Application Research Of Piezoelectric Biomimic Sensor With Molecular Imprinted Polymer Coating

Recently, simple, inexpensive, real time and speediness piezoelectric sensors have gained popularity over more complicated traditional analytical methods and techniques.The core part of piezoelectric sensors is the recognition element,. which is generally made up of biologic molecular. However most biologic molecular is remarkably unstable and the low storage endurance. Therefor, it is necessary to find a material with high selectivity and a long life.The molecular imprinting technology(MIT) for preparing an antibody-like molecular recognition elements has been developed in recent years. Owing to its predetermination, specific recognition and practicability, furthermore, the molecular imprinting polymer(MIP) on basis of it with specific binding sites and excellent selectivity to the template, highly resistance towards various external degrading factors, remarkably stable and the high storage endurance , molecular imprinting technology has received much attention and extensively studie by many researchers during recent decades. The combination of MIT and QCM is greatly advantageous in broadening the application fields, reducing the price and prolonging the life of the sensor.In situ polymerization of chloramphenicol imprinting polymers on the surface of silver electrode of piezoelectric sensor is mainly discussed in this thesis. It is very covenient and high effective that a MIP biomimetic sensor is prepared by in situ technique.A piezoelectric sensor coated with an artificial biomimetic recognition element has been developed for the determination of chloramphenicol in the organic phase. The polymerization mixture consisted of chloramphenicol as the imprinted molecular , methacrylic acid 2-diethylaminoethyl ester as the functional monomer and ethylene glycol dimethacrylate as the cross-linker was cast in situ on to the surface of a silver-coated quartz crystal microbalance electrode as a thin permeable film, In the earlier work, the quantity of the cross-linker, the proportion of template and monomer and the reaction temperature are optimize-d. The results show the configuration of the functional monomer and the polarity of the porogenic solvent are very important in the forming of the selectivity to template. Selective rebinding of the target analyte was observed as a frequency shift quantified by piezoelectric microgravimetry with the QCM.The MIP sensor showed high selectivity and sensitivity to chloramphenicol. Alinear calibration response curve between 7.0 10-5mol/L~ 4.0 10-4mol/L was obtained.The detection limit was 3.0x10"5mol/L. The coating of the sensor was stable and can be reused for many times.The reproducibility of the sensor was excellent not only between runs but also between different coatings. It is envisaged that this technique could be employed to determine the concentration of residue chloramphenicol in the real life..In the late work, preparation of the molecularly imprinted microsphere in aqueous solution was studied. The results showed the MIP sensor can qualitative detection chloramphenicol in aqueous solution.