Molecular Imprinted Polymer And Its Application

Molecular imprinting is recognized as a powerful technique to synthesize polymer-type artificial receptors. In this technique, functional monomers and crosslinkers are polymerized in the presence of a template molecule, which is followed by the template removal from the resultant polymer network to leave a template-fitted cavity. The functional monomers used are expected to be complementary to the functional groups of the template molecule through hydrogen bonding, charge interaction, complexing and so on, to form a preorganized supramolecular assembly before polymerization. Consequently, the imprinted polymers exhibit the template-selective binding ability. The molecularly imprinted polymers have been used as chromatographic separation materials, solid phase extractors, catalysts, chemsensors as well as artificial antibodies.Molecularly imprinted polymers were prepared from acrylamide as functional monomers and ethylene glycoldimethacrylate as the cross-linker in chloroform and THF (V₁:V₂=5:10) using genistein as the template molecular and 2,2'-azobis-isobutyronitrile as the initiation agent. The interaction between the template and the monomer was studied at first, which indicated that hydrogen bonding was formed in CHCl₃ and THF. The binding characteristics of the template were evaluated by Scatchard analysis and our results indicated that there were two classes of recognized sites in the polymers and the K_dl=2.43×10^-2mmol/L, Q_max1=28.3μmol/g; K_d2=4.4×10^-2mmol/L, Q_max2=33.6μmol/g. The MIP showed specific affinity toward genistein. The obtained MIP was used as solid phase extractors to extract genistein from the mixture.Uniformly sized molecularly imprinted polymers (MIPs) for genistein have been prepared using ethylene glycoldimethacrylate as a cross-linker and acrylamide as a functional monomer. The MIPs were prepared by different methods and the MIPs on nanometer metatianic acid were the first time applied in the preparation. The SEMs showed that the MIPs prepared by suspension polymerization and on nanometer metatianic acid were spherical and uniformly sized. The adsorption and selective characters of different methods were compared and the results indicated that bulk polymerization shows good adsorption and perfect selectivity. The MIPs were applied on HPLC, when flow-rate was 0.8ml/min, the MIPs prepared by bulk polymerization and suspension polymerization were swollen and reached the limited pressures of apparatus, but MIPs were on nanometer metatianic acid can be used at the same flow-rate. The MIP formatted on nanometer metatianic acid can separate the substrates near-baseline and the imprinted factor was 1.85.An imidacloprid imprinted polymer was synthesized successfully by using acrylic acid as functional monomers and ethylene glycoldimethacrylate as the cross-linker in methanol. The adsorption and selectivity of the polymer was studied. The results indicated that there were two different kinds of recognition sites in the polymer and the MIP showed specific affinity toward imidacloprid, the imprinted factor was 4.34. The polymer packed in SPE column was used to extract imidacloprid residue in garlic.