Electrochemical characterization of polypyrrole glucose oxidase biosensor .1. Influence of enzyme concentration on the growth and properties of the film

We describe the effect of enzyme on the electrochemical polymerization of pyrrole and on the permeability of the resulting polypyrrole/glucose oxidase (PPy/GOD) film by using electrochemical methods. The growth rate of the film decreased with increasing enzyme concentration in the electrodeposition solution. Scanning electron microscopic observations also revealed that the morphology of the resulting film markedly changed in the presence of enzyme and that surface roughness deceased with increasing enzyme concentration. The responses of the resulting PPy/GOD biosensor to glucose and ascorbate were characterized to examine the permeability of the films. Our results suggest that the permeability of the resulting film has a negative dependence on the enzyme concentration in the deposition solution.