Study On Piezoelectricity Biosensor And Its Application For The Determination Of Some Pesticides & Veterinary Drugs Based On Molecularly Imprinted Polymers As Recognition Element

Molecularly Imprinted Polymers(MIPs) is a kind of high polymer based on the antigen-immune body reaction principal, and synthesis by chemistry method, which is also called "the artificial immune body". The molecular imprinted polymers has the ability that selective the target from many kinds of components. Because that the chemical properties of molecular imprinted polymers are stable, at present, molecular imprinted polymers are already widely applied in sample separation, solid phase extract and biological sensor examination.Traditional preparation method of Molecularly imprinted polymer is corpus polymerization, which needs to undergo the attrition and screening, so the preparation process is complex, moreover the obtained grain shape is anomalous, and the recognition efficiency is low. And because uses aerosol, the emulsion polymerization obtained polymer microballoons to include the surface active agent, the post-processing working procedure is complex, and has certain influence to the signature polymer's adsorption performance, thus has limited its application domain. There are many advantage of precipitates polymerization, for example, the equipment is simple, the signature particle size is homogeneous, specific surface area is bigger than the one by tranditional method, which is high-performance in the signature adsorption.By piezoelectric biosensor is a biological signal into an electrical signal to the output of the sensor with high sensitivity, fast response, simple operation.The more commonly used piezoelectric quartz microbalance sensor (QCM), surface quality through the electrode to changes in the vibration frequency of quartz changes the frequency by changing the amount of software that records the output, measured by this method to achieve the purpose of small change in the quality.Load to the electrode surface antibodies, enzymes and bio-active material, can be used for pesticide and veterinary drug residues in food detection.But the antibody and the enzyme preparation cycle length, and poor resistance to extreme environmental drawbacks, artificial antibodies-molecular imprinted polymer antibodies and enzymes can be an alternative material as sensor, and components.In this study, Carbofuran, Parathion, Ractopamine and Chloramphenicol are as the research object, synthesis of molecular imprinted polymers, and to explore building a piezoelectric quartz microbalance sensor (QCM) method. Computer software (HyperChem 8.0), UV spectra are used to character the action mechanism of template molecule and functional in order to predict the feasibility of molecular imprinted polymers. In the experiment, we add different amount of initiator to observe the polymer properties. The physical properties of the polymer using environmental scanning electron microscope analysis showed that the synthesis of micro-ball shape of rules, uniform particle size, particle size is about 300nm.Equilibrium adsorption and mathematical model are used to deduce the maximum adsorption capacity of imprinted polymer (Qmax) and the equilibrium dissociation constant (KD).Scatchard analysis is used to analysis the imprinted materials binding site.Use the template molecule analogues on molecularly imprinted polymers selective adsorption analysis showed that there is a high specificity of molecular adsorption. The data shows that the method of molecular imprinted polymer synthesized meets the requirements, and may be used in pesticide and veterinary drug enrichment.Based on the work of this study, we have also make parathion and chloramphenicol molecularly imprinted polymer be fixed on the quartz crystal microbalance.The PVC and tetrahydrofuran (THF) were as the embedding material and solvent. Detect conditions, such as coating weight and the background solution were estimated to optimize the composition and experimentation. We carried out a preliminary application of experiments obtained detector of chloramphenicol residues in shrimp and liver,and the data were compared with traditionary detection method, which certified that the MIP-QCM method is a sensitive method in pesticide and veterinary drug detection, and faster, cheaper than ELISA and chromatograph.This study gives us some helpful method and theory in real-time, on-spot, fast detection of pesticides and veterinary drugs residue in foodstuff.