Preparation Of Molecular Imprinted Polymer And Its Molecular Recognition Function

Molecular imprinting technology(MIT)is a new and potential separation technique for preparing specialized recognition media that is called molecularly imprinted polymer(MIP).MIPs are becoming an important class of synthetic materials mimicking molecular recognition by natural receptors.The process of the preparation consists of:1.mixing the template molecule with a functional monomer having complementary functional groups,2.heat or photo-induced initiation and then polymerization,and 3.extracting the template molecule from the polymer,which leaves cavities inside the polymers that are complementary in terms of size,shape, and functional groups orientation to those of the template molecules.The technique has been applied widely in enantioselective separation,bio-transducer,and simulation of acceptor or antibody,and so on.At present,a variety of techniques have been used to study the preparation of MIP and the applications of MIT in the laboratories.Based on the above statements, in this paper we firstly provide a general introduction and summarization of the research about the MIP.Secondly,2,4-Dichlorophenoxyacetic acid molecularly imprinted polymer(MIP)was prepared by heat initiation and the selective recognition ability of MIP was studied.Quercetin molecularly imprinted polymer(MIP)was prepared by heat initiation and electropolymerization respectively.The MIPs performances were studied.ChapterⅠReviewIn this part,brief reviews are expressed as fellows:1.The basal principle of molecular imprinting technology①Pre-organized Approach②Self-assembly Approach;2.The preparation of molecular imprinting polymer;3.The application of molecular imprinting technology①The application on chromatographic;② MIPs-based sensors;③Solid phase extraction(SPE)with molecularly imprinted materials;④Mimics of antibodies and receptors,enzyme-analogue.The existing problem and developing trend of molecular printing technology have been summed up,which established setting up the problem basis.ChapterⅡStudy on Preparation and Characterization of 2,4-D Molecularly Imprinted Polymer2,4-dichioropheroxyacetic acid(2,4-D)was a kind of herbicide which used normally.It has little toxicity,and its residue existed in soil,environmental water, fruits.So it is important that determination of 2,4-D in environment.MIT used as a new method to detect 2,4-D in this paper.2,4-D molecularly imprinted polymer was prepared using 2,4-D as template molecule,a-methylacrylic acid as functional monomer,2,2'-Azobisisobutyronitrile (AIBN)as initiator and ethylene glycol dimethacrylate(EDMA)as cross-linker.The adsorption performance of MIPs was studied by UV spectrophotometry and selective recognition ability of MIPs was studied by high-performance liquid chromatography (HPLC).Scatchard analysis showed that this MIP could recognize 2,4-D through hydrogen-bond interaction,The maximum number of these binding site and the dissociation constant of MIP toward 2,4-D were 69.7μmol·g^-1and 9.96×10^-3mol·L^-1 respectively.The results of HPLC showed that the imprinted polymer exhibited much higher selectivity for 2,4-D among the tested compounds.ChapterⅢStudy on Preparation and Characterization of Quercetin Molecularly Imprinted PolymerQuercetin is one of Bioflavonoids,which are a large family of organic compounds widely distributed in the plant kingdom.In fact,quercetin have been reported a widely pharmacological properties such as antiviral anti-allergic, anti-plates,anti-inflammatory,and anti-tumor activities,and possibly even protective effect against chronic diseases.In recent decades,molecularly imprinting technique has received a lot of attention for its high affnity to the target molecule.As we know, there were many methods to detect and abstract quercetin.But there were few literatures on detecting quercetin with MIT.In this part,quercetin molecularly imprinted polymer(MIP)was prepared using quercetin as temple molecule,acrylamide as functional monomer.The adsorption performance and selective recognition ability of MIPs were studied by UV spectrophotometry.Scatchard analysis showed that this MIP could recognize quercetin through hydrogen-bond interaction,The results of electrochemical analysis showed that the imprinted polymer exhibited much higher affinity for quercetin among the tested compounds.ChapterⅣChemical Senor for Quercetin Based on Electropolymerized Molecularly Imprinted PolymerBioflavonoids have been reported a widely pharmacological properties such as anti-tumor activities.As we know,there were many methods to detect and abstract quercetin.But there was no literature on preparation of quercetin molecularly imprinted polymer(MIP)by electropolymerization.A chemical sensor for quercetin was prepared by electropolymerization of ortho-phenylenediamine onto the surface of glass-carbon electrode.In conjunction with the use of cyclic voltammetry(CV)and AC impedance measurements,The insulating properties of the sensor were investigated in detail.By differential pulse voltammetry(DPV)the sensor has been investigated on the basis of the change in peak current caused by the analyte which was used as the template in the formulation of an electropolymerized molecularly imprinted polymer as receptor layer. Concentration of quercetin could be detected with a linear determination range up to 2×10^-3mol/L and a detection limit of 5×10^-5mol/L.The results showed that the sensor exhibited a relatively nice selectivity for quercetin among the common coexisting substances.