CN105153331A - Method and product for preparing autofluorescence polystyrene materials - Google Patents

Abstract

The invention provides a method and product for preparing autofluorescence polystyrene material, which is characterized in that on the surface of polystyrene material, especially on the surface of polystyrene microspheres, it is acylated by Friedel-Crafts under the action of an acidic catalyst The (alkylation) reaction introduces a small molecule color-producing (color-aiding) functional group, which forms a π-π (p-π) conjugation with the large π bond of the benzene ring to form a conjugated system, which undergoes electronic transition under the action of excitation light Produce fluorescence. Under the excitation of 405nm laser, the prepared polystyrene fluorescent microspheres can produce obvious fluorescent signals in the blue, green and orange channels of the laser confocal microscope. At the same time, we found that the introduction of electron-withdrawing groups on the conjugated substituents can red-shift the emission peak of polystyrene materials. The preparation method of the invention is simple, high in efficiency and low in cost. The prepared autofluorescent polystyrene microspheres have the characteristics of high fluorescence intensity, stable chemical properties, no fluorescence leakage, high mechanical strength, etc., and have great application potential in the fields of biomedicine and electronic light-emitting devices.

Description

A method and product for preparing autofluorescent polystyrene material

technical field

The invention relates to a method and product for preparing autofluorescent polystyrene materials, especially to functionalize the surface of polystyrene microspheres, and the obtained microspheres can emit fluorescence under the excitation of ultraviolet light, and are used in biomedicine and light-emitting devices. and other fields have great application potential, and belong to the field of preparation of functional polymer materials.

Background technique

Organic fluorescent polymer materials are research hotspots in the field of materials science in recent years (Anal. Lett., 2000, 33, 3183-3197; Macromol. Chem. Phys., 2002, 203, 1833-1843), and have been used in various technical fields Especially in the field of biomedical detection, it has been widely used. Compared with fluorescent small molecules, fluorescent polymer materials have the advantages of uniform distribution of chromophores, stable content, and good luminescence performance. There are three main application methods of organic fluorescent polymer materials: 1) fluorescent polymer microspheres; 2) fluorescent polymer films; 3) fluorescent polymer sheets.

Polymer fluorescent microspheres have great application potential in labeling, tracing, detection, immobilized enzymes, and high-throughput drug screening due to their stable morphological structure and luminous efficiency (Polymer Materials Science and Engineering, 2004, 20 (4):42-45). The preparation methods of polymer fluorescent microspheres mainly include adsorption method, embedding method, chemical coupling method, swelling method, copolymerization method and so on. The preparation method of the adsorption method is simple, but the dye on the surface of the fluorescent microsphere is easy to fall off; the embedding method is to disperse the dye evenly in the monomer, and prepare it by polymerization reaction or layer-by-layer self-assembly. The obtained microspheres generally have a core-shell structure. The fluorescent properties of the obtained microspheres are stable, but there is a problem of dye leakage; the chemical coupling method is to bond the dye molecules to the surface of the microspheres through chemical reactions, which is easily limited by the number of binding sites on the surface of the microspheres, and the fluorescent dye molecules are easily affected by Environmental interference; the copolymerization method refers to fluorescent microspheres prepared by polymerizing fluorescent substances with polymerizable functional groups and organic monomers, and the fluorescent groups are evenly distributed and difficult to leak (Adv.Mater.,2012,24:637-641) , but the problem of the copolymerization method is that it is easy to produce chain transfer reaction and it is difficult to obtain high molecular weight polymers. By introducing small molecular functional groups on the microspheres, under the conjugation induction, the π-π* and n-π* of the unsaturated bonds in the system produce electronic transitions and autofluorescence (Adv.Funct.Mater.,2007,17: 3153-3158), the fluorescent polymer microspheres obtained by this method have stable fluorescent properties, are not prone to photobleaching, can overcome the shortcomings of the above-mentioned preparation methods, and have great development potential.

The matrix of polymer fluorescent microspheres includes natural and synthetic polymer materials, such as chitosan, agarose, polystyrenes, poly(meth)acrylates, polyacrylamides, etc., wherein polystyrene materials Due to the advantages of high mechanical strength, good chemical stability, and uniform particle size, it has great application potential in the field of biomedicine, especially the technology of fluorescently encoded microspheres. The invention provides an effective method and product for preparing autofluorescent polymer materials. During the research, we found that polystyrene microspheres have autofluorescence after Friedel-Crafts reaction. By adjusting the types of functional groups, the fluorescence intensity and quantum yield of microspheres The rate can be adjusted within a certain range. The functional group can be used to further graft hydrophilic polymers to obtain hydrophilic polystyrene fluorescent microspheres. The method and product provided by the invention have great application potential in the fields of biomedicine, electronic light-emitting devices and the like.

Contents of the invention

The present invention utilizes the Friedel-Crafts acyl (alkyl) reaction, and the purpose is to produce a π-π (p-π) conjugation with a large π bond of a benzene ring to form a conjugated system in polystyrene color-generating (color-aiding) functional groups, Under the action of excitation light, fluorescence is generated through electronic transition. At the same time, the introduced functional groups can be used to further graft hydrophilic polymers to obtain autofluorescent hydrophilic polystyrene materials. The polystyrene fluorescent microspheres prepared by the invention have the advantages of high mechanical strength, stable chemical properties, high fluorescence intensity, good stability, no fluorescence leakage phenomenon, etc., and have great application potential in the fields of biomedicine and electronics.

The invention provides a method and product for preparing autofluorescence polystyrene material, the method is as follows:

Step 1. Reference method (ion exchange and adsorption, 2005, 21 (4): 289 ~ 296; Journal of Chengdu University of Science and Technology, 1993, 76 (6): 44 ~ 50) under the action of an acidic catalyst, using the Friedel-Crafts reaction Acylate or alkylate the benzene ring of polystyrene to obtain substance A with the following general formula:

Where R can be O=C(CH ₂ ) _n (n=1-18), (CH ₂ ) _n (n=1-4), (CH ₃ ) ₂ CC=O, O ₂ SC ₆ H ₄ , X is H, Cl or Br. The functional group of A is that RX is haloalkyl, haloalkylacyl, alkylacyl, benzenesulfonyl or halobenzenesulfonyl.

Step 2. For cross-linked polystyrene microspheres or cross-linked polystyrene plates, first use a microporous filter membrane to suction filter the reaction solution in anhydrous state, and pour the separated solid matter into glacial hydrochloric acid to stir quickly, and then Filter and wash with deionized water until neutral, and finally wash and filter with absolute ethanol, and dry in a vacuum oven to obtain the autofluorescent product.

For linear polystyrene, since it is dissolved in the reaction solvent, ethanol or methanol needs to be added after the reaction to precipitate the reaction product and then suction filtered. The subsequent steps are the same as cross-linked polystyrene microspheres or polystyrene plates.

The polystyrene material in the present invention can be linear polystyrene or cross-linked polystyrene, preferably cross-linked polystyrene microspheres or polystyrene plates.

Preferably, the particle size of the crosslinked polystyrene microspheres in step 1 of the present invention is in the range of 0.05-1000 μm.

The organic solvent described in step 1 is ethers, halogenated alkanes, benzene homologues, ethyl acetate, etc., preferably one of dichloromethane, dichloroethane, nitrobenzene or carbon disulfide.

Preferably, the acylating agent described in step 1 is acetyl chloride, acetyl bromide, propionyl chloride, propionyl bromide, butyryl chloride, butyryl bromide, isobutyryl chloride, isobutyryl bromide, chloroacetyl chloride, bromoacetyl bromide, chlorine Any of propionyl chloride, bromopropionyl bromide, chlorobutyryl chloride, bromobutyryl bromide, benzenesulfonyl chloride, benzenesulfonyl bromide, chlorobenzenesulfonyl chloride, bromobenzenesulfonyl chloride, the alkylating agent is chloromethyl methyl ether , Chloromethyl ether, bromomethyl methyl ether, bromomethyl ether, chloroethyl methyl ether, chloroethyl ether, bromoethyl methyl ether, bromoethyl ether, any one. Preferably, the acidic catalyst described in step 1 is any one of anhydrous aluminum trichloride, anhydrous ferric chloride, anhydrous zinc chloride, anhydrous antimony trichloride and anhydrous tin chloride.

The molar ratio of the acylating agent (alkylating agent) to the reactive benzene ring on the polystyrene microsphere is 0.5-10, preferably 1-3; the ratio of the solvent volume to the PS microsphere mass (ml/g ) is 5-100, preferably 10-20; the reaction temperature is 0-100°C, preferably 30-60°C; the reaction time is 1-24h, preferably 3-6h.

The technical effect that the present invention produces:

The invention provides a simple method and product for preparing autofluorescence polystyrene material. Polystyrene material can be purchased or made by yourself. By choosing different Friedel-Crafts reagents, polystyrene products with different fluorescence intensities can be obtained. In particular, the prepared autofluorescent polystyrene microspheres have the characteristics of stable fluorescence properties, high fluorescence intensity, and no fluorescence leakage phenomenon because the autofluorescence properties of the microspheres are produced by their own conjugated structures. Moreover, the preparation method has simple operation and good repeatability. The autofluorescent polystyrene microspheres prepared by the invention have great potential in the fields of biomedicine, immune analysis, drug tracing, electronic light-emitting devices and the like.

Description of drawings

Fig. 1 is the infrared spectrogram before and after reaction of polystyrene microsphere and chloroacetyl chloride in embodiment 2,

Among them, a line is the infrared spectrum of polystyrene microspheres,

Line b is the infrared spectrum after the reaction of polystyrene microspheres with chloroacetyl chloride;

Fig. 2 is the fluorescence emission spectrum of the autofluorescence polystyrene material prepared in each embodiment of the present invention under the excitation wavelength of 395nm,

Among them, line a is the fluorescence emission spectrum of PS-BSC microspheres,

Line b is the fluorescence emission spectrum of PS-AC microspheres,

Line c is the fluorescence emission spectrum of PS-BIBB microspheres,

Line d is the fluorescence emission spectrum of PS-CMME microspheres,

Line e is the fluorescence emission spectrum of PS-CAC microspheres;

Fig. 3 is the laser confocal photo of polystyrene fluorescent microspheres under 405nm excitation wavelength in embodiment 5, embodiment 6 and embodiment 7,

Wherein, graphs a, b, and c are laser confocal photos of benzenesulfonylated polystyrene fluorescent microspheres in Example 5, and PS-BSC in the blue channel, green channel, and orange channel respectively,

Figures d, e, and f are laser confocal photos of acetylated polystyrene fluorescent microspheres PS-AC in the blue channel, green channel and orange channel respectively in Example 6,

Figures g, h, and i are laser confocal photos of chloromethylated polystyrene fluorescent microspheres PS-CMME in the blue channel, green channel and orange channel in Example 7, respectively.

detailed description

The above content of the present invention will be further described in detail below through specific examples.

Example 1

Weigh 2g of linear polystyrene (PS) into a three-necked flask, add 30ml of carbon disulfide to soak and dissolve, then add 4.5g of anhydrous AlCl ₃ and 5.25g of chlorobutyryl chloride (CBC) in turn, and stir for 5 hours under reflux condensation. The reaction temperature is 40°C. After the reaction is completed, cool to room temperature and precipitate with ethanol, and then filter the sample with a microporous membrane. The filtered solid matter is quickly poured into glacial hydrochloric acid and stirred, filtered again and washed with deionized water until neutral. Finally, it was washed and filtered with absolute ethanol, and dried in a vacuum oven to obtain the autofluorescent polystyrene material PS-CBC. Finally, the prepared polystyrene fluorescent material was heated and dissolved in a tetrahydrofuran solution, and a film was spin-coated on a glass plate, and an autofluorescent polystyrene film was obtained after the solvent evaporated.

Example 2

Weigh 2 g of cross-linked polystyrene microspheres (PS) and place them in a three-necked flask, add 30 ml of dichloroethane to soak and swell, then add 4.5 g of anhydrous AlCl ₃ and 4.12 g of chloroacetyl chloride (CAC) successively, and condense under reflux Under the condition of stirring and reacting for 4 hours, the reaction temperature is 50°C. After the reaction is completed, the sample is separated by filtering with a microporous membrane. The filtered solid matter is quickly poured into glacial hydrochloric acid and stirred, filtered again and washed with deionized water until neutral, and finally used Wash and filter with absolute ethanol, and dry in a vacuum oven to prepare autofluorescent polystyrene microspheres PS-CAC.

Example 3

Weigh 2 g of cross-linked polystyrene microspheres (PS) and place them in a three-necked flask, add 30 ml of dichloromethane to soak and dissolve, then add anhydrous ZnCl ₂ 5.0 g and 2-bromoisobutyryl bromide (BIBB) 6.32 g. Stir the reaction for 5 hours under the condition of reflux condensation, and the reaction temperature is 60°C. After the reaction is completed, use a microporous membrane to filter and separate the sample. Finally, it was washed and filtered with absolute ethanol, and dried in a vacuum oven to obtain autofluorescent polystyrene microspheres PS-BIBB.

Example 4

Weigh 2 g of cross-linked polystyrene board (PS) and add 40 ml of carbon disulfide (CS ₂ ) to soak and swell, then add 4.9 g of anhydrous FeCl ₃ and 5.43 g of bromoacetyl bromide (BAB) in turn, and stir for 5 h under reflux condensation. The reaction temperature is 45°C. After the reaction is completed, filter and separate the reaction mixture. The filtered solid matter is quickly put into glacial hydrochloric acid and stirred, filtered again and washed with deionized water until neutral, and finally washed and filtered with absolute ethanol. After drying in medium, the autofluorescent polystyrene plate PS-BAB was prepared.

Example 5

Weigh 2 g of cross-linked polystyrene microspheres (PS) and add 30 ml of carbon disulfide to soak and swell, then add 4.5 g of anhydrous AlCl ₃ and 5.87 g of benzenesulfonyl chloride (BSC) successively, and stir and react for 4 h under reflux condensation conditions, and the reaction temperature is 50°C, after the reaction is completed, use a microporous membrane to filter and separate the reaction mixture. The filtered solid matter is quickly poured into glacial hydrochloric acid and stirred, filtered again and washed with deionized water until neutral, and finally washed and filtered with absolute ethanol. Dry in a vacuum oven to prepare autofluorescent polystyrene microspheres PS-BSC.

Example 6

Weigh 2 g of cross-linked polystyrene microspheres (PS) and add 30 ml of dichloroethane to soak and swell, then add anhydrous ZnCl ₂ 5.0 g and acetyl chloride (AC) 3.94 g in turn, stir and react for 5 h under reflux condensation conditions, and react The temperature is 40°C. After the reaction is completed, use a microporous membrane to filter and separate the reaction mixture. The filtered solid matter is quickly poured into glacial hydrochloric acid and stirred, filtered again and washed with deionized water until neutral, and finally washed and filtered with absolute ethanol. , and dried in a vacuum oven to prepare autofluorescent polystyrene microspheres PS-AC.

Example 7

Weigh 2 g of cross-linked polystyrene microspheres (PS) and add 30 ml of chloromethyl methyl ether (CMME) to soak and swell, then add anhydrous AlCl ₃ 4.5 g and CMME 10 ml in turn, stir and react for 10 h under reflux condensation conditions, and the reaction temperature is 40°C, after the reaction is completed, use a microporous membrane to filter and separate the reaction mixture, then wash the microspheres with methylal/acetone, deionized water, ethanol and methanol in sequence, and dry them in a vacuum oven to obtain autofluorescent polyphenylene Ethylene microspheres PS-CMME.

Experimental example:

In order to verify whether the functional conjugated groups have been coupled to the surface of polystyrene microspheres, infrared characterization was performed on the autofluorescent polystyrene microspheres prepared in Example 2. Its result is shown in accompanying drawing 1, compares with PS microsphere, the polystyrene microsphere (PS-CAC) of chloroacetylation appears two new characteristic absorption peaks at 1687cm ^-1 and 645cm ^-1 place, respectively It belongs to the stretching vibration peak of C=O and the stretching vibration peak of C-Cl connected to the benzene ring, which shows that chloroacetyl chloride has successfully reacted with PS microspheres.

In order to verify the fluorescent properties of the autofluorescent polystyrene material prepared in the present invention, fluorescence spectrum analysis was performed on the prepared fluorescent material. The results are shown in Figure 2, at the excitation wavelength of 395nm, the fluorescence intensity of different polystyrene fluorescent materials has a great difference, and all materials have a very wide fluorescence emission in the range of 430nm-550nm peak.

In order to further verify the fluorescent properties of the autofluorescent polystyrene material prepared in the present invention, we performed laser confocal microscope characterization on it. Its result is as shown in accompanying drawing 3, under the excitation of 405nm laser, the polystyrene fluorescent microsphere prepared by the present invention can all produce obvious fluorescence signal in three kinds of channels of blue, green and orange, and in the blue channel The fluorescence intensity of is higher than that in the other two channels, again proving the experimental results of the fluorescence emission spectrum. It can be seen from the photos that the fluorescence intensity of PS-BSC microspheres is the highest, that of PS-AC microspheres is slightly weaker, and that of PS-CMME is the weakest, which is consistent with the results of fluorescence spectra.

Claims (6)

1. A method and product of autofluorescence polystyrene material, comprising the following steps: a. Preparation of autofluorescent polystyrene microspheres, Under the action of an acidic catalyst, the benzene ring of polystyrene is acylated or alkylated by Friedel-Crafts reaction to obtain a substance A having the following general formula, Where R can be O=C(CH ₂ ) _n (n=1-18), (CH ₂ ) _n (n=1-4), (CH ₃ ) ₂ CC=O, O ₂ SC ₆ H ₄ , X is H, Cl or Br. The functional group of A is that RX is haloalkyl, haloalkylacyl, alkylacyl, benzenesulfonyl or halobenzenesulfonyl, b. Post-treatment process of autofluorescent polystyrene microspheres, For cross-linked polystyrene microspheres or cross-linked polystyrene plates, first filter the reaction solution in an anhydrous state with a microporous filter membrane, and quickly pour the separated solid matter into glacial hydrochloric acid for stirring, then filter again and use Wash with ionic water until neutral, and finally wash and filter with absolute ethanol, and dry in a vacuum oven to obtain the autofluorescent product. For linear polystyrene, since it is dissolved in the reaction solvent, ethanol or methanol needs to be added after the reaction to precipitate the reaction product and then suction filtered. The subsequent steps are the same as cross-linked polystyrene microspheres or cross-linked polystyrene plates. 2. The method according to claim 1, characterized in that, the polystyrene is cross-linked polystyrene or linear polystyrene. 3. The method according to claim 2, wherein the cross-linked polystyrene is a cross-linked polystyrene microsphere or a cross-linked polystyrene plate. 4. The method according to claim 1, characterized in that the organic solvent described in step 1 is ethers, halogenated alkanes, benzene homologues, ethyl acetate, etc., preferably dichloromethane, dichloroethane, nitro One of benzene or carbon disulfide. 5. The method according to claim 1, wherein the acylating agent described in step 1 is acetyl chloride, acetyl bromide, propionyl chloride, propionyl bromide, butyryl chloride, butyryl bromide, isobutyryl chloride, isobutyryl Any of bromine, chloroacetyl chloride, bromoacetyl bromide, chloropropionyl chloride, bromopropionyl bromide, chlorobutyryl chloride, bromobutyryl bromide, benzenesulfonyl chloride, benzenesulfonyl bromide, chlorobenzenesulfonyl chloride, bromobenzenesulfonyl chloride , the alkylating agent is chloromethyl methyl ether, chloromethyl ether, bromomethyl methyl ether, bromomethyl ether, chloroethyl methyl ether, chloroethyl ether, bromoethyl methyl ether, bromoethyl ether any kind. 6. The method according to claim 1, characterized in that the mol ratio of the acylating agent (alkylating agent) and the reactive benzene ring on the polystyrene microspheres is 0.5-10, preferably 1-3 in step 1. ; The ratio of solvent volume to PS microsphere mass (ml/g) is 5-100, preferably 10-20; the reaction temperature is 0-100°C, preferably 30-60°C; the reaction time is 1-24h, preferably 3-6h.