阅读说明：本技术 一种适于复杂水样分析的分子印迹聚合物微球的制备方法 (Preparation method of molecularly imprinted polymer microspheres suitable for complex water sample analysis ) 是由 张会旗 马玉娟 郑从光 于 2019-02-18 设计创作，主要内容包括：本发明涉及一种制备适于复杂水样分析的分子印迹聚合物微球的新方法。所述表面具有亲水性高分子刷的分子印迹聚合物微球是通过表面具有环氧基团的分子印迹聚合物微球与亲水性大分巯醇在催化剂作用下进行化学偶联反应制得的。本发明具有合成方法简单、适用范围广、产品结构明确等优点。所得表面具有亲水性高分子刷的分子印迹聚合物微球在食品安全、环境监测、生物医用等众多领域具有广阔的应用前景。(The invention relates to a novel method for preparing molecularly imprinted polymer microspheres suitable for complex water sample analysis. The molecularly imprinted polymer microsphere with the hydrophilic polymer brush on the surface is prepared by carrying out chemical coupling reaction on the molecularly imprinted polymer microsphere with the epoxy group on the surface and hydrophilic macromolecular mercaptol under the action of a catalyst. The invention has the advantages of simple synthesis method, wide application range, definite product structure and the like. The obtained molecularly imprinted polymer microspheres with the hydrophilic polymer brushes on the surfaces have wide application prospects in various fields of food safety, environmental monitoring, biomedicine and the like.)

1. A method for preparing Molecularly Imprinted Polymer (MIPs) microspheres suitable for complex water sample analysis is characterized in that hydrophilic macromolecule brushes are arranged on the surfaces of the MIPs microspheres, and the MIPs microspheres are prepared by chemical coupling reaction of hydrophilic macromolecule mercaptol and MIPs microspheres with epoxy groups on the surfaces under the action of a catalyst.

2. The method for preparing MIPs microspheres for complex water sample analysis according to claim 1, characterized by comprising the steps of:

1) uniformly mixing hydrophilic macromolecular mercaptol, MIPs microspheres with epoxy groups on the surfaces, a catalyst and a solvent, removing oxygen in the system, and sealing;

2) and (3) carrying out coupling reaction on the reaction system at a certain temperature for a proper time to obtain the MIPs microspheres with hydrophilic polymer brushes on the surfaces and suitable for complex water sample analysis.

3. The method for preparing MIPs microspheres for complicated water sample analysis according to claims 1 and 2, wherein the hydrophilic macromolecular thiol is various hydrophilic polymers having thiol end groups.

4. The method for preparing MIPs microspheres for complicated water sample analysis according to claims 1 and 2, wherein the MIPs microspheres having epoxy groups on the surface are prepared directly by various precipitation polymerization methods or by introducing epoxy groups through chemical modification of the surface of MIPs microspheres.

5. The method for preparing MIPs microspheres for complicated water sample analysis according to claims 1 and 2, wherein the MIPs microspheres having epoxy groups on the surface have a surface epoxy group content of 0.001 to 1.0 mmol/g.

6. The method for preparing MIPs microspheres for complicated water sample analysis according to claims 1 and 2, wherein the catalyst is organic base such as triethylamine, tetrabutylammonium fluoride, inorganic base such as lithium hydroxide, organic acid such as acetic acid, or inorganic acid such as boron trifluoride.

7. The method for preparing MIPs microspheres suitable for complicated water sample analysis according to claim 2, wherein the solvent used for the coupling reaction is an amide-based solvent such as N, N-dimethylformamide, N-dimethylacetamide, hexamethylphosphoric triamide, sulfone and sulfoxide-based solvents such as dimethyl sulfoxide, dimethyl sulfone, sulfolane, ether-based solvents such as tetrahydrofuran, 1, 4-dioxane, N-butyl ether, ketone-based solvents such as acetone, butanone, heptanone, alcohol-based solvents such as methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, nitrile-based solvents such as acetonitrile, halogenated alkane solvents such as dichloromethane, trichloromethane, carbon tetrachloride, other common solvents such as N-methylpyrrolidone, water, or a mixture of two or more of the above solvents.

8. The method for preparing MIPs microspheres for complicated water sample analysis according to claim 2, wherein the MIPs microspheres having epoxy groups on the surface, the hydrophilic macromolecular thiol, the catalyst, and the solvent are used in the following amounts:

1) the dosage of the MIPs microspheres with epoxy groups on the surfaces and the hydrophilic macromolecular mercaptol is calculated according to the molar ratio of the epoxy groups on the surfaces of the MIPs microspheres to the mercapto groups of the hydrophilic macromolecular mercaptol of 1: 0.1-100;

2) the molar ratio of the catalyst to the hydrophilic macromolecular mercaptoalcohol is 0.1-200: 1;

3) the dosage ratio of the solvent to the MIPs microspheres with epoxy groups on the surface is 0.04-2L/g.

9. The method for preparing MIPs microspheres for complex water sample analysis as claimed in claim 2, wherein the temperature of the coupling reaction is 25-100 ℃ and the reaction time is 1-500 hours.

Technical Field

The invention relates to a preparation method of a molecularly imprinted polymer microsphere suitable for complex water sample analysis, in particular to a novel method for modifying the surface of the molecularly imprinted polymer microsphere by using a thiol-epoxy coupling reaction, and the molecularly imprinted polymer microsphere which has a hydrophilic polymer brush on the surface and is suitable for complex water sample analysis can be obtained by the method.

Background

Molecularly Imprinted Polymers (MIPs) are functional polymers having specific recognition sites. The compound has the advantages of high stability, easy preparation and low cost, and also has high affinity and selectivity which are comparable with those of natural biological receptors, so that the compound has great application prospects in various fields such as solid-phase extraction, chromatographic separation, immunoassay, sensors, enzyme-like catalysis, organic synthesis, drug delivery, biological drugs and the like, and becomes a hotspot for research in the field of molecular recognition at present (Zhang, H.; Ye, L.; Mosbach, K.J.mol.Recognit.2006, 19, 248-259).

Although molecular imprinting research has been greatly advanced and MIPs have entered into commercial applications in some application fields (e.g., solid phase extraction), most MIPs currently available show excellent molecular recognition performance for small organic molecules only in organic solutions, and their selective recognition performance for small organic molecules disappears once they are applied to aqueous systems. This is mainly due to their high surface hydrophobicity which leads to their high non-specific adsorption of small organic molecules in aqueous solution (Dirion, B.; Cobb, Z.; Schillinger, E.; Andersson, L.I.; Sellergren B.J.Am. chem. Soc.2003, 125, 15101-. The practical application of MIPs in the fields of bioanalysis and biomedical based on aqueous solution systems is greatly hindered by the above problems.

In recent years, some MIPs microspheres (Zhang, h.polymer 2014, 55, 699-. For example, MIPs (DeFaria, H.D.; de Carvalho) having the ability to selectively recognize small organic molecules in a simple water sample are finally obtained by a method of first preparing MIPs having epoxy groups on the surface and then converting the epoxy groups on the surface into hydrophilic hydroxyl groups through a ring-opening reactionL.C.; santos, m.g.; barbosa a.f.; figueiredo, e.c. anal.chim.acta 2017, 959, 43-65). However, the selective recognition capability of the compounds on organic small molecules in complex water samples (such as biological samples of milk, serum and the like) is completely lost through experiments. In view of the easy preparation of MIPs with epoxy groups on the surface (by adding in an imprinted polymerization system)Epoxy-containing polymerizable monomers are added or the surface of the MIPs is modified to introduce surface epoxy groups), so that how to develop a new method capable of converting the epoxy-containing polymerizable monomers into the MIPs suitable for complex water sample analysis has important practical significance and application value.

Recently, we successfully realized the one-step preparation of the "active" MIPs microspheres (Zhang, h.eur.polym.j.2013, 49, 579-; further, the method of "Grafting from" (i.e. CRP of hydrophilic monomers surface-initiated on "active" MIPs microspheres) (Zhao, M.; Zhang, C.; Zhang, Y.; Guo, X.; Yah, H.; Zhang, H.chem.Commun.2014, 50, 2208-. However, how to prepare MIPs suitable for complex water samples by effectively grafting hydrophilic polymer brushes on MIPs microspheres with epoxy groups on the surfaces has not been reported.

Disclosure of Invention

In order to solve the problems, the invention provides a novel MIPs microsphere surface modification method, and aims to convert MIPs microspheres with epoxy groups on the surface, which are not suitable for complicated water sample analysis, into MIPs suitable for complicated water sample analysis by developing a simple and efficient novel method for grafting hydrophilic polymer brushes on the surfaces of the MIPs microspheres with epoxy groups on the surfaces. The invention has the advantages of simple synthesis method, wide application range, definite product structure and the like.

The technical scheme is as follows:

the invention develops a simple and easy method for preparing MIPs microspheres with hydrophilic polymer brushes on the surfaces and suitable for complex water sample analysis by utilizing a thiol-epoxy coupling reaction.

The specific technical scheme for preparing the MIPs microspheres with the hydrophilic polymer brushes on the surfaces is as follows:

1) feeding MIPs microspheres with epoxy groups on the surfaces and hydrophilic macromolecular mercaptoalcohol according to the mol ratio of the epoxy groups on the surfaces of the MIPs microspheres to the hydrophilic macromolecular mercaptoalcohol of 1: 0.1-100;

2) feeding a catalyst according to the molar ratio of the catalyst to the hydrophilic macromolecular mercaptol of 0.1-200: 1;

3) feeding a solvent according to the proportion of the solvent to MIPs microspheres with epoxy groups on the surface of the MIPs microspheres being 0.04-2L/g;

4) mixing the above materials, removing oxygen in the system, and sealing;

5) and (3) reacting the sealed reaction system at the temperature of 25-100 ℃ for 1-500 hours to obtain the MIPs microspheres with the hydrophilic polymer brushes on the surfaces.

The MIPs microspheres with epoxy groups on the surfaces are directly prepared by various precipitation polymerization methods or prepared by introducing the epoxy groups through chemical modification on the surfaces of the MIPs microspheres, and the content of the epoxy groups on the surfaces of the MIPs microspheres is 0.001-1.0 mmol/g.

The hydrophilic macromolecule thiol is various hydrophilic polymers with thiol end groups.

The catalyst is an organic base such as triethylamine, tetrabutylammonium fluoride, an inorganic base such as lithium hydroxide, an organic acid such as acetic acid, or an inorganic acid such as boron trifluoride.

The solvent is an amide solvent such as N, N-dimethylformamide, N-dimethylacetamide, hexamethylphosphoric triamide, sulfone and sulfoxide solvents such as dimethyl sulfoxide, dimethyl sulfone, sulfolane, ether solvents such as tetrahydrofuran, 1, 4-dioxane, N-butyl ether, ketone solvents such as acetone, butanone, heptanone, alcohol solvents such as methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, nitrile solvents such as acetonitrile, halogenated alkane solvents such as dichloromethane, trichloromethane, carbon tetrachloride, other common solvents such as N-methylpyrrolidone, water, or a mixture of two or more of the above solvents.

Description of the drawings:

FIG. 1 is a flow chart of a process for grafting hydrophilic polymer brushes onto MIPs microspheres using a thiol-epoxy chemical coupling method.

FIG. 2 is a scanning electron micrograph of MIPs microspheres (Propranolol-MIP-EP) with epoxy groups on the surface.

FIG. 3 is a scanning electron microscope photograph of MIPs microspheres (using Propranolol as a template) with epoxy groups on the surface corresponding to non-imprinted polymer microspheres (Propranolol-CP-EP).

FIG. 4 shows a poly (hydroxyethyl methacrylate) brush (M) with hydrophilic surface obtained by thiol-epoxy chemical coupling method_n5740g/mol) of MIPs microspheres (Propranolol-MIP-PHEMA-5740).

FIG. 5 shows a poly (hydroxyethyl methacrylate) brush (M) with hydrophilic surface obtained by thiol-epoxy chemical coupling method_n5740g/mol) of MIPs microspheres (Propranolol-CP-PHEMA-5740) of non-imprinted polymer microspheres (Propranolol-CP-PHEMA-5740).

FIG. 6 shows a brush with hydrophilic poly (hydroxyethyl methacrylate) polymer on the surface (M)_n5740g/mol) MIPs microspheres (Propranolol as template molecule) (Propranolol-MIP-PHEMA-5740) and non-imprinted polymer microspheres (Propranolol-CP-PHEMA-5740) have equilibrium adsorption performance on Propranolol in pure milk (adsorption temperature 25 ℃, concentration of Propranolol 0.1 mM).

FIG. 7 shows a brush with hydrophilic poly (hydroxyethyl methacrylate) polymer on the surface (M)_n5740g/mol) of MIPs microspheres (Propranolol-MIP-PHEMA-5740) and non-imprinted polymer microspheres (Propranolol-CP-PHEMA-5740) in pure milk for selective adsorption of Propranolol and its analogs to PropranololCan (the adsorption temperature is 25 ℃, the concentrations of Propranolol and Propranolol are both 0.1mM, and the concentrations of Propranolol-MIP-PHEMA-5740 and Propranolol-CP-PHEMA-5740 are both 0.6 mg/mL).

Detailed Description

Example 1

150 mg of MIPs microspheres with epoxy groups on the surface using propranolol as a template are added into a round-bottom flask containing 30 ml of methanol, and then 188 mg of polyhydroxyethyl methacrylate (M) containing thiol end groups are added_n5740g/mol) and 780 μ l triethylamine. Introducing argon into the reaction mixture for 30 minutes to remove oxygen, sealing the reaction system, placing the reaction system in a constant-temperature oil bath at 25 ℃, reacting for 72 hours under electromagnetic stirring, centrifuging the reaction product, washing the reaction product three times with methanol, and drying the reaction product in vacuum at 40 ℃ to constant weight to obtain the polyhydroxyethyl methacrylate polymer brush (M) with the hydrophilic surface_n5740g/mol) MIPs microspheres (Propranolol-MIP-PHEMA-5740).

Surface hydrophilic polyhydroxyethyl methacrylate (M)_n5740g/mol) brush non-imprinted polymer microspheres (properanol-CP-PHEMA-5740) were prepared as above except that MIPs microspheres having epoxy groups on the surface were replaced with non-imprinted polymer microspheres having epoxy groups on the surface.

Example 2

150 mg of MIPs microspheres having epoxy groups on the surface and using propranolol as a template were added to a round-bottom flask containing 30 ml of methanol, and then 90 mg of polyhydroxyethyl methacrylate (M) having thiol end groups was added_n2500g/mol) and 350 microliters triethylamine. Introducing argon into the reaction mixture for 30 minutes to remove oxygen, sealing the reaction system, placing the reaction system in a constant-temperature oil bath at 25 ℃, reacting for 72 hours under electromagnetic stirring, centrifuging the reaction product, washing the reaction product three times with methanol, and drying the reaction product in vacuum at 40 ℃ to constant weight to obtain the polyhydroxyethyl methacrylate polymer brush (M) with the hydrophilic surface_n2500g/mol) MIPs microspheres (propranol-MIP-PHEMA-2500).

Surface hydrophilic polyhydroxyethyl methacrylate (M)_n2500g/mol) of non-imprinted polymer microspheres (Propranol-CP-PHEMA-2500) prepared by the same procedure asIn the above, the MIPs microspheres having epoxy groups on the surface are replaced by the non-imprinted polymer microspheres having epoxy groups on the surface.

Example 3

150 mg of MIPs microspheres having epoxy groups on the surface and using 2, 4-dichlorophenoxyacetic acid (2, 4-D) as a template were put into a round-bottomed flask containing 30 ml of methanol, and 188 mg of polyhydroxyethyl methacrylate (M) having thiol end groups was added_n5740g/mol) and 780 μ l triethylamine. Introducing argon into the reaction mixture for 30 minutes to remove oxygen, sealing the reaction system, placing the reaction system in a constant-temperature oil bath at 25 ℃, reacting for 72 hours under electromagnetic stirring, centrifuging the reaction product, washing the reaction product three times with methanol, and drying the reaction product in vacuum at 40 ℃ to constant weight to obtain the polyhydroxyethyl methacrylate polymer brush (M) with the hydrophilic surface_n5740g/mol) MIPs microspheres (2, 4-D-MIP-PHEMA-5740).

Surface grafting of hydrophilic polyhydroxyethyl methacrylate (M)_n5740g/mol) of non-imprinted polymer microspheres (2, 4-D-CP-PHEMA-5740) was prepared as above except that the MIPs microspheres having epoxy groups on the surface were replaced with non-imprinted polymer microspheres having epoxy groups on the surface.

Example 4

150 mg of MIPs microspheres with epoxy groups on the surface and 2, 4-D as a template are added into a round-bottom flask containing 30 ml of methanol, and then 90 mg of polyhydroxyethyl methacrylate (M) with thiol end groups is added_n2500g/mol) and 350 microliters triethylamine. Introducing argon into the reaction mixture for 30 minutes to remove oxygen, sealing the reaction system, placing the reaction system in a constant-temperature oil bath at 25 ℃, reacting for 72 hours under electromagnetic stirring, centrifuging the reaction product, washing the reaction product three times with methanol, and drying the reaction product in vacuum at 40 ℃ to constant weight to obtain the polyhydroxyethyl methacrylate polymer brush (M) with the hydrophilic surface_n2500g/mol) MIPs microspheres (2, 4-D-MIP-PHEMA-2500).

Surface grafting of hydrophilic polyhydroxyethyl methacrylate (M)_n2500g/mol) of non-imprinted polymer microspheres (2, 4-D-CP-PHEMA-2500) was prepared as above except that the MIPs microspheres having epoxy groups on the surface were replaced with non-imprinted polymer microspheres having epoxy groups on the surface.