Transport through the nuclear pore complex (NPC) involves a large channel and an abundance of binding sites for nuclear transport receptors (NTRs). However, the mechanistically important distribution of NTRbinding sites along the channel is vividly debated. In this study, we visualized binding site distributions directly by two complementary optical super-resolution methods, single-molecule microscopy and 4Pi microscopy. First, we analyzed the distribution of RanGDP because this important nuclear transport substrate has two types of binding sites at the NPC, direct and indirect, NTRmediated sites. We found that the direct binding sites had a maximum at approximately −30 nm with regard to the NPC center, whereas the indirect transport-relevant binding sites peaked at approximately −10 nm. The 20 nm-shift could be only resolved by 4Pi microscopy because of a two to threefold improved localization precision as compared with single-molecule microscopy. Then we analyzed the distribution of the NTR Kapβ1 and a Kapβ1-based transport complex and found them to have also binding maxima at approximately −10 nm. These observations support transport models in which NTR binding sites are distributed all along the transport channel and argue against models in which the cytoplasmic entrance of the channel is surrounded by a large cloud of binding sites.

A new process is presented that combines nanoimprint lithography and soft lithography to assemble metal–bridge–metal crossbar junctions at ambient conditions. High density top and bottom metal electrodes with half‐pitches down to 50 nm are fabricated in a parallel process by means of ultraviolet nanoimprint lithography. The top electrodes are realized on top of a sacrificial layer and are embedded in a polymer matrix. The lifting of the top electrodes by dissolving the sacrificial layer in an aqueous solution results in printable electrode stamps. Crossbar arrays are noninvasively assembled with high yield by printing the top electrode stamps onto bare or modified bottom electrodes. A semiconducting and a quasi metal like conducting type of polymer are incorporated in the cross points to form metal‐polymer‐metal junctions. The electrical characterization of the printed junctions revealed that the functional integrity of the electrically addressed conductive polymers is conserved during the assembling process. These findings suggest that printing of electrodes represents an easy and cost effective route to highly integrated nanoscale metal‐bridge‐metal junctions if imprint lithography is used for electrode fabrication.

Low impedance electrodes are of significant importance for the development of highly sensitive sensors and bioelectronic devices. The integration of biomolecules into these devices enforces high demands on the interface materials in terms of biocompatibility and electronic properties. Here we present the establishment of the well studied conductive polymer (CP) PEDOT/PSS for ultra thin electrode coatings. The polymer film thickness is adjusted via spin coating and reaches film thicknesses well below 100 nm. Thereby, the polymer layer increases the interface capacity and allows a tuning of the electrode impedance. A further reduction of the impedance is achieved by applying CP coatings on gold nanopillar electrode surfaces.Schematic of polymer coated gold nanopillars electrode in a cyclic voltammetry experiment.

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