Ionic charge-selective electron transfer at fullerene-multilayered architecture on an indium-tin oxide surface

We report the first observation of the ionic charge-selective electron transfer at the fullerene-multilayered indium-tin oxide (ITO) electrode. The surface of the ITO electrode was modified by three layers of self-assembled fullerene/1,12-diaminododecane. The fullerene concentration in each layer was quantitatively measured by Rutherford backscattering spectrometry and UV spectrometry. Electron transfer was not observed from the electrode to the negatively charged Fe(CN)(6)(3-), but smooth electron transfer was made to the positively charged Ru(NH(3))(6)(3+) in an aqueous solution. At the extremely low concentration of Ru(NH(3))(6)(3+), 2 x 10(-6) M, the bare ITO could not detect the ruthenium complex, but the fullerene-multilayered electrode identified the presence of the cationic ruthenium complex, indicating the enrichment of the ruthenium cationic complex in the vicinity of the electrode.