Electrochemical impedance spectroscopy studies of polymer degradation: application to biosensor development

Electrochemical impedance spectroscopy (EIS) has emerged as a useful analytical tool for the development of sensor devices in a wide variety of configurations. We focus this review on the particular application of EIS to the study of degradation phenomena taking place at polymer-coated substrates, which have primarily been of great interest in the study of corrosion protection; more recently, it has led to the successful construction of versatile polymer-coated transducers for sensor development. Impedance analysis of breakdown processes of polymer coatings on electrochemical transducers through the direct or indirect action of biomolecules constitutes a feasible detection protocol for the fabrication of generic integrated biosensors. We give a detailed description of such applications, and present a particular view on sensor devices reported so far and ideas that bring significant improvements to this promising technology. (C) 2004 Elsevier Ltd. All rights reserved.