Development of Amperometric Biosensor Based on Tyrosinase Immobilized in Phosphate-Doped Polypyrrole Film for Detection of Biogenic Amines

摘要

An electrochemical tyrosinase electrode for detection of tyramine and dopamine was developed via cross-linking immobilization method in phosphate-doped polypyrrole film. The enzyme tyrosinase preserves its biocatalytic activity well within the polypyrrole thin film. Tyramine and dopamine were determined by the direct reduction of biocatalytically formed dopaquinone species at -0.250V. The analytical characteristics of this biosensor, including linear range, detection limit, and storage stability are described. For both biogenic amines analyzed, the kinetics of the enzymatic reaction fitted into a Michaelis-Menten type kinetics. The sensitivity followed the decreasing order dopamine > tyramine. The greater value of maximum velocity rate and the lowest Michaelis-Menten constant was found for dopamine.