SOL-GEL-DERIVED COLD COMPOSITE ELECTRODES

The preparation, characterization, and analytical utility of sol-gel-d erived gold composite electrodes is described. The new metal-ceramic e lectrodes are comprised of gold powder homogeneously dispersed in a mo dified silica matrix They couple the favorable electron-transfer kinet ics common to gold surfaces with the regeneration, bulk modification, and versatility features of sol-gel-derived composite materials. The v oltammetric characteristics of the Composite gold-silica electrodes ar e explored and compared with conventional gold electrodes. Sol-gel-der ived gold biosensors have been prepared by incorporating an oxidase en zyme within the sol-gel gold solution. Analogous thick-film enzyme str ips, based on a new screen-printable gold biogel ink, have also been f abricated. To our knowledge, the above represent the first examples of metal-ceramic sensing electrodes and of bulk modification of metallic working electrodes.