39076 2017 eng lecture 0 -- -- -- Lanthanide-doped up-converting nanoparticles (UCNPs) are promising reporters for medical diagnostics and bioimaging. Current limitations present their relative low absorption cross sections and low fluorescence efficiencies, with the latter being affected by particle size, surface chemistry, and microenvironment, particularly water. Here, we present results from systematic studies of the excitation power density dependent upconversion luminescence spectra, intensities/intensity ratios of the individual emission bands, slope factors, and quantum yields of UCNPs of varying size, dopant concentration, and surface chemistry in different microenvironments as well as the up- and downconversion luminescence decay kinetics of the different emission bands. Moreover, first studies of the energy transfer from UCNPs to surface-bound organic dyes acting as fluorescence acceptors are shown. Based upon these measurements, fluorescence deactivation channels are identified and spectroscopic parameters for the screening of material performance are derived. Projekttreffen COST Straßbourg, France 09.01.2017 09.01.2017 0 Ute Resch-Genger eng uncontrolled Upconverting nanoparticles eng uncontrolled Size eng uncontrolled FRET eng uncontrolled Fluorescence eng uncontrolled Absolute fluorescence quantum yield eng uncontrolled Fluorescence decay kinetics eng uncontrolled Power density dependence Ingenieurwissenschaften und zugeordnete Tätigkeiten Datei im Netzwerk der BAM verfügbar ("Closed Access") Präsentation