Two types of gold nanoclusters (GNCs), one covered by self-assembled monolayers of mercaptoundecanoic acid (MUA), hexanethiol (C6SH), and ferrocenylhexanethiol (FcC(6)SH), MHF-GNC, and the other with MUA and C6SH, MH-GNC, were used for the construction of ten GNC layers of two different sequences on an MUA modified Au(I 1 1) surface based on the carboxylate/polycation (poly(allylamine hydrochloride), PAH)/carboxylate electrostatic interaction. MHF-GNC was placed either as the layer closest to the gold electrode, i.e. the first layer, or as the outermost layer with MH-GHC in the other layers. A quasi-reversible redox peak with a constant charge corresponding to the redox reaction of the ferrocene moiety of the MHF-GNC monolayer was observed at both electrodes, showing electrons and perchlorate ions could be transferred through the MH-GNC/PAH multilayers. Cross-sectional transmission electron microscopy (TEM) revealed that the size of the immobilized GNC was almost same as that in solution and well-separated GNCs were dispersed rather uniformly within the polymeric matrix. The incorporation of perchlorate ion upon the oxidation of the ferrocene moiety of the MHF-GNC was demonstrated by electrochemical quartz crystal microbalance measurement. Based on the above results, the charge transfer mechanism in the GNC multilayers was discussed. (C) 2003 Elsevier B.V. All rights reserved.