The improved potentiometric pH response of electrodes modified with processible polyaniline. Application to glucose biosensor

Abstract

Processible polyaniline (PCPAn) modified electrodes are characterized by an advanced potentiometric pH response in comparison to those based on regular polyaniline. Glassy carbon electrodes modified with PCPAn by dip-coating exhibited a fully reversible potentiometric response of approximately 90 mV pH^–1 over the range pH 3–9. Such significantly higher potentiometric responses of PCPAn modified electrodes compared to existing devices is explained on the basis of the thermodynamics of polyaniline redox reactions. The potentiometric biosensor for glucose based on processible polyaniline has been developed using a non-aqueous enzymology approach for enzyme immobilization. In the model solution, which mimics blood serum, the biosensor was useful for glucose detection over the concentration range 0.1–30 mM and the maximum response value reached was ≈80 mV. The advanced potentiometric response of PCPAn modified electrodes provides their application for sensor and biosensor development.