Preparation And Properties Of Surface Molecularly Imprinted Materials

Molecular imprinting technology can prepare molecularly imprinted polymers with the same function as the target molecules.This polymer has Similar characteristics of biological receptors,can combine with monomers and can replace some bioactive substances.This technique is widely used in chromatographic analysis,drug analysis and catalysis.It is a promising research field in the 21st century.1.Restricted molecularly imprinted polymers for the selective separationA novel limited access medium molecularly imprinted polymer（RAM-MIPs）was prepared by Si-ATRP technique.Dopamine（DA）molecularly imprinted polymer（MIPs）was grafted onto the surface of Polyglycidyl methacrylate-co-ethyl dimethacrylate（Poly（GMA-co-EGDMA））microspheres to achieve the specific recognition and sensitive determination of trace dopamine in urine samples.RAM-MIPs can specifically adsorb target molecules in urine sampleand effectively eliminate the interference of protein macromolecules.RAM-MIPs were prepared using DA as template phenylboric acid as functional monomer,methanol-acetonitrile（1:1,v/v）as solvent,ethylene glycol dimethacrylate（EGDMA）as a cross-linking agent,and Cu Br as catalyst.RAM-MIPs were characterized by Fourier transform infrared spectroscopy（FT-IR）,elemental analysis,scanning electron microscopy（SEM）.High performance liquid chromatography（HPLC-UV）was used to extract DA from urine samples.Under optimal conditions,the established method has good linearity（R²>0.9995）.For urine samples,the LOD is 2.52μ.The relative standard deviation（RSD）of g/m L is not higher than 5.1,and the recovery rate is not lower than 83.4%.Imprinted materials have good reusability and provide an improved strategy for selectively extracting and detecting target molecules directly from complex samples.2.Preparation and application of Pefloxacin magnetic molecularly imprinted polymerMagnetic moleculally-imprinted polymers（MMIPs）were prepared by ATRP technique using superparamagnetic Fe₃O₄as magnetic core,Pefloxacin（PEF）as template molecule,AIBN as initiator and EGDMA as crosslinking agent.The maximum adsorption capacity of PEF-MMIPs and PEF-MNIPs was 14.97 mg/g and 10.44 mg/g respectively through static adsorption experiment.The adsorption equilibrium of PEF-MMIPs was basically reached through dynamic adsorption experiment in about 30min and its saturated adsorption capacity was 40.85 mg/g respectively.Ciprofloxacin（CIP）,Gatifloxacin（GTFX）,Oxytetracycline（OTC）and phenol were selected as the structural equivalents of PEF to test the selective adsorption properties of PEF-MMIPs and PEF-MNIPs on the template molecule PEF.The results showed that the synthesized magnetic imprinted polymer can recognize PEF specifically.The LOD and LOQ obtained from the Signal-to-noise ratio of 3 and 10 are 1.2428μg/L,6.094μg/L,respectively.the R²of PEF is 0.9990.These satisfactory results further demonstrate the high sensitivity and satisfactory precision of the PEFMMIPs-DSPE-HPLC method,which can be used for the analysis of trace PEF in samples.3.Preparation and properties of molecularly imprinted polymer of4-methylumbelumyl-β-D-gluco Sidic acid hydrate imprinted materialA Simple,efficient and rapid method for the determination of 4-methylumbelliferone-β-D-glucosidate hydrate（MUG）was presented.With spherical Silica gel as the substrate,MAA as the functional monomer,MUG as the template molecule,Si-ATRP technology was used to graft a layer of imprinting layer that can specifically recognize the target molecule MUG on its surface,and static adsorption experiments were conducted to obtain the results of Mug-MIPs and Mug-NIPs in the standard solution with a concentration of 10μg/m L.The saturated adsorption capacity can be reached and the adsorption capacity is204.78μg/g and 111.46μg/g,respectively.The dynamic adsorption experiment shows that the adsorption equilibrium is reached when the adsorption time is about 70 min and the equilibrium adsorption capacity is 197.31μg/g and 134.26μg/g,respectively.7-hydroxycoumarin-4-acetic acid（HAC）7,8-dihydroxy-4-methyl coumarin（DMC）and phenol were selected as the structural analogues of MUG to test the selective adsorption properties of Mug-MIPs and Mug-Nips on the template molecule MUG.The results showed that the synthesized surface molecularly imprinted polymer can recognize MUG specifically.The established method has a good linearity（R2 0.9992）,and the detection limit（LOD）and quantification limit（LOQ）of MUG are 1.89μg/L（three times the Signal-to-noise ratio）and 9.45μg/L（10 times the Signal-to-noise ratio）.