A new, extremely efficient method for the fabrication of films comprised of gold nanoparticles (GNPs) crosslinked by organic dithiols is presented in this paper. The method is based on layer-by-layer spin-coating of both components, GNPs and crosslinker, and enables the deposition of films several tens of nanometers in thickness within a few minutes. X-ray diffraction and conductance measurements reveal the proper adjustment concentration of the crosslinker solution of the critical is in order to prevent the destabilization and coalescence of particles. UV/vis spectroscopy, atomic force microscopy, and conductivity measurements indicate that films prepared via layer-by-layer spin-coating are of comparable quality to coatings prepared via laborious layer-by-layer self-assembly using immersion baths. Because spin-coated films are not bound chemically to the substrate, they can be lifted-off by alkaline underetching and transferred onto 3d-electrodes to produce electrically addressable, freely suspended films. Comparative measurements of the sheet resistances indicate that the transfer process does not compromise the film quality.

Networked films, comprising gold nanoparticles (ca. 4 nm core diameter) and 1,9‐nonanedithiol, are deposited onto oxidized low‐density polyethylene (LDPE) substrates via layer‐by‐layer self‐assembly. Scanning electron microscopy and transmission electron microscopy images reveal a compact coating with a granular, nanoscale morphology. Conductance measurements at variable temperature are consistent with an Arrhenius‐type activation of charge transport (activation energy: 52 meV). The excellent mechanical robustness of the coatings allows for studying their potential application as strain gauges. Expanding the films by up to 3% is accompanied by a reversible and approximately linear increase in resistance of up to approximately 50% (gauge factor ca. 17). Analyzing the results with an activated tunneling model suggests that the average increase in interparticle distances is significantly smaller than the geometric expansion at the substrate surface.

In this contribution a facile, one-step synthesis of tridentate thiol-functionalized PEO ligands and their ability to stabilize CdSe/CdS/ZnS core-shell-shell nanoparticles in aqueous media are described. The PEO-coated quantum dots show colloidal stability as well as preserved fluorescence even at very low concentrations of a few nM. For improved ligand attachment and enhanced fluorescence properties a method for ligand exchange was developed, which includes formation of a ligand zinc complex before the actual exchange reaction. The stability and fluorescence properties in various aqueous buffers and cell media and at pH values down to pH 3 were investigated. The firm binding of the tridentate ligands to the particle surface makes this ligand-particle system a promising tool for biological applications. In addition, activation of the ligands' terminal hydroxyl group for covalent biofunctionalization by esterification with succinic acid is reported.