Fabrication Of Chlortoluron And Oxytetracycline Sensors Based On Molecular Imprinted Films

In part one, two electrochemical sensors were propsed by electro-synthesized and chemical polymerization in aqueous based on the recognition function of molecular imprinted film.(1) Molecularly imprinted polymer (MIP) was prepared by a reaction among template molecules of chlortoluron, functional monomers of methacrylic acid, and a crosslinker of N,N'- methylenebisacrylamide on platinum electrode in acid solution. While potassium ferricyanide was worked as the probe, cyclic voltammograms (CV), Infrared spectroscopy (IR) and AC impedance spectroscopy (AC) were performed to characterize and study the molecular imprinted film. Differential pulse voltammograms (DPV) was carried out to build a method for chlortoluron detection. Chlortoluron could be analyzed in the range of 0 to 3×10-6 mol/L with a detection limit of 2.21×10-8 mol/L. Water samples were assayed and recoveries were obtained, ranging from 99% to 102%. (Chapter 2)(2) Molecularly imprinted films (MIP) were prepared for the determination of chlortoluron by electropolymerization method on gold electrode, and it's imprinting effect, performance and compared with the selective response of similar material of chlortoluron were studied in this work. Differential pulse voltammograms(DPV) was carried out to build a method for chlortoluron detection. Chlortoluron could be analyzed in the range of 3×10-7 to 1.5×10-6 mol/L with a detection limit of 1.0×10 -7 mol/L mol/L. Water samples were assayed and recoveries were obtained, ranging from 99.0 % to 107.3 %.(Chapter 3)In part two, oxytetracycline molecularly imprinted sensors were propsed by electro-synthesized based on the recognition function of molecular imprinted film. Two method for trace oxytetracycline detection were established based on enzyme amplifiers.(3) A novel strategy for preparing highly sensitive molecularly imprinted sensors based on enzyme amplifiers was proposed for oxytetracycline (OTC) determination. A molecularly imprinted film was used as an artificial antibody to interact with OTC and horseradish peroxidase labeled OTC (abbr. HRP-OTC). Afterwards, OTC was determined according to the competition reaction. The molecular imprinted sensor was characterized by Fourier transform infrared spectroscopy (IR), alternating current (AC) impedance spectroscopy, differential pulse voltammetry (DPV), and cyclic voltammetry (CV). The DPV technique was performed to verify the voltammetric behavior of the molecular imprinted immunosensor. At concentrations of 0 ¹.0×10^-7 mol/L, OTC could be determined with a detection limit of 6.49×10^-10 mol/L. The MIP immunosensor showed high sensitivity, selectivity, and reproducibility. Milk samples were assayed and recoveries were obtained, ranging from 98.2 % to 101.5 %. (Chapter 4)(4) A novel strategy for preparing highly sensitive molecularly imprinted sensors based on enzyme amplifiers was proposed for oxytetracycline (OTC) determination. A molecularly imprinted film was used as an artificial antibody to interact with OTC and glucose oxidase labeled OTC (abbr. GOD-OTC). Afterwards, OTC was determined according to the competition reaction. The molecular imprinted sensor was characterized by Fourier transform infrared spectroscopy (IR), alternating current (AC) impedance spectroscopy, differential pulse voltammetry (DPV), and cyclic voltammetry (CV). The DPV technique was performed to verify the voltammetric behavior of the molecular imprinted immunosensor. At concentrations of 0 3.6×10^-7 mol/L mol/L, OTC could be determined with a detection limit of 4.30×10¹⁰ mol/L. The MIP immunosensor showed high sensitivity, selectivity, and reproducibility. Milk samples were assayed and recoveries were obtained, ranging from 98.8 % to 103.3 %. (Chapter 5)...