TY  - JOUR
A1  - López de Guereñu, Anna
A1  - Bastian, Philipp
A1  - Wessig, Pablo
A1  - John, Leonard
A1  - Kumke, Michael Uwe
T1  - Energy Transfer between Tm-Doped Upconverting Nanoparticles and a Small Organic Dye with Large Stokes Shift
JF  - Biosensors : open access journal
N2  - Lanthanide-doped upconverting nanoparticles (UCNP) are being extensively studied for bioapplications due to their unique photoluminescence properties and low toxicity. Interest in RET applications involving UCNP is also increasing, but due to factors such as large sizes, ion emission distributions within the particles, and complicated energy transfer processes within the UCNP, there are still many questions to be answered. In this study, four types of core and core-shell NaYF4-based UCNP co-doped with Yb3+ and Tm3+ as sensitizer and activator, respectively, were investigated as donors for the Methyl 5-(8-decanoylbenzo[1,2-d:4,5-d ']bis([1,3]dioxole)-4-yl)-5-oxopentanoate (DBD-6) dye. The possibility of resonance energy transfer (RET) between UCNP and the DBD-6 attached to their surface was demonstrated based on the comparison of luminescence intensities, band ratios, and decay kinetics. The architecture of UCNP influenced both the luminescence properties and the energy transfer to the dye: UCNP with an inert shell were the brightest, but their RET efficiency was the lowest (17%). Nanoparticles with Tm3+ only in the shell have revealed the highest RET efficiencies (up to 51%) despite the compromised luminescence due to surface quenching.
KW  - resonance energy transfer
KW  - DBD dye
KW  - core shell UCNP
KW  - time-resolved luminescence
Y1  - 2019
U6  - https://doi.org/10.3390/bios9010009
SN  - 2079-6374
VL  - 9
IS  - 1
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Inal, Sahika
A1  - Koelsch, Jonas D.
A1  - Chiappisi, Leonardo
A1  - Kraft, Mario
A1  - Gutacker, Andrea
A1  - Janietz, Dietmar
A1  - Scherf, Ullrich
A1  - Gradzielski, Michael
A1  - Laschewsky, André
A1  - Neher, Dieter
T1  - Temperature-Regulated Fluorescence Characteristics of Supramolecular
 Assemblies Formed By a Smart Polymer and a Conjugated Polyelectrolyte
JF  - MACROMOLECULAR CHEMISTRY AND PHYSICS
N2  - Aqueous mixtures of a coumarin-labeled non-ionic thermoresponsive copolymer and a cationic polythiophene exhibit marked changes in their fluorescence properties upon heating. At room temperature, emission from the label is significantly quenched due to energy transfer to the conjugated polyelectrolyte. Heating the mixture reduces the energy-transfer efficiency markedly, resulting in a clearly visible change of the emission color. Although the two macromolecules associate strongly at room temperature, the number of interacting sites is largely reduced upon the phase transition. Crucially, the intermolecular association does not suppress the responsiveness of the smart polymer, meaning that this concept should be applicable to chemo- or bioresponsive polymers with optical read-out, for example, as a sensor device.
KW  - aqueous solutions
KW  - conjugated polyelectrolytes
KW  - fluorescence (or Forster)
KW  - resonance energy transfer
KW  - phase transitions
KW  - thermoresponsive polymers
Y1  - 2013
U6  - https://doi.org/10.1002/macp.201200493
SN  - 1022-1352
VL  - 214
IS  - 4
SP  - 435
EP  - 445
PB  - WILEY-V C H VERLAG GMBH
CY  - WEINHEIM
ER  -