The ionic permeation and discharge processes at a controllable-gate ion-channel electrode were investigated. The ionically transmissible films were formed on Au piezoelectrodes by surface modification performed using self-assembled monolayers (SAM) of glutathione (GS) molecules adsorbed onto gold. The gating state of a AuSG film was controlled by utilizing uncomplexed Cu2+ ions acting as the controller cations through their interactions with terminal carboxylic groups of AuSG, which results in a conformational transition leading to the film ion-channel opening. The open-gate conformation of AuSG is stabilized by lowering the solution pH. Under these conditions, we were able to record Cu2+ ion transport and discharge at a Au substrate surface accessible through the open ion gates. We have found that despite of a very limited space of this access, in the first stage of the Cu-0 deposition process, a Cu-upd on Au is formed, with LSV peak potential E-P = 0.385 V versus Ag/AgCl, though the rate of upd formation is lower than that for a upd on an unmodified Au, as evidenced by the decrease in the Cu deposited mass and the deposition charge. The value of the apparent charge transfer coefficient alpha(app) is also smaller (alpha(app) = 0.36 compared to 0.52 for bare Au). The 3D nucleation and growth of copper nanocrystals was observed using the potential step i-t and m-t transients. The size of Cu nuclei at the beginning of their overlapping process was in the range of d = 2-3 nm, which is larger than the ion-channel height (h approximate to 1.22 nm) determined for the open-gate conformation of AuSG. We found no dynamic film instabilities associated with fast potential step programs. (C) 2004 Elsevier Ltd. All rights reserved.