Electrogeneration of a hydrophilic cross-linked polypyrrole film for enzyme electrode fabrication. Application to the amperometric detection of glucose

A new dipyrrolic derivative linked with a long hydrophilic spacer has been synthesized. The electrooxidation of this monomer in water either in its solubilized or adsorbed state, leads to the formation of a polymer film on the electrode surface. Consequently, the two procedures of electropolymerization allow one to modulate the conditions of enzyme immobilization depending on the geometry and size of the electrode. Thus, these procedures have been applied to the immobilization of glucose oxidase as on enzyme model. The amperometric response of the resulting biosensors to glucose has been studied at 0.6 V(vs. SCE;), through the oxidation of the generated H2O2. The influence of different parameters such as enzyme and monomer concentrations, amount of enzyme and monomer preadsorbed and polymerization procedure, on the biosensor performance has been examined. The glucose sensitivity of the optimized configuration of enzyme electrode was 3.93 mA M(-1)cm(-2).