CN-122006678-A - Temp-pH dual-response tetracycline hydrochloride molecularly imprinted porous hydrogel film, preparation method and application thereof

CN122006678ACN 122006678 ACN122006678 ACN 122006678ACN-122006678-A

Abstract

The invention discloses a temperature-pH dual-response tetracycline hydrochloride molecularly imprinted porous hydrogel film, a preparation method and application thereof, wherein tetracycline hydrochloride is used as a template molecule, acrylic acid, acrylamide and N isopropyl acrylamide are used as a ternary functional monomer copolymerization system, and N, N' -methylene bisacrylamide is used as a cross-linking agent to prepare a prepolymerization solution; adding silicon dioxide microspheres as a pore-forming agent, performing sulfate initiated polymerization to obtain a composite gel film, etching to remove the silicon dioxide microspheres by hydrofluoric acid, and eluting template molecules by an acidic eluent to obtain the tetracycline hydrochloride molecularly imprinted porous gel film. The porous gel membrane provided by the invention can swell and efficiently adsorb the tetracycline hydrochloride at a proper temperature and pH, and rapidly shrink and trigger the controllable release of the tetracycline hydrochloride when the temperature is higher than the phase transition temperature and the pH is adjusted, so that the high-selectivity, rapid mass transfer and intelligent separation of the tetracycline hydrochloride are realized.

Inventors

ZHANG XIN
LI YANSONG
JIAO YUJIE
LIANG JIARONG
XU QIAN
JIAO PENGFEI

Assignees

南阳师范学院

Dates

Publication Date: 20260512
Application Date: 20260409

Claims (10)

1. The preparation method of the tetracycline hydrochloride molecularly imprinted porous hydrogel film with dual temperature-pH response is characterized by comprising the following steps of: (1) Preparing a pore-forming agent, namely hydrolyzing and condensing tetraethoxysilane serving as a silicon source in ethanol solution under the catalysis of ammonia water to obtain monodisperse silicon dioxide nano microspheres; (2) Preparing a casting solution, namely dissolving template molecule tetracycline hydrochloride, a functional monomer, a cross-linking agent and an initiator in ultrapure water to obtain a pre-polymerization solution, adding silica nano-microspheres accounting for 1-10% of the mass of the pre-polymerization solution into the pre-polymerization solution, and uniformly mixing to obtain the casting solution; Wherein the mass volume ratio of the total mass of the functional monomer to the ultrapure water is 5% -20% (g/100 mL), the molar ratio of the template molecule tetracycline hydrochloride to the total functional monomer is 1 (4% -20), the consumption of the cross-linking agent is 1% -10% of the molar amount of the total functional monomer, and the consumption of the initiator is 0.1% -0.8% of the molar amount of the total functional monomer; (3) Film forming and polymerization, namely pouring the film casting solution into a mold or coating the film casting solution on a substrate, and carrying out polymerization reaction under the protection of inert atmosphere to obtain a composite gel film; (4) Removing the pore-forming agent and template molecules, namely etching the composite gel film obtained in the step (3) with a hydrofluoric acid solution with the mass concentration of 1.0% -3.0% for 24h, removing the silicon dioxide nano-microspheres, then flushing with ultrapure water to be neutral to form a porous structure, dynamically eluting for 4% -10 h with an eluent with the pH of 2.0% -4.0 at the constant temperature of 35 ℃ -45 ℃ under the oscillation of 125 rpm, replacing the eluent for two times, fully washing with methanol and water after the elution is completed, and drying with nitrogen at room temperature to obtain the tetracycline hydrochloride molecular imprinting porous hydrogel film with dual response of temperature-pH.
2. The method for preparing the tetracycline hydrochloride molecularly imprinted porous hydrogel membrane with dual response to temperature and pH as claimed in claim 1, which comprises the following steps: (1) Adding absolute ethyl alcohol, ultrapure water and ammonia water into a three-necked flask, wherein the volume ratio of the absolute ethyl alcohol to the ultrapure water to the ammonia water is 65-70:3-4:1, stirring and mixing the absolute ethyl alcohol to the ultrapure water at a constant temperature of 500 rpm ℃ to obtain a mixed solution, slowly dripping ethyl orthosilicate into the mixed solution within 1h, wherein the dripping amount is 4% -5% of the volume of the mixed solution, continuing to react 12 h, centrifuging the obtained milky suspension 8000 rpm for 15 min after the reaction is finished, alternately washing the milky suspension with the ethanol and the ultrapure water for three times, and vacuum drying the milky suspension at 50 ℃ to obtain the monodisperse silica nanoparticle; (2) Preparing a casting solution, namely dissolving template molecule tetracycline hydrochloride and a functional monomer in ultrapure water under a light-shielding condition, magnetically stirring for 30min to fully preassemble, sequentially adding a cross-linking agent and an initiator, continuously stirring until the cross-linking agent and the initiator are fully dissolved to obtain a uniform and transparent prepolymerization solution, adding SiO 2 nano-microspheres accounting for 1-10% of the mass of the prepolymerization solution into the prepolymerization solution, and carrying out ultrasonic treatment for 30min to fully and uniformly disperse the solution to obtain the casting solution; Wherein the mass volume ratio of the total mass of the functional monomer to the ultrapure water is 5% -20% (g/100 mL), the molar ratio of the template molecule tetracycline hydrochloride to the total functional monomer is 1 (4% -20), the consumption of the cross-linking agent is 1% -10% of the molar amount of the total functional monomer, and the consumption of the initiator is 0.1% -0.8% of the molar amount of the total functional monomer; (3) The method comprises the steps of (1) injecting casting solution into a mold or coating the mold on a substrate, placing the mold in a closed container, introducing nitrogen to remove oxygen 15 min, adding an initiator, completing polymerization reaction at room temperature to obtain a composite gel film, (4) removing a pore-forming agent and template molecules, etching 24. 24 h of the composite gel film obtained in the step (3) by using hydrofluoric acid solution with the mass concentration of 1.0% -3.0%, removing silica nano-spheres, flushing the silica nano-spheres to be neutral by using ultrapure water to form a porous structure, dynamically eluting 4-10 h by using eluent with the pH of 2.0-4.0 at the constant temperature of 35-45 ℃ under the oscillation of 125 rpm, changing the eluent twice, fully washing by using methanol and water after the elution is completed, and drying by nitrogen at room temperature to obtain the tetracycline hydrochloride molecularly imprinted hydrogel film with the dual response of temperature-pH.
3. The method for preparing the tetracycline hydrochloride molecularly imprinted porous hydrogel membrane with dual response to temperature and pH according to claim 1, wherein in the step (1), the diameter of the silica nanoparticle is 200 nm-300 nm.
4. The method for preparing the tetracycline hydrochloride molecularly imprinted porous hydrogel membrane with dual response to temperature and pH of claim 1, wherein the cross-linking agent in the step (2) is N, N' -methylenebisacrylamide.
5. The preparation method of the temperature-pH dual-response tetracycline hydrochloride molecularly imprinted porous hydrogel film according to claim 1, wherein the functional monomer in the step (2) is a ternary polymerization system consisting of acrylic acid, acrylamide and N-isopropyl acrylamide, wherein the molar ratio of the acrylic acid, the N-isopropyl acrylamide and the acrylamide is (0.8-2.5): 4.0-7.0): 1.5-3.0.
6. The method for preparing the tetracycline hydrochloride molecularly imprinted porous hydrogel film with dual response to temperature and pH according to claim 1, wherein the initiator in the step (2) is a persulfate system.
7. The method for preparing the tetracycline hydrochloride molecularly imprinted porous hydrogel membrane with dual response to temperature and pH according to claim 1, wherein the eluent in the step (4) is a mixed solution of methanol-acetic acid or ethanol-acetic acid, wherein the volume percentage of acetic acid is 5% -15%.
8. A temperature-pH dual-response tetracycline hydrochloride molecularly imprinted porous hydrogel film, characterized in that it is prepared by the method of any one of claims 1-7.
9. The use of the temperature-pH dual-response tetracycline hydrochloride molecularly imprinted porous hydrogel membrane of claim 8 for enriching or separating tetracycline hydrochloride.
10. The use according to claim 9, comprising passing or contacting a solution containing tetracycline hydrochloride through or in contact with said hydrogel membrane at a temperature below the phase transition temperature of the hydrogel membrane, to effect selective adsorption of the tetracycline hydrochloride, and then eluting at a temperature above the phase transition temperature of the hydrogel membrane and adjusted to a specific pH value to effect rapid release of the tetracycline hydrochloride.

Description

Temp-pH dual-response tetracycline hydrochloride molecularly imprinted porous hydrogel film, preparation method and application thereof Technical Field The invention relates to the technical field of functional polymer materials and natural product separation. In particular to a tetracycline hydrochloride molecularly imprinted porous hydrogel film with dual response of temperature and pH, a preparation method and application thereof. Background Tetracycline hydrochloride is a broad-spectrum antibiotic and is widely used in livestock and poultry farming and human medical treatment. However, due to its low biological metabolic rate, large amounts are excreted in the environment as such or as active metabolites through feces, urine. Residual tetracycline molecules induce bacterial resistance in soil and water and are toxic to aquatic organisms and microbial communities. At present, strict limit standards are formulated for antibiotic residues in environmental water bodies and foods (such as milk and honey) in various countries. Therefore, development of new materials and detection techniques that can efficiently and selectively recognize tetracyclines is an urgent need in the fields of environmental monitoring and food safety. The molecular imprinting technique is capable of preparing a polymer material having a predetermined selectivity for a target molecule. However, the conventional molecularly imprinted polymers are mostly in the form of particles or monolithic columns, and have the defects of large mass transfer resistance and slow binding kinetics, and the identification and release processes of the conventional molecularly imprinted polymers generally lack external controllability. The molecular imprinting technology is combined with an intelligent hydrogel film with environmental responsiveness, so that the novel residual tetracycline separating medium with high selectivity, rapid mass transfer and intelligent controlled release functions is hopeful to be constructed, but related public reports are not found up to the present. Disclosure of Invention Therefore, the technical problem to be solved by the invention is to provide a temperature-pH dual-response tetracycline hydrochloride molecularly imprinted porous hydrogel film, and a preparation method and application thereof, which can effectively solve the problems of large mass transfer resistance, slow binding kinetics and lack of external controllability in the identification and release processes in the existing process of separating and enriching tetracycline residues. In order to solve the technical problems, the invention provides the following technical scheme: The preparation method of the tetracycline hydrochloride molecularly imprinted porous hydrogel film with dual temperature-pH response comprises the following steps: (1) Preparing a pore-forming agent, namely hydrolyzing and condensing tetraethoxysilane serving as a silicon source in ethanol solution under the catalysis of ammonia water to obtain monodisperse silicon dioxide nano microspheres; (2) Preparing a casting solution, namely dissolving template molecule tetracycline hydrochloride, a functional monomer, a cross-linking agent and an initiator in ultrapure water to obtain a pre-polymerization solution, adding silica nano-microspheres accounting for 5-30% of the mass of the pre-polymerization solution into the pre-polymerization solution, and uniformly mixing to obtain the casting solution; Wherein the mass volume ratio of the total mass of the functional monomer to the ultrapure water is 5% -20% (g/100 mL), the molar ratio of the template molecule tetracycline hydrochloride to the total functional monomer is 1 (4% -20), the consumption of the cross-linking agent is 1% -10% of the molar amount of the total functional monomer, and the consumption of the initiator is 0.1% -0.8% of the molar amount of the total functional monomer; (3) Film forming and polymerization, namely pouring the film casting solution into a mold or coating the film casting solution on a substrate, and carrying out polymerization reaction under the protection of inert atmosphere to obtain a composite gel film; (4) Etching the composite gel film obtained in the step (3) with a hydrofluoric acid solution with the mass concentration of 1.0% -3.0% for 24 h to remove silicon dioxide nano-microspheres, then flushing with ultrapure water to neutrality to form a porous structure, dynamically eluting 4% -10 h with an eluent with the pH of 2.0% -4.0 at the constant temperature of 35 ℃ -45 ℃ under the oscillation of 125 rpm, replacing the eluent for two times, fully washing with methanol and water after the elution is completed, drying to constant weight at room temperature, and removing the template molecule tetracycline hydrochloride to obtain the tetracycline hydrochloride molecularly imprinted porous hydrogel film with the dual response of temperature-pH. Further, the method comprises the following steps: (1) Adding abso