Cover Feature: Core or Shell? Er3+ FRET Donors in Upconversion Nanoparticles (Eur. J. Inorg. Chem. 44/2017)

The Cover Feature shows fluorescent dyes that are attached to three different upconversion nanoparticles (UCNPs) via DNA. Upon excitation with near‐infrared light, the green‐emitting UCNPs can transfer their energy to the dyes, which then emit orange photoluminescence. In the paper, the energy transfer from different core and core–shell UCNPs is investigated by time‐resolved spectroscopy for a better understanding of UCNP‐based Förster resonance energy transfer (FRET). More information can be found in the Full Paper by F. Vetrone, N. Hildebrandt et al.