydrous sodium sulfate, and then the organic solvent was removed by rotary evaporation to obtain the purified precursor polymer CPs.

[0014] Optionally, in step 5, the tetrahydrofuran / methanol mixed solution is formed by mixing tetrahydrofuran and methanol in equal volumes; and / or The usage ratio of the precursor polymer CPs, (3-bromopropyl)trimethylammonium bromide and tetrahydrofuran / methanol mixed solution is (0.01-0.1) g: (0.05-1.0) g: (10-100) mL.

[0015] Optionally, in step 5, the third separation and purification comprises: After removing tetrahydrofuran and methanol from the obtained product by a rotary evaporator, a methanol solution was added to dissolve the product; The dissolved mixed solution is dialyzed for 1-3 days, and the dialyzed solid is washed three times with dichloromethane and dried to obtain AIE-type cationic conjugated polymer AIE-CPs.

[0016] In a third aspect, the present invention provides an application of an AIE type cationic conjugated polymer, wherein the AIE type cationic conjugated polymer described in the first aspect is applied to a fluorescent probe.

[0017] Compared with the prior art, the present invention has the following advantages: The present invention provides an AIE type cationic conjugated polymer, which uses a functionalized tetraphenylethylene structure as a unit of a donor structure, and realizes emission of different wavelengths by adjusting an acceptor structure. As a type of open-type probe, the AIE type cationic conjugated polymer can overcome the aggregation fluorescence quenching problem of traditional conjugated polymer probes and realize the change of the color of the fluorescent probe from dark to bright. The AIE type cationic conjugated polymer of the present invention has a rich cationic structure and a hydrophobic alkyl chain, and can capture a target more efficiently under the synergy of electrostatic interaction and hydrophobic interaction, and has great potential for realizing high-sensitivity and high-accuracy detection of the target. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 The flowchart of the preparation method of the AIE type cationic conjugated polymer provided by the embodiment of the present invention is shown; Figure 2 The synthesis route of the AIE type cationic conjugated polymer provided in the embodiment of the present invention is shown; Figure 3 The hydrogen nuclear magnetic resonance spectrum of the AIE type cationic conjugated polymer provided by the embodiment of the present invention is shown; Figure 4 The fluorescence intensity characterization diagram of the AIE type cationic conjugated polymer provided by the embodiment of the present invention is shown. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the present invention and its application or use. Based on the embodiments of the present invention, any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts falls within the scope of protection of the present invention. In addition, all other embodiments obtained by ordinary technicians in this field without carrying out creative work belong to the scope of protection of the present invention.

[0021] In the embodiment, no specific experimental steps or conditions are indicated, and the operation or conditions of the conventional experimental steps described in the prior art in this field can be carried out. The reagents used and other instruments that do not indicate the manufacturer are conventional reagent products that can be obtained commercially. In addition, the accompanying drawings are only schematic diagrams of the embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted. Some block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0022] Technologies, methods, and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the description of the present invention.

[0023] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0024] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] The specific implementation contents of the present invention are as follows: In a first aspect, the present invention provides an AIE type cationic conjugated polymer, wherein the AIE type cationic conjugated polymer has a structural formula shown in Formula I:

[0026] Formula I Wherein, R is selected from any of the following structures: .

[0027] In specific implementation, the embodiment of the present invention uses a functionalized tetraphenylethylene structure as a unit of the donor structure, and achieves emission of different wavelengths by adjusting the acceptor structure R. Compared with traditional conjugated polymer fluorescent probes, the AIE-type cationic conjugated polymer provided in the embodiment of the present invention can overcome the aggregation fluorescence quenching (ACQ) problem of traditional conjugated polymers. Due to the introduction of the AIE donor structure unit, the ACQ problem is overcome, and aggregation-induced emission enhancement (AIE) occurs, thereby achieving a change in the color of the fluorescent probe from dark to bright. Compared with traditional cationic conjugated polymer fluorescent probes, the AIE-type cationic conjugated polymer provided in the embodiment of the present invention has a rich cationic structure and hydrophobic alkyl chain that can capture the target more efficiently. High-efficiency capture is due to the mutual synergy of electrostatic interaction and hydrophobic interaction, which promotes the efficient binding of the probe and the target molecule.

[0028] The donor unit used in the polymer provided by the present invention is TPE, which is essentially an AIE molecule, that is, it has aggregation-induced emission characteristics. It can show bright emission enhancement characteristics in the aggregated state, which is different from the weak or no fluorescence emission characteristics of traditional ACQ (aggregation-quenched fluorescence) molecules in the aggregated state. Thus, the problem of fluorescence quenching of traditional fluorescent molecules in the aggregated state can be solved.

[0029] In a second aspect, the present invention provides a method for preparing an AIE type cationic conjugated polymer. Figure 1 The flow chart of the preparation method of the AIE type cationic conjugated polymer provided by the embodiment of the present invention is shown as follows: Figure 1 As shown, the preparation method comprises the following steps: Step 1: Mix [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene, cesium carbonate and anhydrous acetone solution to form a first solution; and mix 3-chloro-1-(N,N-dimethyl)propylamine and N,N-dimethylformamide solution to form a second solution.

[0030] In this step, the usage ratio of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene, cesium carbonate, and anhydrous acetone solution is (0.1-1.0) g: (0.1-1.2) g: (25-100) mL; the usage ratio of 3-chloro-1-(N,N-dimethyl)propylamine and N,N-dimethylformamide is (0.1-1.2) g: (10-100) mL.

[0031] Step 2, mixing the first solution and the second solution, placing the mixture at 45° C. to 120° C., reacting the mixture for 6 h to 12 h, and subjecting the obtained product to first separation and purification to obtain a first monomer; In this step, after the first solution and the second solution are mixed, a substitution reaction is carried out to generate a first monomer; in order to ensure the normal progress of the reaction and avoid the interference of oxygen on the reaction and the generation of impurities, the substitution reaction is carried out in an environment isolated from oxygen, and there is no oxygen in the reaction environment; as an example, in an embodiment of the present invention, the substitution reaction is carried out in a heating reflux manner, after the first solution and the second solution are mixed, nitrogen is introduced, the oxygen in the mixed solution and the container (three-necked flask) is discharged, and then the container containing the mixed solution is placed in a heating reflux device to carry out the substitution reaction.

[0032] In some embodiments, after the substitution reaction is completed, the process of performing a first separation and purification on the obtained product includes: The organic solvent in the obtained product is removed by a rotary evaporator, and then a saturated sodium chloride aqueous solution and dichloromethane are added to extract the organic phase; The organic phase obtained by extraction is dried over anhydrous sodium sulfate, and the obtained product is filtered and further rotary evaporated to remove the dichloromethane organic solvent, and then eluted by column chromatography to obtain the purified first monomer.

[0033] Step 3, mixing the first monomer, the acceptor fluorophore R and the toluene solution to form a third solution; adding the potassium carbonate solution to ultrapure water to form a fourth solution; In this step, the acceptor fluorophore R has any of the following structures: ; The usage ratio of the first monomer, the acceptor fluorophore R, and the toluene solution in the third solution is (0.1~1.0) g: (0.05~0.5) g: (10~100) mL; the usage ratio of potassium carbonate and ultrapure water is (0.5~5.0) g: (1~10) mL.

[0034] Step 4, the third solution and the fourth solution are mixed, and after degassing, tetrakis(triphenylphosphine)palladium is added, and the mixture is placed at 60° C. to 120° C. for reaction for 6 h to 48 h. The obtained product is subjected to a second separation and purification to obtain a precursor polymer CPs; In this step, the third solution and the fourth solution undergo a polymerization reaction in the presence of a catalyst tetrakis(triphenylphosphine)palladium. After the polymerization reaction is completed, the obtained product is subjected to a second separation and purification to obtain a precursor polymer CPs; the amount of the tetrakis(triphenylphosphine)palladium catalyst used is 2 ~20 mg / ml0.005 g ~0.020 g; in order to ensure the normal progress of the polymerization reaction and avoid the interference of oxygen on the reaction and the generation of impurities, the polymerization reaction is carried out in an oxygen-isolated environment, and there is no oxygen in the reaction environment; as an example, in an embodiment of the present invention, the substitution reaction is carried out in a heating reflux manner, and after the first solution and the second solution are mixed, they are degassed, nitrogen is introduced, and oxygen in the mixed solution and the container (three-necked flask) is discharged, and then the container containing the mixed solution is placed in a heating reflux device to carry out a polymerization reaction.

[0035] In some embodiments, after the polymerization reaction is completed, the process of performing a second separation and purification on the obtained product includes: using a rotary evaporator to remove the organic solvent in the obtained product, and then adding water and dichloromethane to extract the organic phase; after the obtained organic phase is dried over anhydrous sodium sulfate, further rotary evaporation is performed to remove the organic solvent to obtain the purified precursor polymer CPs.

[0036] Step 5: Mix the precursor polymer CPs, (3-bromopropyl)trimethylammonium bromide and tetrahydrofuran / methanol mixture, and react at 45°C~80°C for 12 h~48 h. After the obtained product is subjected to the third separation and purification, an AIE-type cationic conjugated polymer AIE-CPs is obtained.

[0037] In this step, the tetrahydrofuran / methanol mixed solution is a mixed solution formed by mixing tetrahydrofuran and methanol in equal volumes; the amount ratio of the precursor polymer CPs, (3-bromopropyl)trimethylammonium bromide and the tetrahydrofuran / methanol mixed solution is (0.01~0.1) g: (0.05~1.0) g: (10~100) mL.

[0038] In some embodiments, the third separation and purification includes the following process: after removing tetrahydrofuran and methanol from the obtained product by a rotary evaporator, adding a methanol solution to dissolve it; dialyzing the obtained mixed solution for 1-3 days, washing the dialyzed solid three times with dichloromethane, and drying to obtain an AIE-type cationic conjugated polymer AIE-CPs.

[0039] Figure 2The synthesis route of the AIE type cationic conjugated polymer provided in the embodiment of the present invention is shown, combining the above preparation steps and Figure 2 It can be seen that the present invention adopts Suzuki cross-coupling polymerization and post-modification synthesis to design and synthesize a color-adjustable AIE-type cationic conjugated polymer, which exhibits a dispersed state of weak fluorescence emission in a good solvent, and then exhibits an aggregated state of strong fluorescence emission with the addition of a poor solvent or an analyte, so that the luminescent color of the solution changes from dark to bright, thereby realizing the detection of the target. The AIE-type cationic conjugated polymer provided by the present invention is used as an open-type fluorescent probe, which is the first time to use the structure of the regulating receptor and introduce the AIE donor structure to realize an AIE-type cationic conjugated polymer with different emission wavelengths.

[0040] In a third aspect, the present invention provides an application of an AIE type cationic conjugated polymer, wherein the AIE type cationic conjugated polymer provided in the first aspect is applied to prepare a fluorescent probe.

[0041] In specific implementation, based on the AIE type cationic conjugated polymer provided by the present invention, which contains a functionalized tetraphenylethylene donor fluorophore and an R acceptor fluorophore, compared with the traditional conjugated polymer fluorescent probe, the AIE type cationic conjugated polymer provided by the present invention can overcome the aggregation fluorescence quenching (ACQ) problem of the traditional conjugated polymer. Due to the introduction of the AIE donor structural unit, the ACQ problem is overcome, and aggregation-responsive emission enhancement (AIE) occurs, thereby achieving the change of the color of the fluorescent probe from dark to bright. At the same time, the AIE type cationic conjugated polymer provided by the present invention, compared with the traditional cationic conjugated polymer fluorescent probe, its rich cationic structure and hydrophobic alkyl chain can capture the target more efficiently. High-efficiency capture is due to the mutual synergy of electrostatic interaction and hydrophobic interaction, which promotes the efficient combination of the probe and the target molecule. Applying it to the fluorescent probe can overcome the problem of aggregation luminescence quenching of the traditional conjugated polymer, and can give the conjugated polymer probe a novel mechanism of action, so that the conjugated polymer has excellent sensing and imaging properties.

[0042] In order to enable those skilled in the art to more clearly understand the present invention, the AIE type cationic conjugated polymer, preparation method and application of the present invention are now described in detail through the following examples.

[0043] Embodiment 1: 0.1 g of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene and 0.1 g of Cs2CO3 were placed in a three-necked flask, and 25 mL of anhydrous acetone solution was added to obtain a first solution; 0.1 g of 3-chloro-1-(N,N-dimethyl)propylamine was dissolved in 10 mL of anhydrous DMF to obtain a second solution; the second solution was slowly added to the first solution, and nitrogen protection was performed for 6 h at 45°C to carry out a substitution reaction. After the substitution reaction was completed, the organic solvent was removed by a rotary evaporator, saturated NaCl solution and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; and purified by column chromatography to obtain a first monomer.

[0044] 0.1 g of the first monomer and 0.05 g of 4,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)-2,1,3-benzothiadiazole were taken into a three-necked flask, and 10 mL of toluene solution was added to obtain a third solution; 0.5 g of potassium carbonate was mixed with 1 mL of ultrapure water to obtain a fourth solution, and the fourth solution was added to the third solution with a syringe, degassed for 30 minutes, 0.005 g of tetrakis(triphenylphosphine)palladium was added as a catalyst, nitrogen was introduced for 30 minutes, and the polymerization reaction was carried out by heating at 60°C and reflux for 6 hours; after the polymerization reaction was completed, the organic solvent was removed by a rotary evaporator, water and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; the organic solvent was removed by rotary evaporation to obtain a precursor polymer CPs. 0.01 g of CPs, 0.05 g mg of (3-bromopropyl) trimethylammonium bromide and 10 mL of tetrahydrofuran / methanol mixture were mixed and reacted at 45 °C for 12 h. After the reaction, the organic solvent was removed by rotary evaporation. 1 mL of methanol was added to dissolve the mixture and the mixture was transferred to a dialysis bag with a molecular weight of 2.5 kDa and dialyzed for 3 days. After the organic solvent was removed by rotary evaporation, the AIE-type cationic conjugated polymer AIE-CPs (the receptor fluorescent group R in the structural formula I is ).

[0045] Figure 3 The nuclear magnetic resonance hydrogen spectrum of the AIE type cationic conjugated polymer provided in the embodiment of the present invention is shown in FIG. Figure 3 As shown, Figure 3 Proton characteristic peaks shown: 1 H NMR (400 MHz, CH3OD, δ): δ 7.54-6.73 (br,aromatic H), δ 4.08 (br, O-CH2-), δ 3.54 (br, N-CH2-), δ 3.27 (br, N-CH3), δ2.44 (br, -CH2-). This indicates that the synthesized products are AIE-CPs.

[0046] Figure 4 FIG. 4 shows a fluorescence intensity characterization diagram of the AIE type cationic conjugated polymer provided in an embodiment of the present invention, such as Figure 4 As shown in the figure, the horizontal axis is the percentage of the poor solvent tetrahydrofuran (THF), and the vertical axis is the ratio of the fluorescence intensity value to the initial fluorescence intensity value. As the poor solvent THF increases, the aggregation degree of the AIE probe increases and the fluorescence intensity increases.

[0047] Embodiment 2: 0.3 g of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene and 0.3 g of Cs2CO3 were placed in a three-necked flask, and 40 mL of anhydrous acetone solution was added to obtain a first solution; 0.3 g of 3-chloro-1-(N,N-dimethyl)propylamine was dissolved in 30 mL of anhydrous DMF to obtain a second solution; the second solution was slowly added to the first solution, and nitrogen protection was performed for 8 h at 45°C to carry out a substitution reaction. After the substitution reaction was completed, the organic solvent was removed by a rotary evaporator, saturated NaCl solution and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; and purified by column chromatography to obtain a first monomer.

[0048] 0.3 g of the first monomer and 0.15 g of 1,4-phenylenediboronic acid bis(pinacol) ester were put into a three-necked flask, and 30 mL of toluene solution was added to obtain a third solution; 1.0 g of potassium carbonate was mixed with 2 mL of ultrapure water to obtain a fourth solution, and the fourth solution was added to the third solution with a syringe, degassed for 30 min, 0.008 g of tetrakis(triphenylphosphine)palladium was added as a catalyst, nitrogen was introduced for 30 min, and the polymerization reaction was carried out by heating at 80°C and reflux for 18 h; after the polymerization reaction was completed, the organic solvent was removed by a rotary evaporator, water and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; the organic solvent was removed by rotary evaporation to obtain a precursor polymer CPs. 0.03 g of CPs, 0.15 g mg of (3-bromopropyl) trimethylammonium bromide and 30 mL of tetrahydrofuran / methanol mixture were mixed and reacted at 50 °C for 18 h. After the reaction, the organic solvent was removed by rotary evaporation. 1 mL of methanol was added to dissolve the mixture and the mixture was transferred to a dialysis bag with a molecular weight of 2.5 kDa and dialyzed for 3 days. After the organic solvent was removed by rotary evaporation, the AIE-type cationic conjugated polymer AIE-CPs (the receptor fluorescent group R in the structural formula I is ).

[0049] The nuclear magnetic resonance hydrogen spectrum of the AIE type cationic conjugated polymer obtained in this example is similar to the characterization results in Example 1 ( Figure 3 The H NMR spectrum and Figure 4The fluorescence intensity characterization diagram shown is similar and will not be repeated here.

[0050] Embodiment 3: 0.5 g of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene and 0.6 g of Cs2CO3 were placed in a three-necked flask, and 60 mL of anhydrous acetone solution was added to obtain a first solution; 0.6 g of 3-chloro-1-(N,N-dimethyl)propylamine was dissolved in 50 mL of anhydrous DMF to obtain a second solution; the second solution was slowly added to the first solution, and nitrogen protection was applied at 45°C for 9 h to perform a substitution reaction. After the substitution reaction was completed, the organic solvent was removed by a rotary evaporator, saturated NaCl solution and dichloromethane were added for extraction, the organic phase was taken, dried over anhydrous sodium sulfate, and filtered; and purified by column chromatography to obtain a first monomer.

[0051] 0.5 g of the first monomer and 0.25 g of 4,7-bis[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-thienyl]-2,1,3-benzothiadiazole were put into a three-necked flask, and 50 mL of toluene solution was added to obtain a third solution; 2.0 g of potassium carbonate was mixed with 4 mL of ultrapure water to obtain a fourth solution, and the fourth solution was added to the third solution with a syringe, degassed for 30 min, 0.010 g of tetrakis(triphenylphosphine)palladium was added as a catalyst, nitrogen was introduced for 30 min, and the polymerization reaction was carried out by heating at 95°C and reflux for 24 h; after the polymerization reaction was completed, the organic solvent was removed by a rotary evaporator, water and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; the organic solvent was removed by rotary evaporation to obtain a precursor polymer CPs. 0.05 g of CPs, 0.25 g mg of (3-bromopropyl) trimethylammonium bromide and 50 mL of tetrahydrofuran / methanol mixture were mixed and reacted at 60 ° C for 24 h. After the reaction, the organic solvent was removed by rotary evaporation. 1 mL of methanol was added to dissolve, and the mixture was transferred to a dialysis bag with a molecular weight of 2.5 kDa and dialyzed for 3 days. After the organic solvent was removed by rotary evaporation, the AIE type cationic conjugated polymer AIE-CPs (the receptor fluorescent group R in the structural formula I is ).

[0052] The structural formula of 4,7-bis[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-thienyl]-2,1,3-benzothiadiazole is as follows: .

[0053] The nuclear magnetic resonance hydrogen spectrum of the AIE type cationic conjugated polymer obtained in this example is similar to the characterization results in Example 1 ( Figure 3The H NMR spectrum and Figure 4 The fluorescence intensity characterization diagram shown is similar and will not be repeated here.

[0054] Embodiment 4: 0.8 g of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene and 0.9 g of Cs2CO3 were placed in a three-necked flask, and 80 mL of anhydrous acetone solution was added to obtain a first solution; 0.9 g of 3-chloro-1-(N,N-dimethyl)propylamine was dissolved in 70 mL of anhydrous DMF to obtain a second solution; the second solution was slowly added to the first solution, and nitrogen protection was performed for 10 h at 45°C to carry out a substitution reaction. After the substitution reaction was completed, the organic solvent was removed by a rotary evaporator, saturated NaCl solution and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; and purified by column chromatography to obtain a first monomer.

[0055] 0.8 g of the first monomer and 0.4 g of 1H,5H-phenyl[1,2-c:4,5-c"]bis([1,2,5]thiadiazole)-4,8-bis(boronic acid pinacol ester) were placed in a three-necked flask, and 80 mL of toluene solution was added to obtain a third solution; 3.0 g of potassium carbonate was mixed with 8 mL of ultrapure water to obtain a fourth solution, and the fourth solution was added to the third solution with a syringe, degassed for 30 min, 0.015 g of tetrakis(triphenylphosphine)palladium was added as a catalyst, nitrogen was introduced for 30 min, and the polymerization reaction was carried out by heating at 105°C for 36 h; after the polymerization reaction, the organic solvent was removed by a rotary evaporator, water and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; the organic solvent was removed by rotary evaporation to obtain a precursor polymer CPs. 0.08 g of CPs, 0.4 g of (3-bromopropyl)trimethylammonium bromide and 75 mL of tetrahydrofuran / methanol mixture in equal proportions was mixed and reacted at 65°C for 36 h. After the reaction, the organic solvent was removed by rotary evaporation. 1 mL of methanol was added for dissolution and the mixture was transferred to a dialysis bag with a molecular weight of 2.5 kDa for 3 days. After the organic solvent was removed by rotary evaporation, the AIE-type cationic conjugated polymer AIE-CPs (the receptor fluorescent group R in the structural formula I is ).

[0056] The structural formula of 1H,5H-phenyl[1,2-c:4,5-c"]bis([1,2,5]thiadiazole)-4,8-bis(boronic acid pinacol ester) is as follows: .

[0057] The nuclear magnetic resonance hydrogen spectrum of the AIE type cationic conjugated polymer obtained in this example is similar to the characterization results in Example 1 ( Figure 3The H NMR spectrum and Figure 4 The fluorescence intensity characterization diagram shown is similar and will not be repeated here.

[0058] Embodiment 5: 1.0 g of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene and 1.2 g of Cs2CO3 were placed in a three-necked flask, and 100 mL of anhydrous acetone solution was added to obtain a first solution; 1.2 g of 3-chloro-1-(N,N-dimethyl)propylamine was dissolved in 100 mL of anhydrous DMF to obtain a second solution; the second solution was slowly added to the first solution, and nitrogen was protected for 12 h at 45°C to carry out a substitution reaction. After the substitution reaction was completed, the organic solvent was removed by a rotary evaporator, saturated NaCl solution and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; and column chromatography was used for elution and purification to obtain a first monomer.

[0059] 1.0 g of the first monomer and 0.5 g of 4,7-bis(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophen-2-yl)benzo[c]bis([1,2,5])thiadiazole were put into a three-necked flask, and 100 mL of toluene solution was added to obtain a third solution; 5.0 g of potassium carbonate was mixed with 10 mL of ultrapure water to obtain a fourth solution, and the fourth solution was added to the third solution with a syringe, degassed for 30 min, 0.020 g of tetrakis(triphenylphosphine)palladium was added as a catalyst, nitrogen was introduced for 30 min, and the polymerization reaction was carried out by heating at 120° C. and reflux for 48 h; after the polymerization reaction was completed, the organic solvent was removed by a rotary evaporator, water and dichloromethane were added for extraction, the organic phase was taken, dried with anhydrous sodium sulfate, and filtered; the organic solvent was removed by rotary evaporation to obtain a precursor polymer CPs. 0.1 g of CPs, 0.5 g of (3-bromopropyl)trimethylammonium bromide and 100 mL of tetrahydrofuran / methanol mixture were mixed and reacted at 80°C for 48 h. After the reaction, the organic solvent was removed by rotary evaporation. 1 mL of methanol was added to dissolve the mixture and the mixture was transferred to a dialysis bag with a molecular weight of 2.5 kDa and dialyzed for 3 days. After rotary evaporation to remove the organic solvent, the AIE-type cationic conjugated polymer AIE-CPs (the receptor fluorescent group R in the structural formula I is ).

[0060] The structural formula of 4,7-bis(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophen-2-yl)benzo[c]bis([1,2,5]thiadiazole) is as follows: ; The synthetic route of 4,7-bis(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-yl)benzo[c]bis([1,2,5]thiadiazole) is as follows: ; The nuclear magnetic resonance hydrogen spectrum of the AIE type cationic conjugated polymer obtained in this example is similar to the characterization results in Example 1 ( Figure 3 The H NMR spectrum and Figure 4 The fluorescence intensity characterization diagram shown is similar and will not be repeated here.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0062] For the method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and components involved are not necessarily required by the present invention.

[0063] The above is a detailed introduction to an AIE-type cationic conjugated polymer, preparation method and application provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for a person skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An AIE type cationic conjugated polymer, characterized in that: The AIE type cationic conjugated polymer has a structural formula shown in Formula I: Formula I Wherein, R is selected from any of the following structures: 。 2. A method for preparing the AIE type cationic conjugated polymer according to claim 1, characterized in that: The preparation method comprises the following steps: Step 1, mixing [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene, cesium carbonate and anhydrous acetone solution to form a first solution; mixing 3-chloro-1-(N,N-dimethyl)propylamine and N,N-dimethylformamide solution to form a second solution; Step 2, mixing the first solution and the second solution, placing the mixture at 45° C. to 120° C., reacting the mixture for 6 h to 12 h, and subjecting the obtained product to first separation and purification to obtain a first monomer; Step 3, mixing the first monomer, the acceptor fluorophore R and the toluene solution to form a third solution; adding the potassium carbonate solution into ultrapure water to form a fourth solution; Step 4, the third solution and the fourth solution are mixed, and after degassing, tetrakis(triphenylphosphine)palladium is added, and the mixture is placed at 60° C. to 120° C. for reaction for 6 h to 48 h. The obtained product is subjected to a second separation and purification to obtain a precursor polymer CPs; Step 5, mixing the precursor polymer CPs, (3-bromopropyl)trimethylammonium bromide and a tetrahydrofuran / methanol mixture, and reacting at 45°C to 80°C for 12 h to 48 h, and subjecting the obtained product to a third separation and purification to obtain an AIE-type cationic conjugated polymer AIE-CPs; Wherein, the acceptor fluorophore R has any of the following structures: 。 3. The method for preparing the AIE type cationic conjugated polymer according to claim 2, characterized in that: In step 1, the amount ratio of [1,1-bis(4-bromophenyl)-2,2-bis(4-hydroxyphenyl)]ethylene, cesium carbonate, and anhydrous acetone solution is (0.1-1.0) g: (0.1-1.2) g: (25-100) mL; and / or The usage ratio of the 3-chloro-1-(N,N-dimethyl)propylamine to N,N-dimethylformamide is (0.1-1.2) g: (10-100) mL.

4. The method for preparing the AIE type cationic conjugated polymer according to claim 2, characterized in that: In step 2, the first separation and purification comprises: The organic solvent in the obtained product is removed by a rotary evaporator, and then a saturated sodium chloride aqueous solution and dichloromethane are added to extract the organic phase; The obtained organic phase is dried over anhydrous sodium sulfate, and then the organic solvent is removed by rotary evaporation, and then eluted by column chromatography to obtain the purified first monomer.

5. The method for preparing the AIE type cationic conjugated polymer according to claim 2, characterized in that: In step 3, the usage ratio of the first monomer, the acceptor fluorophore R, and the toluene solution is (0.1-1.0) g: (0.05-0.5) g: (10-100) mL; and / or The usage ratio of potassium carbonate to ultrapure water is (0.5~5.0) g: (1~10) mL.

6. The method for preparing the AIE type cationic conjugated polymer according to claim 2, characterized in that: In step 4, the amount of the tetrakis(triphenylphosphine)palladium catalyst used is 2-20 mg / ml.

7. The method for preparing the AIE type cationic conjugated polymer according to claim 2, characterized in that: In step 4, the second separation and purification comprises: The organic solvent in the obtained product is removed by a rotary evaporator, and then water and dichloromethane are added to extract the organic phase; The obtained organic phase was dried over anhydrous sodium sulfate, and then the organic solvent was removed by rotary evaporation to obtain the purified precursor polymer CPs.

8. The method for preparing the AIE type cationic conjugated polymer according to claim 2, characterized in that: In step 5, the tetrahydrofuran / methanol mixed solution is formed by mixing tetrahydrofuran and methanol in equal volumes; and / or The usage ratio of the precursor polymer CPs, (3-bromopropyl)trimethylammonium bromide and tetrahydrofuran / methanol mixed solution is (0.01-0.1) g: (0.05-1.0) g: (10-100) mL.

9. The method for preparing the AIE type cationic conjugated polymer according to claim 2, characterized in that: In step 5, the third separation and purification comprises: After removing tetrahydrofuran and methanol from the obtained product by a rotary evaporator, a methanol solution was added to dissolve the product; The dissolved mixed solution is dialyzed for 1-3 days, and the dialyzed solid is washed three times with dichloromethane and dried to obtain AIE-type cationic conjugated polymer AIE-CPs.

10. An application of an AIE type cationic conjugated polymer, characterized in that: The AIE type cationic conjugated polymer described in claim 1 is used in a fluorescent probe.

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