Preparation method and application of surface molecularly imprinted polymer for selectively adsorbing norfloxacin

Abstract

The invention relates to filtration and adsorption of a high polymer material and norfloxacin, in particular to a preparation method and application of a surface molecularly imprinted polymer for selectively adsorbing norfloxacin, cobalt nitrate hexahydrate is used as a cobalt source, terephthalic acid (PTA) is used as an organic ligand, N, N '-dimethylformamide (DMF) and absolute ethyl alcohol are used as solvents, multi-walled carbon nanotubes (MWCNTs) are added, and the surface molecularly imprinted polymer for selectively adsorbing norfloxacin is prepared. The Co-MOF / MWCNT is synthesized by adopting a solvothermal method. The surface molecularly imprinted polymer MIP-MOF / MWCNT which has good adsorption performance and high selectivity on a template norfloxacin is prepared by taking a metal organic framework / MWCNT as a matrix and carrying out molecular imprinting on the surface of the matrix. The polymer prepared by the method has high adsorption capacity on norfloxacin.

Description

Technical Field

[0001] The invention relates to polymer materials and filtration adsorption of norfloxacin, and in particular to a preparation method and application of a surface molecular imprinting polymer for selectively adsorbing norfloxacin. Background Art

[0002] Norfloxacin is a quinolone antibiotic that has an inhibitory effect on bacteria. It is widely used because of its obvious efficacy in humans and animals and its low price (Chen MJ, Zhao LY, Shi XJ, Wang W, Huang Y, FuL J, Ma L J. Chinese Chemical Letters, 2024, 35: 109336). However, in the body, norfloxacin cannot be completely absorbed and decomposed, and will return to the environment without being degraded, seriously affecting the ecological environment and biological health (Zhang YL, Jamal R, Abdurexit A, Abdiryim T, Zhang Y, Zhou YQ, Liu YJ, FanN N, Wang Z G. Composites Part B: Engineering, 2024, 279: 111432). Long-term exposure to norfloxacin can affect intestinal health, cause severe oxidative stress, cause liver and neurotoxicity, have a significant impact on the health and metabolism of symbionts, and lead to dysbiosis (Huang ML, Ma YX, Qian J, Sokolova IM, Zhang CQ, Waiho K, Fang JKH, Ma XW, Wang YJ, Hu MH. Journal Of Hazardous Materials, 2024, 468: 133801). Conventional enrichment methods for norfloxacin include high performance liquid chromatography, solid phase extraction, macroporous resin adsorption, etc. However, these traditional methods often have problems such as cumbersome processes and high pretreatment requirements. Molecular imprinting technology can prepare molecularly imprinted polymers that have specific recognition for template molecules, and at the same time have the advantages of easy preparation, low cost, high chemical and mechanical stability. Using molecular imprinting technology, norfloxacin can be selectively adsorbed efficiently and quickly.

[0003] Metal organic frameworks (MOFs) are a new type of porous crystalline material with a two-dimensional or three-dimensional network structure that is self-assembled by metal clusters / ions and organic ligands with coordination bonds through a variety of synthetic strategies (Tang J, Huang CY, Liu YQ, Wang TQ, Yu M, Hao HS, Zeng WW, Huang WX, Wang JQ, Wu M Y. Coordination Chemistry Reviews, 2023, 490: 215211). The structure of MOF can be regulated by selecting different combinations of metal cations and organic linkers and performing modification treatments (Payam AF, Khalil S, Chakrabarti S. Small, 2024, 20: e2310348). MOF materials have the advantages of high porosity, large surface area, high thermal stability and a large amount of pore volume, and have attracted widespread attention in various fields (Mao LJ, Qian JJ. Small, 2024, 20: e2308732). The combination of metal-organic framework materials, multi-walled carbon nanotubes and molecular imprinting technology makes the polymer have a larger specific surface area, which can form more specific recognition sites and improve the adsorption and selectivity of the template molecule norfloxacin. Summary of the invention

[0004] The technical problem to be solved by the present invention is: how to provide a surface molecular imprinting polymer for selectively adsorbing norfloxacin.

[0005] The technical solution adopted by the present invention is: a method for preparing a surface molecular imprinted polymer for selectively adsorbing norfloxacin, comprising the following steps: Step 1, preparation of metal organic framework material MOF / multi-walled carbon nanotube matrix (Co-MOF / MWCNT), adding terephthalic acid (PTA) to a mixed solution of N, N-dimethylformamide (DMF) and anhydrous ethanol and stirring evenly, adding cobalt nitrate hexahydrate and multi-walled carbon nanotubes (MWCNT) and continuing to stir to form a suspension, transferring the suspension to a reactor for reaction, and after the reaction is completed, washing with N, N-dimethylformamide (DMF) and anhydrous ethanol alternately, vacuum filtering, and drying to obtain a metal organic framework material MOF / multi-walled carbon nanotube matrix (Co-MOF / MWCNT); Step 2, preparation of imprinted polymer (MIP-MOF / MWCNT), the template molecule norfloxacin and the functional monomer 3-aminopropyltriethoxysilane (APTES) are stirred in anhydrous ethanol for 25-45 min for pre-polymerization, ethyl silicate (TEOS) is added and stirring is continued, and then (Co-MOF / MWCNT) and ammonia water are added to continue the reaction. After the reaction is completed, it is repeatedly washed with a mixed solvent until the template molecule norfloxacin can no longer be detected in the eluent, and vacuum filtration and drying are performed to obtain the imprinted polymer (MIP-MOF / MWCNT), that is, the surface molecular imprinted polymer that selectively adsorbs norfloxacin.

[0006] In step 1, every 10 mL of N,N-dimethylformamide DMF corresponds to 2.5 mL of anhydrous ethanol, 0.13-0.33 g of terephthalic acid PTA, 0.3-0.6 g of cobalt nitrate hexahydrate and 0.1-0.3 g of multi-walled carbon nanotubes MWCNT, the total stirring time is 30-60 min, the reactor is a polytetrafluoroethylene-lined autoclave, the reaction temperature is 95-105°C, the reaction time is 10-14 h, the drying temperature is 45-60°C, and the drying time is 6-8 h.

[0007] In step 2, every 12 mL of anhydrous ethanol corresponds to 0.01-0.03 g of template molecule norfloxacin, 0.067-0.885 mL of functional monomer 3-aminopropyltriethoxysilane APTES, 1.67-4.16 mL of ethyl silicate TEOS, 0.04-0.1 g of metal organic framework material MOF / multi-walled carbon nanotube matrix Co-MOF / MWCNT and 8 mL of ammonia water. After adding ammonia water, the reaction is continued for 10-14 h.

[0008] In step 2, the mixed solvent is a mixed solution formed by mixing acetic acid and methanol in a volume ratio of 2:3.

[0009] The invention discloses an application of a surface molecular imprinting polymer for selectively adsorbing norfloxacin. The surface molecular imprinting polymer for selectively adsorbing norfloxacin is used for selectively adsorbing norfloxacin.

[0010] The beneficial effects of the present invention are as follows: (1) The molecular imprinting polymer MIP-MOF / MWCNT is prepared by combining metal organic framework / multi-walled carbon nanotubes with molecular imprinting technology. MIP-MOF / MWCNT selectively adsorbs norfloxacin, and the saturated adsorption amount reaches 140.1 mg / g. The saturated adsorption amounts of enrofloxacin and ciprofloxacin, which are structural similarities of norfloxacin, are 22.8 mg / g and 28.9 mg / g. (2) The molecular imprinting polymer MIP-MOF / MWCNT prepared by the present invention has both the large specific surface area of ​​metal organic framework / multi-walled carbon nanotubes and the specific recognition selectivity and high binding affinity of molecular imprinting polymers. (3) The preparation method of molecular imprinting polymer MIP-MOF / MWCNT is simple and easy to operate, low in price, has a certain ability to resist harsh environments, is highly stable and renewable, and exhibits good selective adsorption and high adsorption amount for norfloxacin in the environment. DETAILED DESCRIPTION Example

[0011] 0.23 g PTA was added to 10 mL DMF and 2.5 mL anhydrous ethanol and stirred for 10 min. 0.4 g cobalt nitrate hexahydrate and 0.15 g MWCNT were added and stirred for 30 min. The suspension was transferred to a polytetrafluoroethylene-lined autoclave and reacted at 100 °C for 12 h. After the reaction was completed, it was washed alternately with DMF and anhydrous ethanol, vacuum filtered, and dried at 50 °C for 6 h to obtain Co-MOF / MWCNT. 0.014 g norfloxacin and 0.7 mL APTES were stirred in 12 mL anhydrous ethanol for 25 min for prepolymerization, and 2 mL TEOS was added and continued to stir. Subsequently, 0.045 g Co-MOF / MWCNT and 8 mL ammonia were added and the reaction was continued for 12 h. After the reaction was completed, it was repeatedly washed with a mixed solvent of acetic acid and methanol (V:V=2:3) until the template molecule norfloxacin could not be detected in the eluent, vacuum filtered, and dried at 50 °C for 6 h to obtain the imprinted polymer MIP-MOF / MWCNT. At the same time, a non-imprinted polymer NIP was prepared in the same manner as above except that the template molecule norfloxacin was not added.

[0012] To 30 mL of DMF solution of norfloxacin with an initial concentration of 1.5 mg / g, 0.03 g of imprinted polymer MIP-MOF / MWCNT and non-imprinted polymer NIP were added into a conical flask, placed in a constant temperature oscillator, and oscillated at 25°C for 6 h. The saturated adsorption capacity of the imprinted polymer MIP-MOF / MWCNT can reach 140.1 mg / g, and the saturated adsorption capacity of the non-imprinted polymer NIP is 84 mg / g. 0.02 g of enrofloxacin and ciprofloxacin were added to 20 mL of DMF solution of norfloxacin with an initial concentration of 1 mg / g, respectively, and the mixture was evenly mixed. Then, 0.03 g of imprinted polymer MIP-MOF / MWCNT was accurately weighed and added to a conical flask. The flask was placed in a constant temperature oscillator and oscillated at 25°C for 6 h. The saturated adsorption capacity of enrofloxacin and ciprofloxacin by the imprinted polymer MIP-MOF / MWCNT was 22.8 mg / g and 28.9 mg / g respectively. Example

[0013] 0.23 g PTA was added to 10 mL DMF and 2.5 mL anhydrous ethanol and stirred for 10 min. 0.4 g cobalt nitrate hexahydrate and 0.15 g MWCNT were added and stirred for 30 min. The suspension was transferred to a polytetrafluoroethylene-lined autoclave and reacted at 100 °C for 12 h. After the reaction was completed, it was washed alternately with DMF and anhydrous ethanol, vacuum filtered, and dried at 50 °C for 6 h to obtain Co-MOF / MWCNT. 0.03 g norfloxacin and 0.7 mL APTES were stirred in 12 mL anhydrous ethanol for 25 min for prepolymerization, and 2 mL TEOS was added and continued to stir. Subsequently, 0.045 g Co-MOF / MWCNT and 8 mL ammonia were added and the reaction was continued for 12 h. After the reaction was completed, it was repeatedly washed with a mixed solvent of acetic acid and methanol (V:V=2:3) until the template molecule norfloxacin could not be detected in the eluent, vacuum filtered, and dried at 50 °C for 6 h to obtain the imprinted polymer MIP-MOF / MWCNT. At the same time, a non-imprinted polymer NIP was prepared in the same manner as above except that the template molecule norfloxacin was not added.

[0014] To 30 mL of DMF solution of norfloxacin with an initial concentration of 1.5 mg / g, 0.03 g of imprinted polymer MIP-MOF / MWCNT and non-imprinted polymer NIP were added into a conical flask, respectively, and placed in a constant temperature oscillator and oscillated at 25°C for 6 h. The saturated adsorption capacity of the imprinted polymer MIP-MOF / MWCNT can reach 104.7 mg / g, and the saturated adsorption capacity of the non-imprinted polymer NIP is 61.2 mg / g. 0.02 g of enrofloxacin and ciprofloxacin were added to 20 mL of DMF solution of norfloxacin with an initial concentration of 1 mg / g, respectively, and the mixture was evenly mixed. Then, 0.03 g of imprinted polymer MIP-MOF / MWCNT was accurately weighed and added to a conical flask. The flask was placed in a constant temperature oscillator and oscillated at 25°C for 6 h. The saturated adsorption capacity of enrofloxacin and ciprofloxacin by the imprinted polymer MIP-MOF / MWCNT was 17.7 mg / g and 24.5 mg / g respectively. Example

[0015] 0.23 g PTA was added to 10 mL DMF and 2.5 mL anhydrous ethanol and stirred for 10 min. 0.4 g cobalt nitrate hexahydrate and 0.1 g MWCNT were added and stirred for 30 min. The suspension was transferred to a polytetrafluoroethylene-lined autoclave and reacted at 100 °C for 12 h. After the reaction was completed, it was washed alternately with DMF and anhydrous ethanol, vacuum filtered, and dried at 50 °C for 6 h to obtain Co-MOF / MWCNT. 0.014 g norfloxacin and 0.7 mL APTES were stirred in 12 mL anhydrous ethanol for 25 min for prepolymerization, and 2 mL TEOS was added and continued to stir. Subsequently, 0.04 g Co-MOF / MWCNT and 8 mL ammonia were added and the reaction was continued for 12 h. After the reaction was completed, it was repeatedly washed with a mixed solvent of acetic acid and methanol (V:V=2:3) until the template molecule norfloxacin could not be detected in the eluent, vacuum filtered, and dried at 50 °C for 6 h to obtain the imprinted polymer MIP-MOF / MWCNT. At the same time, a non-imprinted polymer NIP was prepared in the same manner as above except that the template molecule norfloxacin was not added.

[0016] To 30 mL of DMF solution of norfloxacin with an initial concentration of 1.5 mg / g, 0.03 g of imprinted polymer MIP-MOF / MWCNT and non-imprinted polymer NIP were added into a conical flask, placed in a constant temperature oscillator, and oscillated at 25°C for 6 h. The saturated adsorption capacity of the imprinted polymer MIP-MOF / MWCNT can reach 115.2 mg / g, and the saturated adsorption capacity of the non-imprinted polymer NIP is 68.5 mg / g. 0.02 g of enrofloxacin and ciprofloxacin were added to 20 mL of DMF solution of norfloxacin with an initial concentration of 1 mg / g, respectively, and the mixture was evenly mixed. Then, 0.03 g of imprinted polymer MIP-MOF / MWCNT was accurately weighed and added to a conical flask. The flask was placed in a constant temperature oscillator and oscillated at 25°C for 6 h. The saturated adsorption capacity of enrofloxacin and ciprofloxacin by the imprinted polymer MIP-MOF / MWCNT was 20.9 mg / g and 23.7 mg / g respectively. Example

[0017] 0.23 g PTA was added to 10 mL DMF and 2.5 mL anhydrous ethanol and stirred for 10 min. 0.4 g cobalt nitrate hexahydrate and 0.15 g MWCNT were added and stirred for 30 min. The suspension was transferred to a polytetrafluoroethylene-lined autoclave and reacted at 100 °C for 12 h. After the reaction was completed, it was washed alternately with DMF and anhydrous ethanol, vacuum filtered, and dried at 50 °C for 6 h to obtain Co-MOF / MWCNT. 0.014 g norfloxacin and 0.7 mL APTES were stirred in 12 mL anhydrous ethanol for 25 min for prepolymerization, and 2 mL TEOS was added and continued to stir. Subsequently, 0.045 g Co-MOF / MWCNT and 8 mL ammonia were added and the reaction was continued for 12 h. After the reaction was completed, it was repeatedly washed with a mixed solvent of acetic acid and methanol (V:V=2:3) until the template molecule norfloxacin could not be detected in the eluent, vacuum filtered, and dried at 50 °C for 6 h to obtain the imprinted polymer MIP-MOF / MWCNT. At the same time, a non-imprinted polymer NIP was prepared in the same manner as above except that the template molecule norfloxacin was not added.

[0018] To 30 mL of DMF solution of norfloxacin with an initial concentration of 1.5 mg / g, 0.03 g of imprinted polymer MIP-MOF / MWCNT and non-imprinted polymer NIP were added into a conical flask, placed in a constant temperature oscillator, and oscillated at 45°C for 6 h. The saturated adsorption capacity of the imprinted polymer MIP-MOF / MWCNT can reach 71.8 mg / g, and the saturated adsorption capacity of the non-imprinted polymer NIP is 46.3 mg / g. 0.02 g of enrofloxacin and ciprofloxacin were added to 20 mL of DMF solution of norfloxacin with an initial concentration of 1 mg / g, respectively, and the mixture was evenly mixed. Then, 0.03 g of imprinted polymer MIP-MOF / MWCNT was accurately weighed and added to a conical flask. The flask was placed in a constant temperature oscillator and oscillated at 45 °C for 6 h. The saturated adsorption capacity of enrofloxacin and ciprofloxacin by the imprinted polymer MIP-MOF / MWCNT was 16.8 mg / g and 18.2 mg / g respectively. Example

[0019] 0.23 g PTA was added to 10 mL DMF and 2.5 mL anhydrous ethanol and stirred for 10 min. 0.4 g cobalt nitrate hexahydrate and 0.15 g MWCNT were added and stirred for 30 min. The suspension was transferred to a polytetrafluoroethylene-lined autoclave and reacted at 100 °C for 12 h. After the reaction was completed, it was washed alternately with DMF and anhydrous ethanol, vacuum filtered, and dried at 50 °C for 6 h to obtain Co-MOF / MWCNT. 0.014 g norfloxacin and 0.885 mL APTES were stirred in 12 mL anhydrous ethanol for 25 min for prepolymerization, and 4.16 mL TEOS was added and continued to stir. Subsequently, 0.045 g Co-MOF / MWCNT and 8 mL ammonia were added to continue the reaction. After the reaction was completed, it was repeatedly washed with a mixed solvent of acetic acid and methanol (V:V=2:3), vacuum filtered, and dried at 50 °C for 6 h to obtain the imprinted polymer MIP-MOF / MWCNT. At the same time, a non-imprinted polymer NIP was prepared in the same manner as above except that the template molecule norfloxacin was not added.

[0020] To 30 mL of DMF solution of norfloxacin with an initial concentration of 1.5 mg / g, 0.03 g of imprinted polymer MIP-MOF / MWCNT and non-imprinted polymer NIP were added into a conical flask, placed in a constant temperature oscillator, and oscillated at 25°C for 6 h. The saturated adsorption capacity of the imprinted polymer MIP-MOF / MWCNT can reach 98.5 mg / g, and the saturated adsorption capacity of the non-imprinted polymer NIP is 57.1 mg / g. 0.02 g of enrofloxacin and ciprofloxacin were added to 20 mL of DMF solution of norfloxacin with an initial concentration of 1 mg / g, respectively, and the mixture was evenly mixed. Then, 0.03 g of imprinted polymer MIP-MOF / MWCNT was accurately weighed and added to a conical flask. The flask was placed in a constant temperature oscillator and oscillated at 25°C for 6 h. The saturated adsorption capacity of enrofloxacin and ciprofloxacin by the imprinted polymer MIP-MOF / MWCNT was 15.6 mg / g and 18.8 mg / g respectively.

Claims

1. A method for preparing a surface molecularly imprinted polymer for selectively adsorbing norfloxacin, characterized in that: The steps include: Step 1, preparation of metal organic framework material MOF / multi-walled carbon nanotube matrix Co-MOF / MWCNT, adding terephthalic acid PTA to a mixed solution of N,N-dimethylformamide DMF and anhydrous ethanol and stirring evenly, adding cobalt nitrate hexahydrate and multi-walled carbon nanotubes MWCNT and continuing to stir to form a suspension, transferring the suspension to a reactor for reaction, and after the reaction is completed, washing with N,N-dimethylformamide DMF and anhydrous ethanol alternately, vacuum filtering, and drying to obtain the metal organic framework material MOF / multi-walled carbon nanotube matrix Co-MOF / MWCNT; Step 2, preparation of imprinted polymer MIP-MOF / MWCNT, the template molecule norfloxacin and the functional monomer 3-aminopropyltriethoxysilane APTES are stirred in anhydrous ethanol for 25-45 min for pre-polymerization, ethyl silicate TEOS is added and continued to stir, and then Co-MOF / MWCNT and ammonia water are added to continue the reaction. After the reaction is completed, it is repeatedly washed with a mixed solvent until the template molecule norfloxacin is no longer detected in the eluent, and vacuum filtration and drying are performed to obtain the imprinted polymer MIP-MOF / MWCNT, that is, a surface molecular imprinting polymer that selectively adsorbs norfloxacin.

2. The method for preparing a surface molecularly imprinted polymer for selectively adsorbing norfloxacin according to claim 1, characterized in that: In step 1, every 10 mL of N,N-dimethylformamide DMF corresponds to 2.5 mL of anhydrous ethanol, 0.13-0.33 g of terephthalic acid PTA, 0.3-0.6 g of cobalt nitrate hexahydrate and 0.1-0.3 g of multi-walled carbon nanotubes MWCNT, the total stirring time is 30-60 min, the reactor is a polytetrafluoroethylene-lined autoclave, the reaction temperature is 95-105°C, the reaction time is 10-14 h, the drying temperature is 45-60°C, and the drying time is 6-8 h.

3. The method for preparing a surface molecularly imprinted polymer for selectively adsorbing norfloxacin according to claim 1, characterized in that: In step 2, every 12 mL of anhydrous ethanol corresponds to 0.01-0.03 g of template molecule norfloxacin, 0.067-0.885 mL of functional monomer 3-aminopropyltriethoxysilane APTES, 1.67-4.16 mL of ethyl silicate TEOS, 0.04-0.1 g of metal organic framework material MOF / multi-walled carbon nanotube matrix Co-MOF / MWCNT and 8 mL of ammonia water. After adding ammonia water, the reaction is continued for 10-14 h.

4. The method for preparing a surface molecularly imprinted polymer for selectively adsorbing norfloxacin according to claim 1, characterized in that: In step 2, the mixed solvent is a mixed solution formed by mixing acetic acid and methanol in a volume ratio of 2:

3.

5. Use of a surface molecularly imprinted polymer that selectively adsorbs norfloxacin prepared by the method for preparing a surface molecularly imprinted polymer that selectively adsorbs norfloxacin according to any one of claims 1 to 4, characterized in that: The surface molecular imprinting polymer for selectively adsorbing norfloxacin is used for selectively adsorbing norfloxacin.