Preparation And Application Of Vanillin/Bisphenol A Imprinted Polymer And Thermal And Magnetic Dual Responsive Mesoporous Silica For Sophoridine

The contents of this paper could be divided into three parts:(1)Vanillin or Bisphenol A imprinted polymer microspheres were synthesized with precipitation polymerization method and imprinted and recognition mechanism was investigated at the same time.(2)A novel molecularly imprinted photonic hydrogel which was responsive to Bisphenol A was prepared on the combination of photonic crystal and molecular imprinting technique.(3)A novel superparamagnetic mesoporous silica micropheres which was sensitive to temperature was prepared on the combination of superparamagnetic Fe3O4 nanoparticles,mesoporous silica and thermal-sensitive polymer.The details were as following:Molecularly imprinted microspheres(MIPs)were synthesized through precipitation polymerization by using vanillin as the template molecule,methacrylic acid(MAA)as the functional monomer and ethylene glycol dimethacrylate(EGDMA)as the cross-linker in acetonitrile systems.Molecular recognition mechanisms were investigated by UV-Vis Spectrophotometer,Fourier transform infrared spectroscopy(FT-IR)and 1H-NMR techniques.The results showed that hydrogen bond was formed between MAA and vanillin,which played a significant role in the recognition processes of MIPs.The morphology of MIPs were characterized by scanning electron microscope(SEM),the results indicated that the microspheres were uniform spherical morphology with smooth surface.The selective binding capability of MIPs and non-molecularly imprinted polymers(NIPs)for vanillin was tested with binding experiments.The data obtained revealed that the MIPs reached equilibrium adsorption after 120 min and had a higher affinity and selectivity for vanillin than NIPs.Scatchard analysis showed the homogeneous recognition sites for Vanillin were formed in MIPs,the dissociation contents and the apparent maximum binding capacity were Kd=4.243×10-5mol/L,Qmax=7.357 ?mol/g,respectively;The selective separation,solid phase extraction(SPE)and high-performance liquid chromatography(HPLC)experiments were performed to investigate the separation,enrichment and purification properties of the MIPs for Vanillin,the data revealed that MIPs can be used as an excellent solid-phase sorbent to separate and enrich Vanillin from complicated foods.Bisphenol A(2,2-bis(4-hydroxyphenyl)propane,BPA)molecularly imprinted polymers(MIPs)were synthesized by precipitation polymerization method with BPA as the template molecule,4-VP as the functional monomer and Trimethylolpropane trimethacrylate(TRIM)as the cross-linker.Interaction between BPA and 4-VP was investigated by UV and FT-IR techniques,The morphology of MIPs was observed with SEM.The results showed that a 1:2 cooperative H-bonding interaction was the main interaction between BPA and 4-VP in the pre-polymerization,the morphology of MIPs was the uniform and irregularly particles with smooth surface.Adsorption results revealed that the MIPs have a higher affinity and selectivity for BPA than non-molecularly imprinted polymers(NIPs).Scatchard analysis indicated that the homogeneous binding sites of BPA were formed in MIPs,the maximum adsorption amounts and the equilibrium dissociation constant were Qmax=28.83 ?mol/g,Kd=0.3112 ?mol/L,respectively.SPE analyses showed that MIPs had more efficiency,higher specificity and selectivity for BPA;so it could be applied for separation,concentration and determination of BPA from complicated food samples.A novel molecularly imprinted photonic hydrogel(MIH)for the high sensitive and rapid detection of BPA was constructed with the incorporation of photonic crystal and molecular imprinting technique.The MIH was prepared by UV lights with BPA as the template molecular,MAA as functional monomer.The surface characterization and response performance of MIH was investigated by SEM and UV-Vis Spectrophotometer;the results showed that MIH possessed a highly ordered three-dimensional(3-D)interconnected macroporous structure;the bragg diffraction peak migrated from 597 nm to 569 nm when the concentration of BPA was aumented from 10-15 to 10-6 mol/L,however there was little peak shifts for tetrabromobisphenol A and nonimprinted photonic hydrogel(NIH)was no response to BPA yet,demonstrating that MIH was rapid responsive,high selective and sensitive to BPA.The application prospect of MIH in the field of food was wide due to its handy and quick detection of trace analyte.A novel magnetic and thermal-responsive mesoporous silica nanoparticles(M-MSNs-PNIPAM)was developed as a drug delivery carrier by using magnetic Fe3O4 nanoparticle as the core,mesoporous silica nanoparticles as the sandwiched layer and thermal-responsive polymers(N-isopropylacrylamide)(PNIPAAm)as the outer shell,respectively.The characteristics of M-MSNs-PNIPAAm were investigated by Transmission electron microscopy(TEM),FT-IR,X-ray diffraction(XRD),Thermogravimetric analyzer(TGA),N2 adsorption-desorption isotherm and Vibrating specimen magnetometer(VSM).The results indicated that Fe3O4 nanoparticles were incorporated into mesoporous silica nanospheres(M-MSNs),and PNIPAAm was grafted onto the surface of M-MSNs via precipitation polymerization.The obtained M-MSNs-PNIPAAm possessed superparamagnetic characteristics with high surface areas,large pore volume and size.Sophoridine was used as a drug model,to investigate the loading and releasing properties under different temperatures.The results demonstrated that the PNIPAAm layers on the surface of M-MSNs-PNIPAAm could effectively regulate uptake and release of sophoridine.The application of such dual responsive carrier might offer a potential platform for controlled and targeted delivery of drugs.