SOL-GEL DERIVED, FERROCENYL-MODIFIED SILICATE-GRAPHITE COMPOSITE ELECTRODE - WIRING OF GLUCOSE-OXIDASE

A new type of porous, hybrid organic-inorganic material is synthesized and used for direct wiring of active enzymes. The material witnesses a dispersion of graphite powder and redox enzyme incorporated in a mul ti-functional, ferrocene-, amine- and methyl-modified silicate backbon e. Each species in this integrated construction accomplishes a special ized task: (a) the graphite provides conductivity by percolation; (b) the silicate provides the highly crosslinked, rigid backbone which is used to cage the redox enzyme; (c) ferrocene functional groups are res ponsible for the signal transduction from the active center of the enz yme to the electron conductive surface; (d) amine groups are incorpora ted for their high affinity for excess negative charges on the surface of glucose oxidase. Also, the combination of methyl and amine groups is advantageous to maintain control over the wetted electroactive sect ion of the electrode. Amperometric sensing of glucose demonstrates the application of this new material.