Plasmonic nanoparticles with spectral properties in the UV‐to‐near‐IR range have a large potential for the development of innovative optical devices. Similarly, microstructured optical fibers (MOFs) represent a promising platform technology for fully integrated, next‐generation plasmonic devices; therefore, the combination of MOFs and plasmonic nanoparticles would open the way for novel applications, especially in sensing applications. In this Full Paper, a cost‐effective, innovative nanoparticle layer deposition (NLD) technique is demonstrated for the preparation of well‐defined plasmonic layers of selected particles inside the channels of MOFs. This dynamic chemical deposition method utilizes a combination of microfluidics and self‐assembled monolayer (SAM) techniques, leading to a longitudinal homogeneous particle density as long as several meters. By using particles with predefined plasmonic properties, such as the resonance wavelength, fibers with particle‐adequate spectral characteristics can be prepared. The application of such fibers for refractive‐index sensing yields a sensitivity of about 78 nm per refractive index unit (RIU). These novel, plasmonically tuned optical fibers with freely selected, application‐tailored optical properties present extensive possibilities for applications in localized surface plasmon resonance (LSPR) sensing.

Certain metal nanoparticles exhibit the effect of localized surface plasmon resonance when interacting with light, based on collective oscillations of their conduction electrons. The interaction of this effect with molecules is of great interest for a variety of research disciplines, both in optics and in the life sciences. This paper attempts to describe and structure this emerging field of molecular plasmonics, situated between the molecular world and plasmonic effects in metal nanostructures, and demonstrates the potential of these developments for a variety of applications.

Due to their beneficial properties, the use of zinc oxide nanoparticles (ZnO NP) is constantly increasing, especially in consumer-related areas, such as food packaging and food additives, which is leading to an increased oral uptake of ZnO NP. Consequently, the aim of our study was to investigate the cellular uptake of two differently sized ZnO NP (<50 nm and <100 nm; 12–1229 µmol/L) using two human intestinal cell lines (Caco-2 and LT97) and to examine the possible resulting toxic effects. ZnO NP (<50 nm and <100 nm) were internalized by both cell lines and led to intracellular changes. Both ZnO NP caused time- and dose-dependent cytotoxic effects, especially at concentrations of 614 µmol/L and 1229 µmol/L, which was associated with an increased rate of apoptotic and dead cells. ZnO NP < 100 nm altered the cell cycle of LT97 cells but not that of Caco-2 cells. ZnO NP < 50 nm led to the formation of micronuclei in LT97 cells. The Ames test revealed no mutagenicity for both ZnO NP. Our results indicate the potential toxicity of ZnO NP after oral exposure, which should be considered before application.