THE EFFECTS OF CHAIN-LENGTH OF FERROCENE MOIETY ON ELECTRICAL COMMUNICATION OF MEDIATORS-MODIFIED AND ENZYMES-MODIFIED ELECTRODES

Electrical communication between alcohol dehydrogenase and graphite electrode is established in a domain of poly(acrylic acid) thin layer coated on graphite felt in which ferrocene, NADH, diaphorase and alcohol dehydrogenase are chemically immobilized. It was confirmed that NADH was not directly oxidized with ferrocene derivatives and needed the intervention of diaphorase between ferrocene derivatives and NADH. The effects of ferrocene derivatives with different alkyl chain lengths (Fc-CH2NH(CH2)nNH2, n=4 approximately 12) to electromediatory oxidations of NADH and alcohol dehydrogenase were examined and the best result was obtained by the use of the flexible ferrocene derivatives with spacer lenghth of 12 approximately 15 angstrom (n=6 approximately 8).