A laponite clay-poly(pyrrole-pyridinium) matrix for the fabrication of conductimetric microbiosensors

The functionalization of an interdigitated microelectrode array by a compos ite matrix containing urease molecules and its application to the conductim etric detection of urea is described. Urease was entrapped in laponite clay gel and cross-linked by glutaraldehyde. The latter coating was adsorbed on to an electrochemically generated poly(pyrrole-pyridinium) film. The compar ison of different organic and inorganic host matrices in terms of storage a nd operational stabilities clearly demonstrated the advantages of the compo site matrix. Finally, in order to illustrate the potentialities of the comp osite matrix for the fabrication of conductimetric microbiosensors, the imm obilization of glucose oxidase on microelectrode arrays and the conductimet ric detection of glucose were successfully performed. (C) 1999 Elsevier Sci ence B. V. All rights reserved.