In search of suitable matrices for enzyme immobilization, there has been a growing interest in
attaching the enzymes to the solid electrolyte Nafion. The Nafion membrane possesses a high surface adhesion property and a low swelling capability in aqueous media. Being a negatively
charged polyelectrolyte matrix, Nafion exhibits a
reduced permeability to negatively charged substances, therefore improving the sensor selectivity and virtually eliminating the interference of
reductants such as ascorbate and acetaminophen.
On the other hand, a Nafion film possesses a high
ability to entrap positively charged redox-active
compounds that can be used as mediators in bioelectro catalytic reactions. In addition, the polyelectrolyte nature of the Nafion film can stabilize
the ionic strength at the electrode surface,
thereby preventing electrode fouling and increasing the dynamic range for analyte detection.