Electrochemical chemiluminescence responses on gold electrodes modified with ferrocenylundecanethiol monolayer and poly(divinylferrocene) film

Abstract

11-Ferrocenyl-1-undecanethiol (FcC11SH) self-assembled monolayer and poly(divinylferrocene) film (PDVF) on gold electrodes were used for the electrochemically-controllable catalysts for chemiluminescence of luminol. When the electrode potential became positive, ferrocene species of both monomolecular layer and polymer film on gold were oxidized to ferricinium cation species and then they catalyzed the chemiluminescence of luminol. In the case of FcC11SH monolayer, the number of surface attached ferrocene groups was two orders smaller than that in the case of the PDVF film estimated from the electrochemical measurements, although magnitudes of luminosities were similar. This result indicates that the FcC11SH monolayer modified gold electrode showed more efficient luminosity than that of polymer film modified gold electrode. Ferrocene groups on the FcC11SH/electrode surface can be re-oxidized to ferricinium cation species much easily. The catalytic reaction of chemiluminescence takes place only at the surface layer on the polymer film modified gold electrode.