CN112934195A

CN112934195A - Photoresponse type molecularly imprinted material and preparation method and application thereof

Info

Publication number: CN112934195A
Application number: CN202110104491.4A
Authority: CN
Inventors: 黄卫红; 佀豪杰; 倪晓霓; 张文文; 张利明; 姬泽华; 徐婉珍
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2021-01-26
Filing date: 2021-01-26
Publication date: 2021-06-11

Abstract

The invention provides a light-responsive molecularly imprinted material and a preparation method and application thereof. In the present invention, a light-responsive molecularly imprinted material based on 4-[(4-methacryloyloxy)azophenyl]benzenesulfonic acid is prepared, and the light-responsive molecularly imprinted material has a uniform particle size The spherical core-shell structure has good light-responsive properties, and cis-trans isomerism occurs at 365nm and 440nm wavelengths; the light-responsive molecularly imprinted material has good light-responsiveness and selectivity, and also overcomes the existing templates. Difficult to elute, incompatibility in aqueous media, low binding capacity and slow mass transfer rate, sulfamethazine has a good application in enrichment/separation of milk.

Description

Photoresponse type molecularly imprinted material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of detection material preparation, and particularly relates to a photoresponse type molecularly imprinted material, and a preparation method and application thereof.

Background

Sulfonamide antibiotics, as a synthetic antibiotic, are widely used for treating diseases of humans and animals due to their advantages of wide antibacterial spectrum, low price, strong antibacterial activity, etc. However, drug residues resulting from overuse accumulate in humans and animals through the food chain, resulting in allergic reactions, renal failure, hepatotoxicity, urinary system diseases, and the like. Sulfamethazine is a sulfonamide antibiotic with wide application and has potential carcinogenic effect. Therefore, the determination of the content of sulfamethazine has important significance. At present, a plurality of methods for detecting sulfonamide antibiotics comprise capillary electrophoresis, immunochemical methods, high performance liquid chromatography and the like. However, the quantitative detection of sulfonamides may be interfered with by other structural analogues in the actual sample. Therefore, a simple, fast, cheap, highly selective affinity material for the isolation of sulfamethazine from complex samples is necessary.

The molecular imprinting has strong molecular recognition capability and is widely applied to systems such as chiral separation, chemical sensing, chemical catalysis, solid phase extraction, drug delivery and the like. However, the traditional molecularly imprinted material has the defects of low utilization rate of binding sites, incomplete elution of templates, large mass transfer resistance and the like. At present, some inorganic supports such as Fe₃O₄Magnetic nanoparticles and SiO₂Although nano particles and the like are widely used as carriers of surface molecular imprinting materials and obtain better performance, the strips which introduce functional groups and remove substrates are difficult to prepareThe piece is not gentle enough.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a photoresponse type molecularly imprinted material and a preparation method and application thereof. In the invention, the photoresponse type molecularly imprinted material based on 4- [ (4-methacryloyloxy) azophenyl ] benzenesulfonic acid is prepared, has good photoresponse and selectivity, overcomes the problems that the existing template is difficult to elute, is incompatible in an aqueous medium, has low binding capacity and slow mass transfer rate, and can be well applied to enrichment/separation of sulfadimidine in milk.

The invention firstly provides a photoresponse type molecularly imprinted material which is prepared on the basis of 4- [ (4-methacryloyloxy) azophenyl ] benzenesulfonic acid; the light response type molecular imprinting material has a spherical core-shell structure with uniform particle size and good light response property, and is subjected to cis-trans isomerism under the conditions of 365nm and 440nm nanometer wavelength.

The invention also provides a preparation method of the photoresponse type molecularly imprinted material, which comprises the following steps:

(1) preparation of 4- [ (4-methacryloyloxy) phenylazo ] benzenesulfonic acid MAPASA:

dissolving sulfanilic acid and potassium carbonate in deionized water, and adding sodium nitrite NaNO₂After cooling, dropwise adding a hydrochloric acid solution, and stirring in an ice-water bath; followed by the addition of a solution containing phenol and K₂CO₃Stirring the mixture in an ice-water bath, adjusting the pH to 2, centrifuging, and washing to obtain 4- [ (4-hydroxy) phenyl ] benzo]Benzenesulfonic acid PABSA;

dissolving N, N-dimethylaminopyridine DMAP, triethylamine and PABSA in tetrahydrofuran THF, dropwise adding chloromethylpropionic acid alkene under the ice water bath condition, stirring, adding saturated saline solution, centrifuging, washing with hydrochloric acid solution, and freeze-drying to obtain the photosensitive monomer MAPASSA.

Further, sulfanilic acid, potassium carbonate, deionized water and NaNO₂The dosage ratio of the components is 7-7.2 g: 5.5-5.7 g: 48-52 ml: 2.9-3.1 g.

Further, in the mixture, NaNO₂Phenol and K₂CO₃The dosage ratio of the components is 2.9-3.1 g: 3.8-4.0 g: 8.9-9.1 g.

Further, the mass ratio of the DMAP to the triethylamine to the PABSA to the chloromethyl propionic acid alkene is 0.14-0.16 g: 4.2-4.4 g: 5.5-5.7 g: 4.4-4.6 g.

(2) Preparing polymethyl methacrylate (PMMA) nano particles:

mixing and stirring methyl methacrylate and ultrapure water, adding potassium persulfate, heating to 80 ℃ in a nitrogen atmosphere, reacting for 24 hours, centrifuging after the reaction is finished, and drying to obtain the polymethyl methacrylate PMMA nano particles.

Further, the using amount ratio of the methyl methacrylate, the ultrapure water and the potassium persulfate is 8-12 ml: 70-90 ml: 0.2-0.3 g.

(3) Preparation of PMMA @ MIPs nanoparticles:

dissolving template molecules of sulfamethazine and MAPASSA in an ethanol water solution, polymerizing under a dark condition, adding a PMMA-dispersed water solution, stirring, adding a crosslinking agent of ethylene glycol dimethacrylate EGDMA and an initiator of potassium persulfate, introducing nitrogen, reacting under the dark condition, centrifuging, washing and drying after the reaction is finished, and finally eluting and drying a dried product by using an acetic acid methanol solution to obtain PMMA @ MIPs nano particles.

The steps (1) and (2) are not in sequence.

Further, the dosage ratio of PMMA, sulfamethazine and MAPASSA is 0.1-0.2 g: 0.08-0.12 mmol: 0.35-0.45 mmol.

Further, the dosage ratio of MAPASA, EGDMA and potassium persulfate is 0.35-0.45 mmol: 1.8-2.2 mmol: 0.08-0.12 g.

Further, the reaction condition is that the reaction is carried out for 24 hours at 70 ℃.

The invention also provides application of the photoresponse type molecular imprinting material in enrichment/separation of sulfamethazine in milk.

Compared with the prior art, the invention has the beneficial effects that:

compared with an inorganic carrier, the core-shell structure imprinted polymer prepared by using PMMA as the carrier saves the step of graft modification, and the preparation step is simpler and more convenient. And compared with inorganic carriers, the method has the advantages of easy introduction of functional groups and mild substrate removing conditions. Meanwhile, the method has larger specific surface area and better adsorption capacity, and can extract sulfamethazine in an actual sample under the condition of low concentration.

In the preparation process, a photosensitive monomer 4- [ (4-methacryloyloxy) azophenyl ] benzenesulfonic acid (MAPASSA) is introduced, has a hydrophilic sulfonic group and an azobenzene structure capable of generating photoisomerization, and can achieve the aim of enriching and detecting sulfadimidine in the environment by changing the irradiation wavelength.

Drawings

FIG. 1 (a) is a scanning electron microscope image of PMMA, (b) is a scanning electron microscope image of PMMA @ MIPs, (c) is a scanning electron microscope image of PMMA @ NIPs, and (d) is a transmission electron microscope image of PMMA @ MIPs.

FIG. 2 is an infrared spectrum of PMMA, PMMA @ MIPs, PMMA @ NIPs.

FIG. 3 is a drawing showing the nitrogen desorption of PMMA @ MIPs and PMMA @ NIPs.

FIG. 4 is a graph of the photoisomerization characteristics of MAPASSA at 365nm (a) and 440 (b), respectively.

FIG. 5 is a graph of the photoisomerization characteristics of PMMA @ MIPs at 365nm, (a) and 440nm, respectively

FIG. 6 is a graph of adsorption isotherms (a) and adsorption kinetics (b) of PMMA @ MIPs and PMMA @ NIPs on sulfamethazine.

FIG. 7 (a) is a Langmuir fit graph of adsorption isotherms, and (b) is a graph showing adsorption selectivity of PMMA @ MIPs and PMMA @ NIPs to sulfadimethy pyrimidine.

Fig. 8 is a graph of light-controlled adsorption release.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

Example 1:

(1) preparation of photosensitive monomer 4- [ (4-methacryloyloxy) phenylazo ] benzenesulfonic acid (MAPASA):

7.0g of sulfanilic acid and 5.5g of potassium carbonate were dissolved in a round-bottomed flask containing 48ml of deionized water, and then 2.9g of sodium nitrite (NaNO) was added₂) Adding into the above mixed solution, stirring, slowly adding dropwise 24ml 5 mol/L hydrochloric acid solution under ice water bath condition, stirring for 1 hr under ice water bath, adding mixture containing 3.8g phenol and 8.9g K₂CO₃Stirring in an ice-water bath and then adjusting the pH to 2, centrifuging, washing and drying to obtain the intermediate 4- [ (4-hydroxy) phenyl ] benzo]Benzenesulfonic acid (PABSA).

0.14g N, N-Dimethylaminopyridine (DMAP), 4.2g triethylamine and 5.5g PABSA were dissolved in 140ml Tetrahydrofuran (THF), 4.4g chloromethylpropionene were added dropwise in an ice-water bath and stirred at 40 ℃ for 24h, followed by addition of 48ml saturated saline solution, centrifugation, washing with hydrochloric acid solution and freeze-drying to give the photosensitive monomer MAPASSA.

(2) Preparation of polymethyl methacrylate (PMMA) nanoparticles:

mixing and stirring 8ml of methyl methacrylate and 70ml of ultrapure water, then adding 0.2g of potassium persulfate KPS, heating to 80 ℃ in a nitrogen atmosphere, reacting for 24 hours, centrifuging and drying after the reaction is finished, and obtaining the polymethyl methacrylate PMMA nano particles.

(3) Preparation of PMMA @ MIPs nanoparticles

Dissolving 0.08mmol of template molecule sulfamethyluracil and 0.35mmol of photosensitive monomer MAPASSA in 30% ethanol aqueous solution by volume fraction, and carrying out polymerization reaction in the dark; dispersing 0.1g of PMMA in 50ml of deionized water, then adding a polymerization reaction solution, uniformly stirring, then adding 1.8mmol of cross-linking agent ethylene glycol dimethacrylate EGDMA and 0.08g of initiator KPS, introducing nitrogen for 30 minutes, and continuously stirring and reacting for 24 hours at 70 ℃ in the dark; after the reaction is finished, obtaining MIPs nano particles through centrifugation, washing and drying, and finally eluting and drying a dried product by using a methanol solution containing 10% acetic acid to obtain PMMA @ MIPs nano particles;

correspondingly, PMMA @ NIPs can be prepared by the method without adding template molecules.

FIG. 1 is a topographical structure of the prepared material, wherein FIG. a is a scanning electron micrograph of PMMA, from which it can be seen that PMMA is a spherical structure with a diameter of about 200 nm. FIGS. b and c are the SEM images of PMMA @ MIPs and PMMA @ NIPs, respectively, from which it can be seen that the material is still spherical after coating with polymer and the diameter increases to 250 nm. And the graph d is a transmission graph of PMMA @ MIPs, and the core-shell structure of the material can be clearly seen from the graph.

Example 2:

7.1g of sulfanilic acid and 5.6g of potassium carbonate were dissolved in a round-bottomed flask containing 48ml of deionized water, and then 3.0g of sodium nitrite (NaNO) was added₂) Adding the mixture into the mixed solution, stirring, slowly dropwise adding 25ml of 5 mol/L hydrochloric acid solution under the condition of ice-water bath to obtain white diazonium salt, and then stirring for 1 hour under the condition of ice-water bath. The mixture obtained above was then slowly added to a solution containing 3.9g of phenol and 9.0g K₂CO₃Stirring and cooling in ice-water bath, adjusting pH to 2, centrifuging, washing, and drying to obtain intermediate 4- [ (4-hydroxy) phenyl group]Benzenesulfonic acid (PABSA).

0.15g 0.15g N, N-Dimethylaminopyridine (DMAP), 4.3g triethylamine and 5.6g PABSA were dissolved in 150ml Tetrahydrofuran (THF), 4.5g chloromethylpropionene were added dropwise in an ice-water bath and stirred at 40 ℃ for 24h, followed by addition of 48ml saturated saline solution, centrifugation, washing with hydrochloric acid solution and freeze-drying to give the photosensitive monomer MAPASSA.

(2) Preparation of polymethyl methacrylate (PMMA) nanoparticles:

mixing and stirring 10ml of methyl methacrylate and 80ml of ultrapure water, then adding 0.25g of potassium persulfate KPS, heating to 80 ℃ in a nitrogen atmosphere, reacting for 24 hours, centrifuging and drying after the reaction is finished, and obtaining the polymethyl methacrylate PMMA nano particles.

(3) Preparation of PMMA @ MIPs nanoparticles:

dissolving 0.1mmol of template molecule sulfamethazine and 0.4mmol of photosensitive monomer MAPASSA in 30% ethanol aqueous solution in the dark for polymerization reaction; dispersing 0.15g of PMMA in 50ml of deionized water, then adding the polymerization reaction liquid, uniformly stirring, then adding 2mmol of crosslinking agent ethylene glycol dimethacrylate EGDMA and 0.1g of initiator KPS, introducing nitrogen for 30 minutes, and continuously stirring and reacting for 24 hours at 70 ℃ in the dark; after the reaction is finished, obtaining MIPs nano particles through centrifugation, washing and drying, and finally eluting and drying a dried product by using a methanol solution containing 10% acetic acid to obtain PMMA @ MIPs nano particles;

FIG. 2 is an infrared spectrum of PMMA, PMMA @ MIPs, PMMA @ NIPs. In the infrared image of PMMA, 1387 cm^-1、1452 cm^-1And 2988 cm^-1The absorption peak is methyl C-H stretching vibration. 2955 cm^-1The typical band of (2) is associated with methylene C-H stretching vibration. At 1150 cm^-1、1259 cm^-1And 1735 cm^-1The strong absorption peak at (a) is C = O of the ester group. The occurrence of these peaks can indicate the success of PMMA preparation. From the IR image of PMMA @ NIPs, it can be seen that the amount of PMMA is 1595 cm more than that of PMMA^-1Peak at C = C representing benzene and 855 cm^-1The peak of the hydrocarbon stretching vibration of benzene indicates that the polymer coats the PMMA surface. The additional 1000 cm can be seen from the infrared image of PMMA @ MIPs^-1The C-H stretching vibration peak of the pyrimidine ring at (C-H), which indicates successful imprinting of the template molecule.

Example 3:

7.2g of sulfanilic acid and 5.7g of potassium carbonate were dissolved in a round-bottomed flask containing 48ml of deionized water, and then 3.1g of sodium nitrite (NaNO) was added₂) Adding the mixture into the mixed solution, stirring, slowly dropwise adding 26ml of 5 mol/L hydrochloric acid solution under the condition of ice-water bath to obtain white diazonium salt, and then stirring for 1 h under the condition of ice-water bath. The mixture obtained above was then slowly added to a solution containing 4.0g of phenol and 9.1g K₂CO₃Is dissolved in waterStirring, cooling in ice-water bath, regulating pH to 2, centrifuging, washing, and drying to obtain intermediate 4- [ (4-hydroxy) phenyl group]Benzenesulfonic acid (PABSA).

0.16g N, N-Dimethylaminopyridine (DMAP), 4.4g triethylamine and 5.7g PABSA were dissolved in 160ml Tetrahydrofuran (THF), 4.6g chloromethylpropionene were added dropwise in an ice-water bath and stirred at 40 ℃ for 24h, followed by addition of 48ml saturated saline solution, centrifugation, washing with hydrochloric acid solution and freeze-drying to give the photosensitive monomer MAPASSA.

(2) Preparation of polymethyl methacrylate (PMMA) nanoparticles:

(3) Preparation of PMMA @ MIPs nanoparticles

Dissolving 0.12mmol of template molecule sulfamethazine and 0.45mmol of photosensitive monomer MAPASSA in 30% ethanol aqueous solution by volume fraction, and carrying out polymerization reaction in the dark; dispersing 0.2g of PMMA in 50ml of deionized water, then adding a polymerization reaction solution, uniformly stirring, then adding 2.2mmol of crosslinking agent ethylene glycol dimethacrylate EGDMA and 0.12g of initiator KPS, introducing nitrogen for 30 minutes, and continuously stirring and reacting for 24 hours at 70 ℃ in the dark; after the reaction is finished, obtaining MIPs nano particles through centrifugation, washing and drying, and finally eluting and drying a dried product by using a methanol solution containing 10% acetic acid to obtain PMMA @ MIPs nano particles;

Example 4:

in the embodiment, 0.1g of PMMA @ MIPs and PMMA @ NIPs are respectively weighed and put into a specific test tube to be dried for 6 hours, and then the test tube is put into a BET specific surface tester to test the nitrogen absorption and desorption capacity of the PMMA @ MIPs and PMMA @ NIPs.

FIG. 3 is a drawing showing the nitrogen desorption of PMMA @ MIPs and PMMA @ NIPs. As can be seen from the figure, two lines of PMMA @ MIPs are not overlapped to form a hysteresis loop, and PMMA @ NIPs do not form a hysteresis loop, which shows that the surface of the PMMA @ MIPs shows a porous structure after elution, and further shows that the template molecules are eluted.

Example 5:

dissolving a certain amount of MAPASSA and PMMA @ MIPs respectively by using a phosphate buffer solution with pH = 7. Then, the solution was placed in a cuvette and irradiated with 365nm wavelength light, and detection was performed with an ultraviolet-visible spectrophotometer every certain period of irradiation until no change was observed. Irradiating the solution with light having a wavelength of 445 nm under 365nm irradiation, and detecting with an ultraviolet-visible spectrophotometer every certain irradiation time until no change is detected.

FIG. 4 is a graph showing the photoisomerization characteristics of MAPASA at different wavelengths, wherein a is the change of absorbance of MAPASA under 365nm wavelength irradiation, and it can be seen from the graph that the absorbance gradually decreases with the increase of irradiation time because MAPASA undergoes cis-trans isomerization and gradually changes from a trans-structure to a cis-structure under 365nm wavelength irradiation, resulting in the decrease of absorbance. FIG. 4b shows the change of absorbance of MAPASA under 440nm wavelength irradiation, and it can be seen that the absorbance gradually increases with the increase of irradiation time because of the change from cis-structure to trans-structure under 440nm irradiation. The two graphs show that MAPASSA has the photo-isomerization characteristic.

FIGS. 5 a and b are the change in absorbance of PMMA @ MIPs under 365nm and 440nm wavelength illumination. The principle is the same as MAPASSA.

Example 6:

respectively dispersing 20 mg of PMMA @ MIPs or PMMA @ NIPs in 5mL of solution with the concentration of 0.02 mmol L^-1-0.16 mmol L^-1Then shaking the solution for 12 hours by a shaking table under the condition of normal temperature and darkness, and centrifuging the solution to obtain supernatant. And finally, detecting the concentration of the supernatant by using high performance liquid chromatography, and further calculating the adsorption capacity.

FIG. 6a is the adsorption isotherm of PMMA @ MIPs and PMMA @ NIPs on sulfamethazine, and it can be seen from the figure that PMMA @ MIPs has better adsorption effect than PMMA @ NIPs because the template molecules form an imprinted cavity after elution, which increases the adsorption performance of the material.

In the embodiment, the adsorption kinetics performances of PMMA @ MIPs and PMMA @ NIPs are also considered, and the method comprises the following steps: respectively dispersing 20 mg of PMMA @ MIPs or PMMA @ NIPs in 5mL of solution with the concentration of 0.1mmol L^-1Then using a shaking table to shake under the condition of normal temperature and darkness and centrifuging at regular intervals to obtain supernatant, and finally using high performance liquid chromatography to detect the concentration of the supernatant.

From fig. 6b, it can be seen that the adsorption capacity of PMMA @ MIPs increases rapidly within 60 minutes, reaching equilibrium around 80 minutes, indicating that PMMA @ MIPs have a faster adsorption rate. This may be due to the use of surface imprinting techniques, which result in the appearance of many imprinted sites on the polymer surface.

Figure 7a is a langmuir fit curve of PMMA @ MIPs adsorption isotherms from which it can be seen from figure 7a that the adsorption model for PMMA @ MIPs conforms to the langmuir model, illustrating that it is a monolayer adsorption.

Example 7:

respectively dispersing PMMA @ MIPs/NIPs (20 mg) in 5ml of 0.2 mmol L^-1After the sulfamethoxazole, sulfamethazine, sulfadiazine and phthalate solution is shaken in a constant temperature shaker for 12 hours, the concentration of the residual medicine in the solution is detected by high performance liquid chromatography.

FIG. 7b is a drawing showing the selectivity of PMMA @ MIPs, and it can be seen from the drawing that PMMA @ MIPs have a better adsorption effect on sulfadimidine, which shows that PMMA @ MIPs have selectivity.

Respectively dispersing 20 mg of PMMA @ MIPs in 0.1mmol L of 5ml^-1The sulfamethoxazole, the sulfamethazine, the sulfadiazine and the phthalate solution are added, then the suspension is cultured for 12 hours in the dark, the radiation is carried out for 2 hours at 365nm, the sulfadimetrazine is released by light control, the centrifugation is carried out after the radiation, and the supernatant is taken for HPLC analysis. For the light-operated adsorption of sulfamethazine, irradiation was carried out at 440nm for 2 h. For other structural analogs, the study procedure was the same as for sulfadimidine.

From fig. 8, it can be seen that the PMMA @ MIPs have good light-operated adsorption and release characteristics, in which the release is performed under 365nm light irradiation and the adsorption is performed under 440nm light irradiation.

The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.

Claims

1. a preparation method of light-responsive molecularly imprinted material, is characterized in that, comprises:

The template molecules sulfamethazine and MAPASA were dissolved in an aqueous ethanol solution, polymerized under dark conditions, and then an aqueous solution dispersed with PMMA was added. After the reaction, centrifugation, washing and drying were performed, and finally the dried product was eluted with methanol solution containing acetic acid and dried to obtain PMMA@MIPs nanoparticles.

2. the preparation method of light-responsive molecularly imprinted material according to claim 1, is characterized in that, described MAPASA is prepared in the following manner: p-sulfanilic acid and potassium carbonate are dissolved in deionized water, then add the Sodium nitrate NaNO ₂ , after cooling, add hydrochloric acid solution dropwise, and stir in an ice-water bath; then add an aqueous solution containing phenol and K ₂ CO ₃ , stir the mixture in an ice-water bath, and adjust the pH to 2, centrifuge, and wash to obtain PABSA;

DMAP, triethylamine and PABSA were dissolved in tetrahydrofuran (THF), and chloromethylpropionic acid was added dropwise in an ice-water bath to stir, then a saturated saline solution was added, centrifuged, washed with hydrochloric acid solution, and freeze-dried to obtain MAPASA.

3. the preparation method of light-responsive molecularly imprinted material according to claim 1, is characterized in that, described polymethyl methacrylate PMMA nano-particle adopts following steps to prepare:

Methyl methacrylate and ultrapure water were mixed and stirred, then potassium persulfate was added, the temperature was raised to 80° C. under nitrogen atmosphere and reacted for 24 hours. After the reaction was completed, centrifugation and drying were performed to obtain polymethyl methacrylate PMMA nanoparticles.

4. The preparation method of light-responsive molecularly imprinted material according to claim 1, wherein the dosage ratio of the PMMA, sulfamethazine and MAPASA is 0.1-0.2g:0.08-0.12mmol:0.35 -0.45mmol.

5. The preparation method of light-responsive molecularly imprinted material according to claim 1, wherein the dosage ratio of the MAPASA, the cross-linking agent and the initiator is 0.35-0.45 mmol: 1.8-2.2 mmol: 0.08-0.12 g.

6 . The method for preparing a light-responsive molecularly imprinted material according to claim 5 , wherein the cross-linking agent is EGDMA, and the initiator is potassium persulfate. 7 .

7 . The method for preparing a light-responsive molecularly imprinted material according to claim 1 , wherein the reaction condition is 70° C. for 24 hours. 8 .

8. The light-responsive molecularly imprinted material prepared by the method according to any one of claims 1 to 7, wherein the light-responsive molecularly imprinted material is based on 4-[(4-methacryloyloxy)azo Phenyl]benzenesulfonic acid MAPASA; the light-responsive molecularly imprinted material has a spherical core-shell structure with uniform particle size, and undergoes cis-trans isomerism under the conditions of 365nm and 440nm nanometer wavelengths.

9. Application of the light-responsive molecularly imprinted material according to claim 8 in enrichment/separation liquid of sulfamethazine.

10. The use according to claim 9, wherein the liquid is milk.