Effects of fabrication parameters on the enzyme loading and sensor response of enzyme-carrying conductive polymer electrodes.

Hydrogen peroxide sensors where horseradish peroxidase (HRP) is incorporated into pyrrole/3-alkylsulfonate pyrrole copolymer films deposited on an SnO2 electrode (HRP/Py-PS electrode) were investigated with regard to the effects of the fabrication parameters (electropolymerization charge, deposition current density, and electrodeposition solution pH) on the amount of surface-immobilized enzyme and the sensor response. The amount of incorporated enzyme was determined with a method recently developed by ourselves. The results suggest that the amount of entrapped enzyme increases almost linearly with the total charge passed, and strongly depends on the polymer film growth rate and the electropolymerization pH. These findings open up a way to control the amount of enzyme and the resultant response of the biosensor by modifying the preparation conditions.