Modification of glucose oxidase by the covalent attachment of a tetrathiafulvalene derivative

摘要: 4-[(3'-Carbohydroxypropyl)thio]-5-(methylthio)tetrathiafulvalene was synthesized and used as a mediator for the oxidation of glucose oxidase both free in solution after covalent attachment to enzyme through carbodiimide coupling amine residues protein, The modified characterized by isoelectric focusing gel electrophoresis found have higher pi than native enzyme, Electrochemical studies show that singly oxidized tetrathiafulvalene derivative attached can act direct reoxidation at electrode surfaces, whereas doubly dication is not mediator. Similar results are mediation solution, application membrane electrodes investigated, response were analyzed give kinetic information about kinetics, Our has good stability on storage absence but less stable during continuous operation sensor, This appears arise from reactions between tetrathiafulvanene groups traces hydrogen peroxide generated enzymatic reaction with oxygen present solution.