DEVELOPMENT OF AMPEROMETRIC BIOSENSORS BASED ON THE IMMOBILIZATION OFENZYMES IN POLYMER-FILMS ELECTROGENERATED FROM A SERIES OF AMPHIPHILIC PYRROLE DERIVATIVES

A series of amphiphilic pyrrolyl-alkylammonium ions differing in the s ize of their ammonium heads has been used for the immobilization at th e electrode surface of horseradish peroxidase, galactose oxidase, poly phenol oxidase, glucose oxidase and xanthine oxidase in polypyrrolic f ilms electrogenerated from adsorbed amphiphilic pyrrole-enzyme mixture s. The enzyme retention properties of the different polymers have been determined indicating that the less hydrophobic monomer has the best immobilization efficiency. The electrochemical assays performed for ga lactose, glucose and hypoxanthine detection show clearly that the bioe lectrode sensitivity is related to the permeability of the host polyme r. The selectivity of the glucose oxidase electrodes towards interferi ng agents like ascorbate, urate and acetaminophen has also been examin ed, these agents interfering to some extent when present at physiologi cal concentrations.