ULTRATHIN POROUS CARBON-FILMS AS AMPEROMETRIC TRANSDUCERS FOR BIOCATALYTIC SENSORS

Novel ultrathin (0.4 mu m) porous carbon films are employed as transdu cers for amperometric biosensors. Such foamlike nanoscopic films coupl e the advantages of high enzyme loadings (within the micropore hosts) and large microscopic area with a small geometric area. Both electropo lymerization and metalization are used to entrap the enzyme within the micropores. Scanning electron microscopy sheds useful insights into t he unique morphology of the growing enzyme layer. The greatly enhanced sensitivity is coupled with a fast and stable response. Factors influ encing the performance of porous-film-based biosensors are examined an d discussed. The improved performance is illustrated in connection wit h glucose and phenol sensors. The latter offers a remarkably low detec tion limit of 2.5 x 10(-8) M. The new nanoscopic foams should prove us eful for many other electroanalytical applications.