We report voltage-clamp measurements through single conical nanopore obtained by chemical etching of a single ion track in polyimide film. Special attention is paid to the pink noise of the ionic current (i.e., 1/f noise) measured with different filling liquids. The relative pink-noise amplitude is almost independent of concentration and pH for KCl solutions, but varies strongly using ionic liquids. In particular, we show that depending on the ionic liquid, the transport of charge carriers is strongly facilitated (low noise and higher conductivity than in the bulk) or jammed. These results show that the origin of the pink noise can be ascribed neither to fluctuations of the pore geometry nor to the pore wall charges, but rather to a cooperative effect on ions motion in confined geometry.

International audienceSelf-assembled monolayers of 1,4-diisocyanobenzene on gold were used to bind ruthenium phthalocyanines to the surface by axial ligation of the macrocycle with isocyanide groups pointing out from the SAM. The 1,4-diisocyanobenzene SAM and the RuPc-1,4-diisocyanobenzene bilayer were characterized by ellipsometry, IRRAS, XPS, and SPM. The grafting of RuPc to the SAM is stable. The thickness of the film increases from 10 to 15 Å upon RuPc ligation. IRRAS reveals that both ends of the 1,4-diisocyanobenzene are affected by the NC to metal interaction occurring at the other end. XPS indicates that each RuPc macrocycle covers ~12 1,4-diisocyanobenzene molecules in the bilayer