Polymerizable imidazolyl ionic liquid monomer as well as preparation method and screening method thereof

Abstract

The invention discloses a polymerizable imidazolyl ionic liquid monomer as well as a preparation method and a screening method thereof, and belongs to the technical field of high polymer material preparation, and the polymerizable imidazolyl ionic liquid monomer is prepared by adopting an alkylation substitution reaction, i.e., reacting N-vinyl imidazole with a monomer; the monomer is a halogenated organic matter and is bromoethane, bromobutane, bromodecane, ethyl chloropropionate, methyl chloroacetate, benzyl chloride, vinyl benzyl chloride, chloroethyl methyl ether, chloroacetamide, beta-cyclodextrin and 3-chloropropane sulfonic acid. And the polymerizable imidazolyl ionic liquid monomer is screened. The selected polymerizable imidazolyl ionic liquid monomer contains vinyl, and the monomers can be subjected to polymerization reaction through carbon-carbon double bonds; and secondly, the selected monomer can generate multiple affinity interactions such as static electricity, hydrogen bond, pi-pi and hydrophobic interaction with the target protein, so that the affinity with the protein is improved, and the target protein is stabilized.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer material preparation, and particularly relates to a polymerizable imidazolium-based ionic liquid monomer, a preparation method thereof, and a screening method thereof. Background Art

[0002] Western blotting is a technique widely used in biochemistry for detecting and quantifying specific proteins in complex mixtures. The success of this technique depends on the stability, solubility of proteins, and efficient regulation of molecular interactions. Ionic liquids (ILs) are organic molten salts composed of anions and cations and are liquid at room temperature. They have multiple advantages such as adjustable anion and cation structures, strong biological activity, high stability, and good solubility. It has been found that ionic liquids containing chaotropic cations and affinity anions carefully designed according to the Hofmeister series can better stabilize biological macromolecules. In Western blotting, the unique ionic properties of ILs can enhance the solubility of hydrophobic proteins, reduce aggregation or precipitation, and thus improve protein solubility and stability; imidazolium-based ionic liquids, due to their unique structural characteristics, have diverse interaction modes with proteins, such as hydrogen bonding, electrostatic interaction, π-π stacking, and host-guest interaction, etc. These multiple interactions make imidazolium-based ILs an ideal tool for regulating protein behavior.

[0003] The research group led by Zhang et al. has done a lot of work in the direction of biomolecular imprinting related to ILs. For example, they synthesized ILs-type "dummy templates" of amino acids to expand the selection of imprinting environments and avoid the leakage of template molecules; modified the surface of the immobilized matrix with ILs-type polypeptide "anchoring points" with multiple functional groups to improve the effective immobilization and adsorption recognition ability of template polypeptides; and designed various ILs-type functional monomers, crosslinkers, and emulsifiers to stabilize the structural stability of template polypeptides and template proteins, etc. Qian et al. designed and developed a high-performance protein imprinting material based on a polymerizable imidazolium-based ionic liquid macromonomer (MFM) for the specific recognition of bovine serum albumin (BSA). Through reversible addition-fragmentation chain transfer (RAFT) polymerization, an MFM with both functional imidazole groups and crosslinkable zwitterionic fragments was designed and developed, and its stabilizing effect on BSA was confirmed by circular dichroism spectroscopy; introducing this polyionic liquid macromonomer into the imprinting system, the prepared protein imprinting material has good selective recognition performance, and the corresponding imprinting factor is 4.02, solving the problem of insufficient stability and specificity of small molecule monomers. Based on this, introducing polymerizable imidazolium-based ionic liquids into the imprinting system is expected to achieve accurate imprinting of biological macromolecules such as proteins and improve selective recognition performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a polymerizable imidazolium-based ionic liquid monomer, a preparation method thereof, and a screening method thereof. To achieve the above object, the present invention provides a preparation method of a polymerizable imidazolium ionic liquid monomer, which adopts an alkylation substitution reaction, that is, N-vinylimidazole is used to react with a monomer to prepare a polymerizable imidazolium ionic liquid monomer; the preparation process of the polymerizable imidazolium ionic liquid monomer is as follows: ; wherein, X is the monomer.

[0005] Preferably, the monomer is a halogenated organic compound, including ethyl bromide, n-butyl bromide, decyl bromide, ethyl chloroacetate, methyl chloroacetate, benzyl chloride, vinylbenzyl chloride, chloroethyl methyl ether, chloroacetamide, β-cyclodextrin, and 3-chloropropanesulfonic acid; Preferably, the polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with ethyl bromide is 1-vinyl-3-ethylimidazolium bromide (VVEI) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with n-butyl bromide is 1-vinyl-3-n-butylimidazolium bromide (VBEI) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with decyl bromide is 1-vinyl-3-n-decylimidazolium bromide (VDEI) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with ethyl chloroacetate is 1-vinyl-3-ethylpropionateimidazolium chloride (VEPI) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with methyl chloroacetate is 1-vinyl-3-methylacetateimidazolium chloride (VMAI) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with benzyl chloride is 1-vinyl-3-benzylimidazolium chloride (VBZIM) liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with vinylbenzyl chloride is 1-vinyl-3-styrylimidazolium chloride (PVIM) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with chloroethyl methyl ether is 1-vinyl-3-ethyl methyl ether imidazolium chloride (VEMEI) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with chloroacetamide is 1-vinyl-3-acetamidoimidazolium chloride (VIMA) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with 3-chloropropanesulfonic acid is 1-vinyl-3-propanesulfonic acid imidazolium chloride (VSPIM) ionic liquid monomer, and the preparation schematic diagram is as follows: ; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with β-cyclodextrin is tosylated 1-vinyl-β-cyclodextrin imidazole (VIMCDs) ionic liquid monomer.

[0006] Preferably, it includes the following steps: After mixing N-vinylimidazole with the monomer, heat it to 70 °C and reflux, then wash and dry it with a detergent. The monomer includes any one of bromoethane, bromobutane, and bromodecane. The molar ratio of N-vinylimidazole to the monomer is 1:(1 - 3.2). The detergent is ethyl acetate, the reflux time is 24 h, and the drying temperature is 60 - 70 °C.

[0007] Preferably, it includes the following steps: After mixing N-vinylimidazole with the monomer in a solvent, extract it with an extractant and then lyophilize it. The monomer includes any one of ethyl chloroacetate, methyl chloroacetate, benzyl chloride, vinylbenzyl chloride, chloroethyl methyl ether, and chloroacetamide. The molar ratio of N-vinylimidazole to the monomer is 1:(0.70 - 1.2). The solvent is a mixed solution of ethyl acetate and water or a mixed solution of ethanol and water, and the dissolution reaction time is 24 h.

[0008] Preferably, the preparation method of the cyclodextrin imidazole ionic liquid monomer is as follows: S1. Dissolve β-cyclodextrin in deionized water, and dropwise add an aqueous solution of sodium hydroxide and an acetonitrile solution of tosyl chloride thereto. After stirring at 23 °C and 800 rpm for 2 hours, remove the precipitate by suction filtration, and refrigerate the filtrate overnight at 4 °C. Recover the precipitated tosylated-β-cyclodextrin by suction filtration; the mass-volume ratio of β-cyclodextrin:deionized water:sodium hydroxide:water:tosyl chloride:acetonitrile is 6 g:0.05 L:0.66 g:0.002 L:1 g:0.003 L; S2. Dissolve tosylated-β-cyclodextrin in a mixed solution of vinylimidazole and N,N-dimethylformamide, and react at 75 °C for 4 h under a N2 atmosphere; after cooling to ambient temperature, precipitate the crude product by using acetone, then filter, and dry overnight in a vacuum oven at 50 °C to obtain tosylated 1-vinyl-β-cyclodextrin imidazole ionic liquid; the mass-volume ratio of tosylated-β-cyclodextrin:1-vinylimidazole:N,N-dimethylformamide:acetone is 6.45 g:0.002 L:0.015 L:0.07 L. The preparation schematic diagram is as follows: ; The present invention also provides a polymerizable imidazolium-based ionic liquid monomer prepared by the preparation method of the above-mentioned polymerizable imidazolium-based ionic liquid monomer.

[0009] The present invention also discloses a screening method for a polymerizable imidazolium-based ionic liquid monomer, comprising the following steps: (1) Study on the interaction energy between a protein and an imidazolium-based ionic liquid monomer Calculate the interaction energy between the polymerizable imidazolium-based ionic liquid monomer and the template molecule of the protein in the aqueous phase; first, construct the geometric configurations of the template molecule and the polymerizable imidazolium-based ionic liquid monomer by using GaussView05 software, and perform molecular docking on the polypeptide of the optimized template molecule and the polymerizable imidazolium-based ionic liquid monomer by using Autodock software. The docking is run 10 times to realize the docking between the template molecule and the ligand of the polymerizable imidazolium-based ionic liquid monomer; Secondly, with the aid of the Gaussian16 program, optimize the configurations of the polypeptide of the template molecule and the polymerizable imidazolium-based ionic liquid monomer by using the DFT algorithm, the B3LYP / 6-31G basis set, and the DFT-D3 dispersion correction, and calculate the binding free energy between the polymerizable imidazolium-based ionic liquid monomer and the protein; (2) Study on the effect of the imidazolium-based ionic liquid monomer on the secondary structure of the protein Prepare a template protein solution with a concentration of 0.05 mg / mL, and prepare imidazolium ionic liquid monomer solutions respectively. Pipette 3.00 mL of the protein solution into a series of test tubes. According to the different molar ratios of the template molecule to the imidazolium ionic liquid monomer, add an equal volume of the imidazolium ionic liquid monomer solution to the protein. The molar ratios of the template protein to the ionic liquid monomer are 1:0, 1:5, 1:10, 1:15, 1:20, 1:25, 1:50, 1:75, 1:100 respectively. After the prepared protein-ionic liquid monomer mixed solution is incubated at 4°C for 24 h, circular dichroism spectroscopy is performed; all spectroscopy tests are carried out at 25°C, measured using a 1 cm quartz cuvette, the wavelength is set at 190 - 250 nm, the scanning speed is 20 nm / min, the resolution is 0.60 nm, and the background value needs to be deducted before measuring the sample; (3)Study on the effect of imidazolium ionic liquid monomer on the tertiary structure of proteins Prepare a template protein solution with a concentration of 0.05 mg / mL, and prepare imidazolium ionic liquid monomer solutions respectively. Pipette 3.00 mL of the protein solution into a series of test tubes. According to the different molar ratios of the template molecule to the imidazolium ionic liquid monomer, add an equal volume of the imidazolium ionic liquid monomer solution to the protein. The molar concentration ratios of the template protein to the ionic liquid monomer are 1:0, 1:5, 1:10, 1:15, 1:20, 1:25, 1:50, 1:75, 1:100 respectively. After the prepared protein-ionic liquid monomer mixed solution is incubated at room temperature for 24 h, fluorescence spectroscopy is performed; all spectroscopy tests are carried out at 25°C, measured using a 1 cm quartz cuvette, the wavelength is set at 260 - 380 nm, and the background value needs to be deducted before measuring the sample.

[0010] Preferably, in step (1), the calculation formula for the binding free energy between the polymerizable imidazolium ionic liquid monomer and the template protein is: ; In the formula, E 蛋白-可聚合咪唑基离子液体单体 is the potential energy of the template molecule-functional monomer complex in water; E 蛋白 is the potential energy of the template molecule in water; E 可聚合咪唑基离子液体单体 is the potential energy of the polymerizable imidazolium ionic liquid monomer in water.

[0011] Preferably, the protein template molecule is applicable to all proteins, including but not limited to cytochrome C, bovine serum albumin, human serum albumin, ovalbumin.

[0012] Therefore, the present invention adopts the above-mentioned polymerizable imidazolium-based ionic liquid monomer, its preparation method and screening method, and the beneficial effects are as follows: A series of vinylimidazole-based ionic liquid monomers with different side chains are designed and synthesized by the alkyl substitution method, and the law of the stabilizing effect of imidazolium-based ionic liquids on the structure of the target protein is analyzed by combining spectroscopic experiments and quantum mechanics calculation results, so as to effectively screen a series of polymerizable imidazolium-based ionic liquid functional monomers that can stabilize the target protein.

[0013] Next, through the attached drawings and embodiments, the technical solutions of the present invention will be further described in detail. Brief Description of the Drawings

[0014] Figure 1 It is the structural formula of the polymerizable imidazolium-based ionic liquid monomer sample prepared in Examples 1-11 of the present invention; Figure 2 It is the infrared spectrum of the polymerizable imidazolium-based ionic liquid monomer sample prepared in Examples 1-11 of the present invention; Figure 3 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-ethylimidazolium bromide ionic liquid monomer sample prepared in Example 1 of the present invention; Figure 4 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-n-butylimidazolium bromide ionic liquid monomer sample prepared in Example 2 of the present invention; Figure 5 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-n-decylimidazolium bromide ionic liquid monomer sample prepared in Example 3 of the present invention; Figure 6 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-ethyl propionate imidazolium chloride ionic liquid monomer sample prepared in Example 4 of the present invention; Figure 7 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-methyl acetate imidazolium chloride ionic liquid monomer sample prepared in Example 5 of the present invention; Figure 8 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-benzylimidazolium chloride ionic liquid monomer sample prepared in Example 6 of the present invention; Figure 9 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-styrylimidazolium chloride ionic liquid monomer sample prepared in Example 7 of the present invention; Figure 10 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-ethyl methyl ether imidazolium chloride ionic liquid monomer sample prepared in Example 8 of the present invention; Figure 11 It is the nuclear magnetic resonance hydrogen spectrum of the 1-vinyl-3-acetamide imidazolium chloride ionic liquid monomer sample prepared in Example 9 of the present invention; Figure 121H NMR spectrum of the toluenesulfonated 1-vinyl-β-cyclodextrin imidazolium ionic liquid chloride monomer sample prepared in Example 10 of the present invention; Figure 13 1H NMR spectrum of the 1-vinyl-3-propane sulfonic acid imidazole chloride liquid monomer sample prepared in Example 11 of the present invention; Figure 14 Optimized diagram of the results of 11 polymerizable imidazolium-based ionic liquid monomers in Gaussian 16 by the B3LYP / 6-31G basis set and DFT algorithm in Example 11 of the present invention; Figure 15 Optimal binding conformation diagram of the polypeptides of cytochrome C with 11 polymerizable imidazolium-based ionic liquid monomers in Example 12 of the present invention; Figure 16 Binding sites of the interaction between 11 ligands and the polypeptides of cytochrome C in Example 12 of the present invention; Figure 17 Structure diagram and electrostatic potential analysis diagram of the interaction between 11 ligands and the polypeptides of cytochrome C in Example 12 of the present invention; Figure 18 Schematic diagram of the influence of 11 ligands at different concentrations on the secondary structure of Cyt C in Example 13 of the present invention; Figure 19 Diagram of the changes in the internal microenvironment of Cyt C protein by 11 ligands at different concentrations in Example 14 of the present invention. Detailed implementation manners

[0015] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and examples.

[0016] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs.

[0017] The present invention provides a preparation method of a polymerizable imidazolium-based ionic liquid monomer, which adopts an alkylation substitution reaction, that is, using N-vinylimidazole to react with a monomer to prepare a polymerizable imidazolium-based ionic liquid monomer; the preparation process of the polymerizable imidazolium-based ionic liquid monomer is as follows: ; wherein, X is the monomer.

[0018] The monomer is a halogenated organic compound, including bromoethane, bromo-n-butane, bromodecane, ethyl chloroacetate, methyl chloroacetate, benzyl chloride, vinylbenzyl chloride, chloroethyl methyl ether, chloroacetamide, toluenesulfonated β-cyclodextrin, and 3-chloropropane sulfonic acid.

[0019] Example 1 Preparation of 1-vinyl-3-ethylimidazolium bromide ionic liquid monomer: Take 16.43 g (0.20 mol) of N-vinylimidazole and 6.81 g (62.00 mmol) of ethyl bromide, reflux at 70 °C for 24 h, wash three times with ethyl acetate, and obtain the lower-layer light brown product. After drying the product at 60 °C, 1-vinyl-3-ethylimidazolium bromide ionic liquid monomer is obtained.

[0020] Example 2 Preparation of 1-vinyl-3-butylimidazolium bromide ionic liquid monomer: Take 16.43 g (0.20 mol) of N-vinylimidazole and 34.26 g (0.25 mol) of 1-bromobutane, reflux at 70 °C for 24 h, wash three times with ethyl acetate, and obtain the lower-layer light brown product. After drying the product at 60 °C, 1-vinyl-3-butylimidazolium bromide ionic liquid monomer is obtained.

[0021] Example 3 Preparation of 1-vinyl-3-decylimidazolium bromide ionic liquid monomer: Take 16.43 g (0.20 mol) of N-vinylimidazole and 13.81 g (62.00 mmol) of 1-bromodecane, reflux at 70 °C for 24 h, wash three times with ethyl acetate, and obtain the lower-layer light brown product. After drying the product at 60 °C, 1-vinyl-3-decylimidazolium bromide ionic liquid monomer is obtained.

[0022] Example 4 Preparation of 1-vinyl-3-ethyl propionate imidazolium chloride ionic liquid monomer: Take 4.70 g (50.00 mmol) of N-vinylimidazole and 8.53 g (62.00 mmol) of ethyl chloroacetate, dissolve and react in a mixed solution of 10 mL of water and 10 mL of ethyl acetate for 24 h. After the reaction, extract with ethyl acetate, and freeze-dry the aqueous phase solution after extraction to obtain 1-vinyl-3-ethyl propionate imidazolium chloride ionic liquid monomer.

[0023] Example 5 Preparation of 1-vinyl-3-methyl acetate imidazolium chloride ionic liquid monomer: Take 4.10 g (44.00 mmol) of N-vinylimidazole and 6.78 g (62.00 mmol) of methyl chloroacetate, dissolve and react in a mixed solution of 10.00 mL of ethanol and 10.00 mL of water for 24 h. After the reaction, extract with ethyl acetate, and freeze-dry the solution in the aqueous phase after extraction to obtain 1-vinyl-3-methyl acetate imidazolium chloride ionic liquid monomer.

[0024] Example 6 Preparation of 1-vinyl-3-benzylimidazolium chloride ionic liquid monomer: Take 4.10 g (44.00 mmol) of N-vinylimidazole and 7.90 g (62.00 mmol) of benzyl chloride, dissolve them in 10 mL of ethyl acetate, then react in 10.00 mL of ethanol for 24 h. After the reaction, extract with ethyl acetate, and freeze-dry the aqueous solution after extraction to obtain 1-vinyl-3-benzylimidazolium chloride ionic liquid.

[0025] Example 7 Preparation of 1-vinyl-3-styrylimidazolium chloride ionic liquid: Take 4.70 g (50.00 mmol) of N-vinylimidazole and 6.50 g (43.00 mmol) of vinylbenzyl chloride, dissolve them in a mixed solution of 20.00 mL of water and 20.00 mL of ethyl acetate and react for 24 h. After the reaction, extract with ethyl acetate, and freeze-dry the extraction solution to obtain 1-vinyl-3-styrylimidazolium chloride ionic liquid.

[0026] Example 8 Preparation of 1-vinyl-3-ethyl methyl ether imidazolium chloride ionic liquid monomer: Take 4.70 g (50.00 mmol) of N-vinylimidazole and 5.90 g (62.00 mmol) of chloroethyl methyl ether, dissolve them in a mixed solution of 10 mL of water and 10 mL of ethyl acetate and react for 24 h. After the reaction, extract with ethyl acetate, and freeze-dry the extraction solution to obtain 1-vinyl-3-ethyl methyl ether imidazolium chloride ionic liquid monomer.

[0027] Example 9 Preparation of 1-vinyl-3-acetamidoimidazolium chloride ionic liquid monomer: Take 3.10 g (33.00 mmol) of N-vinylimidazole and 2.90 g (31.00 mmol) of chloroacetamide, dissolve them in a mixed solution of 13.00 mL of ethanol and 13.00 mL of water and react for 24 h. After the reaction, extract with ethyl acetate, and freeze-dry the solution after extraction to obtain 1-vinyl-3-acetamidoimidazolium chloride ionic liquid.

[0028] Example 10 S1. Dissolve β-cyclodextrin in deionized water, dropwise add an aqueous solution of sodium hydroxide and an acetonitrile solution of tosyl chloride thereto, stir at 23 °C and 800 rpm for 2 hours, then remove the precipitate by suction filtration, refrigerate the filtrate at 4 °C overnight, and recover the precipitated tosylated-β-cyclodextrin by suction filtration; S2. Sulfonate-β-cyclodextrin is dissolved in a mixed solution of vinylimidazole and N,N-dimethylformamide. Under a N₂ atmosphere, the reaction is carried out at 75 °C for 4 h. After cooling to ambient temperature, the crude product is precipitated by using acetone, then filtered, and dried overnight in a vacuum oven at 50 °C to obtain sulfonated 1-vinyl-β-cyclodextrin imidazole ionic liquid.

[0029] Example 11 Preparation of 1-vinyl-3-propane sulfonic acid imidazole chloride ionic liquid: At 50 °C, VIM (1.88 g, 0.02 mol) is dissolved in 10.00 mL of acetonitrile. Under vigorous magnetic stirring, 1,3-propane sultone (3.66 g, 0.03 mol) is slowly dropped into the reactor using a constant pressure funnel. The mixture is stirred at 50 °C for 24 h to obtain 4.53 g of a white precipitate, which is further purified by washing with a small amount of acetone and freeze-dried by lyophilization to obtain 1-vinyl-3-propane sulfonic acid imidazole chloride ionic liquid.

[0030] The eleven polymerizable imidazolium-based ionic liquid monomer samples prepared in the above Examples 1-11 are sequentially numbered a-k. The structural formulas of the eleven polymerizable imidazolium-based ionic liquid monomer samples are as shown in the attached Figure 1 description. Through detection and analysis, the infrared spectrum scanning results of the eleven polymerizable imidazolium-based ionic liquid monomer samples numbered a-k are as shown in the attached Figure 2 description.

[0031] For Figure 2 the scanning process and analysis results are as follows: The scanning wavelength range is 4000~400 cm -1 , and the spectrum shows that corresponding absorption peaks appear. In the spectrum, there are unsaturated C-H stretching vibrations (3200 - 3000 cm -1 ), C=N stretching vibrations (1571 cm -1 ), C-H out-of-plane rocking bending vibrations (757 cm -1 ), aliphatic hydrocarbon C-H stretching vibrations (2990 cm -1 ), C-skeleton stretching vibrations (1551 cm -1 ) on the imidazole ring of the imidazolium-based ionic liquid, and C=C stretching vibrations (1649 cm -1 ), C-H stretching vibrations (959 cm -1 ) in the olefin connected to the imidazole ring. Due to the presence of CH₂ in-plane rocking vibrations (810 - 720 cm n ) in the chain structure of the -(CH₂) -1), whose vibration decreases with the increase of n, and when there are more than 4 adjacent CH2s, in-plane rocking vibration of CH2 (725 - 715 cm -1 ), so in-plane rocking vibration of CH2 (757 cm -1 ) indicates the successful synthesis of A 1-vinyl-3-ethylimidazolium bromide ionic liquid monomer; in-plane rocking vibration of CH2 (747 cm -1 ) indicates the successful synthesis of B 1-vinyl-3-butylimidazolium bromide ionic liquid monomer; in-plane rocking vibration of CH2 (722 cm -1 ) indicates the successful synthesis of C 1-vinyl-3-decylimidazolium bromide ionic liquid monomer. Among them, C=O stretching vibration of ester group (1730 cm -1 ), C-O-C stretching vibration (1172 cm -1 ), and in-plane rocking vibration of methylene group (757 cm -1 ) indicate the synthesis of D 1-vinyl-3-ethyl propionate imidazolium chloride ionic liquid, and in-plane rocking vibration of methylene group (752 cm -1 ) indicates the synthesis of E 1-vinyl-3-methyl acetate imidazolium chloride ionic liquid. Among them, C-H stretching vibration on the benzene ring (3056 cm -1 ), C-C skeletal vibration (1546 cm -1 , 1454 cm -1 ), and out-of-plane bending vibration of C-H on the monosubstituted benzene ring (711 cm -1 ) indicate the successful synthesis of F 1-vinyl-3-benzylimidazolium chloride; out-of-plane bending vibration of C-H on the meta-disubstituted benzene ring (825 cm -1 ) indicates the successful synthesis of G 1-vinyl-3-styrylimidazolium chloride ionic liquid. Among them, aliphatic ether -C-O-C- stretching vibration (1115 cm -1 ) indicates the successful synthesis of H 1-vinyl-3-ethyl methyl ether imidazolium chloride ionic liquid. Among them, C=O stretching vibration on the amide (1670 cm -1 ), C-N stretching vibration (1404 cm -1 ), N-H stretching vibration (3116 cm -1 ) indicate the successful synthesis of I 1-vinyl-3-acetamide imidazolium chloride ionic liquid. Among them, -OH stretching vibration (3341 cm -1 ), ether group -C-O-C- stretching vibration (1027 cm -1 ), C=O stretching vibration in the ester group (1730 cm -1 ), C-O-C stretching vibration (1280 - 1100 cm -1 ) indicate the successful synthesis of J tosylated 1-vinyl-β-cyclodextrin imidazolium ionic liquid. Among them, -SO3 -Asymmetric stretching vibration (1188 cm -1 ) and -SO3 - symmetric stretching vibration (1048 cm -1 ) indicate the successful synthesis of K 1-vinyl-3-propane sulfonyl chloride imidazole ionic liquid.

[0032] The 1H NMR spectra of the polymerizable imidazolium-based ionic liquid monomer samples prepared in Examples 1-11 are as shown in the attached Figures 3 - 13 description, and the results are as follows: Figure 3 It shows that 1 H NMR (400 MHz, DMSO- d 6) δ 9.75 (s, 1H), 8.30 (s, 1H), 8.05(s, 1H), 7.37 (dd, J = 15.7, 8.7 Hz, 1H), 6.04 (dd, J = 15.7, 2.3 Hz, 1H), 5.44(dd, J = 8.7, 2.4 Hz, 1H), 4.28 (q, J = 7.3 Hz, 1H), 1.47 (t, J = 7.3 Hz, 2H). Figure 4 It shows that 1 H NMR (400 MHz, DMSO- d 6) δ 9.78 (s, 1H), 8.33 (s, 1H), 8.05(s, 1H), 7.38 (dd, J = 15.7, 8.8 Hz, 1H), 6.05 (d, J = 15.6 Hz, 1H), 5.44 (d, J =8.8 Hz, 1H), 4.26 (t, J = 7.2 Hz, 1H), 1.88 – 1.76 (m, 1H), 1.29 (q, J = 7.5 Hz,1H), 0.92 (t, J = 7.4 Hz, 2H). Figure 5 It shows that 1 H NMR (400 MHz, DMSO- d6) δ 9.57 (s, 1H), 8.24 (s, 1H), 7.97(s, 1H), 7.31 (dd, J = 15.6, 8.8 Hz, 1H), 5.98 (d, J = 18.0 Hz, 1H), 5.42 (d, J =2.4 Hz, 1H), 4.20 (t, J = 7.3 Hz, 1H), 1.84 (s, 1H), 1.24 (s, 8H), 0.90 – 0.79(m, 2H). From Figure 6 it can be seen that 1 H NMR (300 MHz, ) δ 9.97 (s, 1H), 8.37 – 8.32 (m, 2H),8.07 (t, J = 1.4 Hz, 1H), 7.77 (d, J = 1.1 Hz, 1H), 7.41 (dd, J = 11.7, 6.6 Hz,1H), 7.24 (dd, J = 11.9, 6.7 Hz, 1H), 7.16, 5.62 (dd, J = 11.9, 1.2 Hz, 1H), 5.50– 5.40 (m, 2H), 4.97 (dd, J = 6.7, 1.2 Hz, 1H), 1.77 (d, J = 5.6 Hz, 3H). Figure 7 It shows that 1 H NMR (400 MHz, DMSO- d 6) δ 9.57 (s, 0H), 8.29 (s, 0H), 7.92(s, 1H), 7.44 (dd, J = 15.6, 8.6 Hz, 1H), 6.02 (d, J = 15.6 Hz, 1H), 5.46 (d, J =8.7 Hz, 1H), 5.22 (s, 1H), 3.42 (s, 1H). Figure 8 It shows that 1 H NMR (300 MHz, ) δ 10.00 (d, J= 1.3 Hz, 1H), 8.31 (t, J = 1.4Hz, 1H), 8.02 (t, J = 1.4 Hz, 1H), 7.50 (dd, J = 5.8, 1.3 Hz, 2H), 7.41 – 7.27(m, 5H), 6.03 (dd, J = 11.7, 1.8 Hz, 1H), 5.51 (s, 2H), 5.40 (dd, J = 6.6, 1.8Hz, 1H). Figure 9 It shows that 1 H NMR (300 MHz, ) δ 9.68 (s, 1H), 8.25 (d, J = 5.0 Hz, 1H),7.96 (s, 1H), 7.56 – 7.43 (m, 4H), 7.38 – 7.28 (m, 2H), 6.75 (dd, J = 13.2, 8.2Hz, 1H), 5.94 (dd, J = 29.1, 12.4 Hz, 2H), 5.46 (s, 2H), 5.31 (d, J = 8.1 Hz,1H). Figure 10 It shows that 1 H NMR(300 MHz, DMSO ) δ 9.90 (s, 1H), 8.38 (d, J = 2.9 Hz,1H), 8.01, 7.45 (dd, J = 11.7, 6.6 Hz, 1H), 6.09 (dd, J = 11.7, 1.8 Hz, 1H), 5.43(dd, J = 6.6, 1.8 Hz, 1H), 4.46 (t, J = 3.7 Hz, 2H), 3.76 (d, J = 3.7 Hz, 2H), 3.29(s, 3H). Figure 11 It shows that 1 H NMR (400 MHz, DMSO- d6) δ 9.58 (s, 1H), 8.27 (s, 0H), 8.10(s, 1H), 7.89 (s, 0H), 7.62 (s, 1H), 7.41 (dd, J = 15.6, 8.8 Hz, 1H), 6.01 (d, J = 15.6 Hz, 1H), 5.44 (d, J = 11.2 Hz, 1H), 5.04 (s, 1H). Figure 12 It shows that 1 H NMR (400 MHz, DMSO-d6) δ 8.15 (s, 1H), 7.98 (s, 4H), 7.62(s, 4H), 7.18 (dd, J = 15.8, 8.9 Hz, 5H), 7.02 (s, 4H), 5.50 (d, J = 15.8 Hz,6H), 4.89 (dd, J = 8.9, 1.4 Hz, 6H), 4.63 (s, 2H), 4.03 (s, 5H), 3.53 - 3.46(m, 16H), 1.89 (s, 3H), 1.80 (s, 2H). Figure 13 It shows that 1 H NMR (400 MHz, DMSO-d6) δ 9.47 (s, 1H), 8.18 (s, 1H), 7.94(s, 1H), 7.29 (dd, J = 15.7, 8.8 Hz, 1H), 5.95 (dd, J = 15.6, 2.2 Hz, 1H),5.41 (dd, J = 8.7, 2.2 Hz, 1H), 4.34 (t, J = 7.0 Hz, 2H), 2.44 (t, J = 7.1Hz, 2H), 2.13 (p, J = 7.0 Hz, 2H). The present invention also discloses a screening method for polymerizable imidazolium-based ionic liquid monomers, comprising the following steps: (1) Study on the interaction energy between proteins and imidazolium-based ionic liquid monomers Calculate the interaction energy between the polymerizable imidazolium-based ionic liquid monomer and the template molecule of the protein in the aqueous phase. First, use the GaussView 05 software to construct the geometric configurations of the template molecule and the polymerizable imidazolium-based ionic liquid monomer. Then, use the Autodock software to perform molecular docking between the polypeptide of the optimized template molecule and the polymerizable imidazolium-based ionic liquid monomer. The docking is run 10 times to achieve the docking between the template molecule and the ligand of the polymerizable imidazolium-based ionic liquid monomer. Secondly, with the help of the Gaussian 16 program, use the DFT algorithm, B3LYP / 6-31G basis set, and DFT-D3 dispersion correction to optimize the configurations of the polypeptide of the template molecule and the polymerizable imidazolium-based ionic liquid monomer, and calculate the binding free energy between the polymerizable imidazolium-based ionic liquid monomer and the protein. (2)Study on the effect of imidazolium-based ionic liquid monomer on the secondary structure of proteins Prepare a template protein solution with a concentration of 0.05 mg / mL, and prepare imidazolium-based ionic liquid monomer solutions respectively. Pipette 3.00 mL of the protein solution into a series of test tubes. According to the different molar ratios of the template molecule to the imidazolium-based ionic liquid monomer, add imidazolium-based ionic liquid monomer solutions with the same volume as the protein. The molar ratios of the template protein to the ionic liquid monomer are 1:0, 1:5, 1:10, 1:15, 1:20, 1:25, 1:50, 1:75, 1:100 respectively. After incubating the prepared protein-ionic liquid monomer mixed solution at 4°C for 24 h, perform circular dichroism spectroscopy tests. All spectroscopy tests are carried out at 25°C, using a 1 cm quartz cuvette for measurement. Set the wavelength to 190 - 250 nm, the scanning speed to 20 nm / min, and the resolution to 0.60 nm. The background value needs to be subtracted before measuring the sample. (3)Study on the effect of imidazolium-based ionic liquid monomer on the tertiary structure of proteins Prepare a template protein solution with a concentration of 0.05 mg / mL, and prepare imidazolium-based ionic liquid monomer solutions respectively. Pipette 3.00 mL of the protein solution into a series of test tubes. According to the different molar ratios of the template molecule to the imidazolium-based ionic liquid monomer, add imidazolium-based ionic liquid monomer solutions with the same volume as the protein. The molar concentration ratios of the template protein to the ionic liquid monomer are 1:0, 1:5, 1:10, 1:15, 1:20, 1:25, 1:50, 1:75, 1:100 respectively. After incubating the prepared protein-ionic liquid monomer mixed solution at room temperature for 24 h, perform fluorescence spectroscopy tests. All spectroscopy tests are carried out at 25°C, using a 1 cm quartz cuvette for measurement. Set the wavelength to 260 - 380 nm. The background value needs to be subtracted before measuring the sample. In step (1), the calculation formula for the binding free energy between the polymerizable imidazolium-based ionic liquid monomer and the protein is: ; In the formula, E 蛋白-可聚合咪唑基离子液体单体 is the potential energy of the template molecule and functional monomer complex in water; E 蛋白 is the potential energy of the template molecule in water; E 可聚合咪唑基离子液体单体 is the potential energy of the polymerizable imidazolium ionic liquid monomer in water.

[0033] The described protein template molecule is applicable to all proteins, including but not limited to cytochrome C, bovine serum albumin, human serum albumin, and ovalbumin.

[0034] In the following examples, the eleven imidazolium ionic liquid monomers prepared above were used as examples for screening, namely: 1-vinyl-3-ethylimidazolium bromide, 1-vinyl-3-n-butylimidazolium bromide, 1-vinyl-3-n-decylimidazolium bromide, 1-vinyl-3-ethyl propionate imidazolium chloride, 1-vinyl-3-methyl acetate imidazolium chloride, 1-vinyl-3-benzylimidazolium chloride, 1-vinyl-3-styrylimidazolium chloride, 1-vinyl-3-ethyl methyl ether imidazolium chloride, 1-vinyl-3-acetamide imidazolium chloride, toluenesulfonated 1-vinyl-β-cyclodextrin imidazole, and 1-vinyl-3-propane sulfonic acid imidazolium chloride monomer. The above polymerizable imidazolium ionic liquid monomers are numbered as ligand a, ligand b, ligand c, ligand d, ligand e, ligand f, ligand g, ligand h, ligand i, ligand j, and ligand k in sequence.

[0035] To screen out the imidazolium ionic liquid monomer that binds most firmly to the template molecule.

[0036] Example 12 In this example, the 11 ligands prepared in Examples 1 - 11 were used to explore the quantum mechanical calculation of the protein-polymeric imidazolium ionic liquid monomer complex.

[0037] With the help of Autodock software, the binding free energy and binding conformation between the polypeptide of cytochrome C and the polymerizable imidazolium ionic liquid monomer were predicted. The 11 polymerizable imidazolium ionic liquid monomers used in the simulation calculation of this example were optimized for their structures in Gaussian16 through the B3LYP / 6-31G basis set and DFT algorithm, as Figure 14 shown. Through preliminary molecular docking calculations, the binding conformations with the optimal binding ability between the polypeptide of cytochrome C and the 11 polymerizable imidazolium ionic liquid monomers were obtained, as Figure 15 shown.

[0038] Using the docking results of the Autodock software, by further borrowing the Gaussian program, the interaction energies ΔG (kcal / mol) between 10 ligands and polypeptides were calculated using the DFT algorithm, B3LYP / 6-31G basis set, DFT-D3 dispersion correction, and BSSE correction, as shown in Table 1.

[0039] Table 1. Predicted interaction energies Δ G between the polypeptides and ligands (kcal / mol) ;

[0040] From the results, ligand b, ligand c, and ligand f have the strongest interactions with the cytochrome C polypeptide, while ligand e has the weakest interaction with the cytochrome C polypeptide. From the calculated binding energies of ligand a, ligand b, ligand c, ligand e, and ligand f with the cytochrome C polypeptide respectively, ligand b, ligand c, and ligand f have the strongest interactions with the cytochrome C polypeptide, while ligand e has the weakest interaction with the cytochrome C polypeptide.

[0041] Electrostatic potential map instructions are attached Figure 17 As shown, the bluer the color, the smaller the charge carried by that part. First, from the structural diagram and the electrostatic potential map, it can be seen that the positively charged small molecules are all around the cytochrome C polypeptide with a smaller charge, indicating that the overall conformational arrangement of the small molecules and the cytochrome C polypeptide molecules is reasonable. Among the 11 systems, in ligand j, due to the hydrophobic cavity of β-cyclodextrin that can specifically encapsulate the hydrophobic region of the polypeptide, the binding energy is the highest; in ligand b, the butane chain length is appropriate, with strong hydrophobic interactions and no significant steric hindrance, so its binding energy with the polypeptide is also strong; compared with ligand b, the decane chain in ligand c is too long, resulting in steric hindrance and partially offsetting the hydrophobic advantage, but the overall still maintains a high binding force; in ligand i, due to its acetamide group that can bind to the polypeptide backbone or side chain through hydrogen bonds, enhancing specificity, but the polar group may reduce the hydrophobic interaction, so the overall effect is weaker than that of the pure alkyl chain; in ligand k, the sulfonic acid group has a strong negative charge and can drive electrostatic binding, but the sulfonic acid hydration layer may weaken the direct contact with the polypeptide, resulting in a slightly weaker binding energy; in ligand d and ligand e, the carbonyl and ether groups may bind to the polypeptide through dipole interactions, but their short chains and strong polarity result in insufficient hydrophobic interactions, and their binding energies are weak; in ligand h, the polar oxygen atom of the ether group may interfere with hydrophobic binding, and there are no strong electrostatic or hydrogen bond sites; in ligand f and ligand g, the rigid benzene ring of the benzyl group leads to an increase in steric hindrance, hindering their close contact with the polypeptide, resulting in ineffective π-π interaction, so their binding energies are the weakest.

[0042] Example 13 In this example, ligands a - k were used to explore their effects on the protein secondary structure CD spectroscopy has been used as a descending technique to examine conformational changes of proteins and peptides in aqueous solution. Far-UV CD spectroscopy is used to reveal changes in the secondary structure of proteins. The CD spectrum (190 - 260 nm) of cytochrome C (Cyt C) shows two minima at 208 nm and 222 nm, indicating an α-helical structure, as shown in the attached Figure 18 specification. The presence of these two peaks reflects the transition of peptide bonds in the α-helical structure. Figure 18 As shown, in the absence and presence of a certain concentration of polymerizable imidazolium-based ionic liquid monomers (ILs) (the molar concentration ratio of Cyt C / ILs is below 1:50), the α-helical structure of cytochrome C changes little. Therefore, the binding to Cyt C does not cause significant changes in the secondary structure of Cyt C, maintaining the native conformation of the protein at the secondary structure level. Thus, the CD technique reveals information on changes in the secondary structure of proteins after interaction with ligands.

[0043] The CD spectral results were analyzed by the CDNN program, and the results are shown in Table 2-11. When the molar ratio of Cyt C to the functional monomer is less than 1:50, the peak shape of the CD spectrum of Cyt C remains intact and the peak intensity changes little, with a small loss in the content of the α-helix structure. However, when the molar ratio exceeds 1:50, the CD spectrum of Cyt C fluctuates greatly, the peak shape at the characteristic absorption peak is completely destroyed, the peak intensity changes significantly, and there is a huge loss in the content of the α-helix structure.

[0044] Table 2 Content of the secondary structure of the protein with the interaction between ligand a and Cyt C ;

[0045] Table 3 Content of the secondary structure of the protein with the interaction between ligand b and Cyt C ;

[0046] Table 4 Content of the secondary structure of the protein with the interaction between ligand c and Cyt C ;

[0047] Table 5 Content of the secondary structure of the protein with the interaction between ligand d and Cyt C ;

[0048] Table 6 Content of the secondary structure of the protein with the interaction between ligand e and Cyt C ;

[0049] Table 7 Content of the secondary structure of the protein with the interaction between ligand f and Cyt C ;

[0050] Table 8 Contents of Protein Secondary Structure of the Interaction between Ligand g and Cyt C ;

[0051] Table 9 Contents of Protein Secondary Structure of the Interaction between Ligand h and Cyt C ;

[0052] Table 10 Contents of Protein Secondary Structure of the Interaction between Ligand i and Cyt C ;

[0053] Table 11 Contents of Protein Secondary Structure of the Interaction between Ligand j and Cyt C ;

[0054] Table 12 Contents of Protein Secondary Structure of the Interaction between Ligand k and Cyt C ;

[0055] Example 14 Synchronous fluorescence spectroscopy is considered a potential method for analyzing conformational changes in proteins upon binding to ligands. This method provides key information for exploring changes in the microenvironment near Trp and Tyr residues. This method offers some favorable features such as sensitivity, signal simplification, reduced signal bandwidth, and less adverse perturbation effects. The effects of 11 different concentrations of ionic liquids on the synchronous fluorescence spectrum of cytochrome c are shown in the appended Figure 19 . The synchronous spectrum is characteristic of the fluorescence of Tyr residues at detaλ = 15 nm ( Figure 19 left panel of a-k in Figure 19 ), and is typical of the fluorescence of Trp residues at detaλ = 60 nm ( Figure 19 right panel of a-k in ). The results show that the fluorescence intensity of Cyt C increases with the increase in the concentration of the ionic liquid. Figure 19 In f of

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements do not enable the modified technical solutions to depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A preparation method of a polymerizable imidazolium-based ionic liquid monomer, characterized in that, An alkylation substitution reaction is adopted, that is, a polymerizable imidazolium ionic liquid monomer is prepared by reacting N-vinylimidazole with a monomer; the preparation process of the polymerizable imidazolium ionic liquid monomer is as follows: ； Wherein, X is a monomer.

2. The preparation method of a polymerizable imidazolium-based ionic liquid monomer according to claim 1, characterized in that The monomer is any one of ethyl bromide, n-butyl bromide, decyl bromide, ethyl chloroacetate, methyl chloroacetate, benzyl chloride, vinylbenzyl chloride, chloroethyl methyl ether, chloroacetamide, β-cyclodextrin, and 3-chloropropanesulfonic acid.

3. The preparation method of a polymerizable imidazolium ionic liquid monomer according to claim 2, characterized in that The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with ethyl bromide is 1-vinyl-3-ethylimidazolium bromide ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with n-butyl bromide is 1-vinyl-3-n-butylimidazolium bromide ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with decyl bromide is 1-vinyl-3-n-decylimidazolium bromide ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with ethyl chloroacetate is 1-vinyl-3-ethyl acetate imidazolium chloride ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with methyl chloroacetate is 1-vinyl-3-methyl acetate imidazolium chloride ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with benzyl chloride is 1-vinyl-3-benzylimidazolium chloride ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with vinylbenzyl chloride is 1-vinyl-3-styrylimidazolium chloride ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with chloroethyl methyl ether is 1-vinyl-3-ethyl methyl ether imidazolium chloride ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with chloroacetamide is 1-vinyl-3-acetamide imidazolium chloride ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with β-cyclodextrin is toluenesulfonic acid 1-vinyl-β-cyclodextrin imidazolium ionic liquid monomer; The polymerizable imidazolium ionic liquid monomer prepared by reacting N-vinylimidazole with 3-chloropropanesulfonic acid is 1-vinyl-3-propane sulfonic acid imidazolium chloride ionic liquid monomer.

4. The preparation method of a polymerizable imidazolium-based ionic liquid monomer according to claim 3, characterized in that, When the monomer is any one of ethyl bromide, n-butyl bromide, and decyl bromide, the preparation includes the following steps: after mixing N-vinylimidazole and the monomer, heat it to 70 °C and reflux, then wash and dry it with a detergent. The molar ratio of N-vinylimidazole to the monomer is 1:(1 - 3.2), the detergent is ethyl acetate, the reflux time is 24 h, and the drying temperature is 60 - 70 °C.

5. The preparation method of a polymerizable imidazolium-based ionic liquid monomer according to claim 3, characterized in that, When the monomer is any one of ethyl chloroacetate, methyl chloroacetate, benzyl chloride, vinylbenzyl chloride, chloroethyl methyl ether, and chloroacetamide, the preparation includes the following steps: Mix N-vinylimidazole with the monomer in a solvent, extract with an extractant, and then freeze-dry. The molar ratio of N-vinylimidazole to the monomer is 1:(0.70 - 1.2). The solvent is a mixed solution of ethyl acetate and water or a mixed solution of ethanol and water, and the dissolution reaction time is 24 h.

6. The preparation method of a polymerizable imidazolium-based ionic liquid monomer according to claim 3, characterized in that, When the monomer is β-cyclodextrin, the preparation method of the cyclodextrin imidazolium ionic liquid monomer is as follows: S1. Dissolve β-cyclodextrin in deionized water, dropwise add an aqueous sodium hydroxide solution and an acetonitrile solution of tosyl chloride thereto, stir at 23 °C and 800 rpm for 2 hours, filter off the precipitate, refrigerate the filtrate overnight at 4 °C, and recover the precipitated tosylated-β-cyclodextrin by filtration; the mass-volume ratio of β-cyclodextrin:deionized water:sodium hydroxide:water:tosyl chloride:acetonitrile is 6 g:0.05 L:0.66 g:0.002 L:1 g:0.003 L; S2. Dissolve tosylated-β-cyclodextrin in a mixed solution of 1-vinylimidazole and N,N-dimethylformamide, react at 75 °C for 4 h under a N2 atmosphere; after cooling to ambient temperature, precipitate the crude product by using acetone, then filter, and dry overnight in a vacuum oven at 50 °C to obtain tosylated 1-vinyl-β-cyclodextrin imidazolium ionic liquid; the mass-volume ratio of tosylated-β-cyclodextrin:1-vinylimidazole:N,N-dimethylformamide:acetone is 6.45 g:0.002 L:0.015 L:0.07 L.

7. A polymerizable imidazolium-based ionic liquid monomer, characterized in that, The polymerizable imidazolium ionic liquid monomer is prepared by the preparation method of the polymerizable imidazolium ionic liquid monomer according to any one of claims 1 - 6.

8. A screening method for polymerizable imidazolium-based ionic liquid monomers according to claim 7, characterized in that, Including the following steps: (1) Study on the interaction energy between protein and imidazolium ionic liquid monomer Calculate the interaction energy between the polymerizable imidazolium ionic liquid monomer and the template molecule of the protein in the aqueous phase; First, use GaussView05 software to construct the geometric configurations of the template molecule and the polymerizable imidazolium ionic liquid monomer, and use Autodock software to perform molecular docking on the polypeptide of the optimized template molecule and the polymerizable imidazolium ionic liquid monomer. The docking runs 10 times to achieve the docking between the template molecule and the ligand of the polymerizable imidazolium ionic liquid monomer; Secondly, with the help of the Gaussian16 program, use the DFT algorithm, B3LYP / 6-31G basis set, and DFT-D3 dispersion correction to optimize the configurations of the polypeptide of the template molecule and the polymerizable imidazolium ionic liquid monomer, and calculate the binding free energy between the polymerizable imidazolium ionic liquid monomer and the protein; (2) Study on the effect of imidazolium ionic liquid monomer on the secondary structure of protein Prepare a template protein solution with a concentration of 0.05 mg / mL. Prepare imidazolium ionic liquid monomer solutions respectively. Pipette 3.00 mL of the protein solution into a series of test tubes. According to different molar ratios of the template molecule to the imidazolium ionic liquid monomer, add imidazolium ionic liquid monomer solutions with the same volume as the protein. The molar ratios of the template protein to the ionic liquid monomer are 1:0, 1:5, 1:10, 1:15, 1:20, 1:25, 1:50, 1:75, 1:100 respectively. After incubating the prepared protein-ionic liquid monomer mixed solution at 4 °C for 24 h, perform circular dichroism spectroscopy tests; all spectroscopy tests are carried out at 25 °C, using a 1 cm quartz cuvette for measurement, set the wavelength to 190 - 250 nm, the scanning speed to 20 nm / min, the resolution to 0.60 nm, and the background value needs to be subtracted before measuring the sample; (3)Study on the effect of imidazolium ionic liquid monomer on the tertiary structure of proteins Prepare a template protein solution with a concentration of 0.05 mg / mL. Prepare imidazolium ionic liquid monomer solutions respectively. Pipette 3.00 mL of the protein solution into a series of test tubes. According to different molar ratios of the template molecule to the imidazolium ionic liquid monomer, add imidazolium ionic liquid monomer solutions with the same volume as the protein. The molar concentration ratios of the template protein to the ionic liquid monomer are 1:0, 1:5, 1:10, 1:15, 1:20, 1:25, 1:50, 1:75, 1:100 respectively. After incubating the prepared protein-ionic liquid monomer mixed solution at room temperature for 24 h, perform fluorescence spectroscopy tests; all spectroscopy tests are carried out at 25 °C, using a 1 cm quartz cuvette for measurement, set the wavelength to 260 - 380 nm, and the background value needs to be subtracted before measuring the sample.

9. A screening method for a polymerizable imidazolium-based ionic liquid monomer according to claim 8, characterized in that In step (1), the calculation formula for the binding free energy between the imidazolium ionic liquid monomer and the template protein is: ； In the formula, E 蛋白-咪唑基离子液体单体 is the potential energy of the template molecule-functional monomer complex in water; E 蛋白 is the potential energy of the template molecule in water; E 咪唑基离子液体单体 is the potential energy of the imidazolium-based ionic liquid monomer in water.

10. A screening method for a polymerizable imidazolium-based ionic liquid monomer according to claim 8, characterized in that, The protein template molecule described above is applicable to all proteins, including but not limited to cytochrome C, bovine serum albumin, human serum albumin, and ovalbumin.

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