Identification And Detection Of Phenolic Estrogens By Novel Molecularly Imprinted Polymers

Molecularly imprinted polymers(MIPs) are a new kind of smart polymers which can selectively recognize template molecules and effectively concentrate target analytes as well as reduce matrices interferences, and they have been widely applied in many fields such as sample pretreatment, sensors, and drug delivery. In the present thesis, typical phenolic environmental estrogens were selected as template molecules. Molecularly imprinted materials were prepared by non-covalent binding method. The obtained MIPs were used as sorbents, and then combined with fluorescence spectrometry or capillary electrophoresis for the analysis and detection of estradiol and chlorophenols in water environment. The contents of this thesis are as follows:1. Preparation and characterization of estradiol magnetic core-shell imprinted polymers A novel magnetic core-shell composite of Fe3O4 nanoparticles and molecularly imprinted polymers(MIPs) was synthesized by surface imprinting precipitation polymerization with 17β-estradiol as the template molecule. Herein, we characterized the resultant core-shell MIPs by transmission electron microscopy and vibrating sample magnetometer, the results displayed ideal spherical shape and magnetic property. The binding experiment indicated that the obtained core-shell MIPs have high selective adsorption ability to the template molecule.2. Application of estradiol magnetic core-shell imprinted polymers in combination with fluorescence competitive adsorption Fluorescein, which is structurally similar to 17β-E2 with a phenolic hydroxyl group, was used as the fluorescence label. The obtained core-shell MIPs were used for the selective recognition and detection of 17β-estradiol based on molecularly imprinted fluorescent competitive adsorption mechanism. The rebinding of the targets to their recognition sites regulated the release of fluorescein and resulted in the fluorescence enhancement. The increase of fluorescence intensity presented a satisfactory linearity with the concentration of 17β-E2 in the range of 0.10–70 μM, and the limit of detection could reach 0.03 μM. This new strategy was appropriate for selectively recognize and detect non-fluorescent molecules without any derivatization and inducers.3. Molecularly imprinted polymers for the separation and detection of chlorophenols combined with capillary electrophoresis Molecularly imprinted polymers were prepared by precipitation polymerization with 2,4,6-trichlorophenol(2,4,6-TCP) as template. The obtained MIPs displayed ideal spherical shape and uniform particle size. The binding experiment indicated that the obtained MIPs have high adsorption capacity to the target molecules. Various parameters affecting the extraction efficiency were evaluated before the obtained MIPs were used as dispersive solid phase extraction sorbents. Under the optimized conditions, combining MIPs sorbents with capillary electrophoresis for the enrichment, separation and detection of phenol and chlorophenols.