molecularly imorinted electrochemical sensor to enantroselecctively recogenize D and L-tyrosine

• Main Authors: Hui-jing Liang, 梁慧靜
• Other Authors: Tzong-Rong Ling
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/21161894099878154360

碩士 === 義守大學 === 生物技術與化學工程研究所碩士班 === 93 === Electrochemical sensors were fabricated on nickel and platinum electrodes by molecularly imprinting D and L tyrosine on polypyrrole films to form complementary cavities for subsequent template recognition. The performance of the imprinted films was evaluated by coulometry using an applied positive potential to induce adsorption of the target molecules. Using this procedure high enantioselectivities were found for each imprinted film. In this study, the most individual selectivities for L and D tyrosine on their respective imprinted films were estimated to be L/D=9.4/1 and D/L=27.2/1, determined by applying potential at a sweep rate of 0.1V/s from -0.1 to 0.5V (vs. Ag/AgCl) with the two enantiomers being present at the same concentration(5mM). Several factors affecting rebinding, such as: extraction time, film thickness, template concentration and sweep rate were investigated to achieve optimum recognition ability. The diffusion of target molecules in the polypyrrole films was also examined. Both thermal polymerization and eletropolymerization methods can be used to prepare a tyrosine imprinted film with high selectivity. A closed pack structure of tyrosine imprinted polyprrole film is obtained by eletropolymerization with CV, but NaOH treatment is needed to activate the rebinding of the film. A recognition mechanism for the interaction of the polypyrrole film for its template under the influence of an applied positive potential is proposed in this study.