Abstract: This paper is concerned with the mechanism of intrazeolite electron transfer in zeolite modified electrodes(ZMEs) where the zeolite have been modified with polyaniline. First, data were obtained from ZMEs prepared with zeolite Yloading aniline and the electropolymerizing of anilines was performed by cyclic voltammery. Polyaniline might not leak out from zeolite due to the bulk size of polyaniline being bigger than the channel of zeolite Y. At the absence of electron transfer mediators, the Pan +Y ZME showed the expected presence of electron hopping of adjacent polyaniline cations. Second, the data were obtained for the determining Cd ²⁺and ascorbic acid using Pan⁺Y-ZME. The Cd²⁺might not be preconcentrated at open circuit and could be done at constant potential. At the absence of ion exchange between zeolite and surrounding electrolyte the electron transfer was performed via the electron hopping, i.e . by an intrazeolite mechanism; rather than by an extrazeolite mechanism. In addition, the ascorbic acid molecule and its anion could not cross zeolite film to base electrode therefore, its current was conducted also by the electron hopping between the chains of polyaniline. Experimental results indicate that the electron transfer of Pan⁺Y-ZME was dominated by intrazeolite processes.

Key words: Zeolite modified electrode, Polyaniline, Intrazeolite electron transfer