Preparation And Application Of Molecularly Imprinted Electrochemical Sensor Doped Silane Polymer

Molecularly imprinted polymers (MIPs) have a lot of advantages, such as high sensitivity and selectivity, simple, long service life, and so on. For this reason, MIPs are widely used for separation, biosensing and extraction. The use of biosensors has difficulties in preservation, limited object. The MIPs sensors conquer the above drawbacks, and become one of the research hotspots in electrochemical sensor. Since the development of sol-gel technology, there has been increasing interest in use of imprinted polymers as thin films for electrochemical sensor devices. Comparing with other techniques, the advantage of sol-gel is that the thickness and the surface area of the film can be regulated and monitored easily. In this paper, the imprinted sol-gel film was prepared by using silane as a functional monomer, β-agonists as a template and columnar Pt electrode as a substrate electrode. The imprinted electrochemical sensors have the advantages of high sensitivity and recognition ability. Therefore, the sensors were satisfactorily applied to determine β-agonists in real samples.The main contents of this thesis are summarized as follow:(1) A novel electrochemical sensor for β-agonists with high sensitivity and selectivity based on surface molecularly imprinted sol-gel doped with antimony-doped tin oxide.The imprinted sol-gel film was prepared by mixing silica sol with a functional monomer of antimony-doped tin oxide (ATO), a template of β-agonists. Chitosan (CS) and columnar Pt electrode were used as an adhesive and a substrate electrode, respectively. The imprinted sensor was characterized by field emission scanning electron microscope (FE-SEM), laser scanning microscope (LSM), fourier transform infrared spectroscopy (FT-IR) and electrochemical methods. The conditions, including elution time, incubation time, etc., were optimised. Under the optimal experimental conditions, the proposed sensor exhibit a wide linear range and low detection limit for β-agonists. Meanwhile, the electrochemical sensor showed excellent specific recognition of the template molecule among structurally similar coexisting substances. Furthermore, the imprinted sensor was satisfactorily applied to determine β-agonists in human serum samples. The good results indicated that highly effective molecularly imprinted sol-gel films doped with ATO can be employed for other analytes.(2) Fabrication and analytical application of imprinted sol-gel sensor for β-agonists based on and molecularly imprinted/β-agonists/Fe3+-sol-gel/CS modified columnar Pt electrode.The imprinted sol-gel film was prepared by mixing dodecyltrimethoxysilane with a functional monomer of Fe3+, a template of β-agonists and a crosslinker of (3-glycidoxypropyl)methyldiethoxysilane. CS and columnar Pt electrode were used as an adhesive and a substrate electrode, respectively. The imprinted sensor was characterized by fourier transform infrared spectroscopy (FT-IR) and electrochemical methods. The experimental conditions, including elution time, incubation time, etc., were optimized. Under the optimal experimental conditions, the imprinted sensor exhibit a wide linear range and low detection limit for β-agonists. The optimized sensors were successfully applied to determine β-agonists in human serum samples.