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

The functionalization of an interdigitated microelectrode array by a composite matrix containing urease molecules and its application to the conductimetric detection of urea is described. Urease was entrapped in laponite clay gel and cross-linked by glutaraldehyde. The latter coating was adsorbed onto an electrochemically generated poly(pyrrole–pyridinium) film. The comparison of different organic and inorganic host matrices in terms of storage and operational stabilities clearly demonstrated the advantages of the composite matrix. Finally, in order to illustrate the potentialities of the composite matrix for the fabrication of conductimetric microbiosensors, the immobilization of glucose oxidase on microelectrode arrays and the conductimetric detection of glucose were successfully performed.