Two-Photon Excitation Temperature Nanosensors Based on a Conjugated Fluorescent Polymer Doped with a Europium Probe
- Publication Type
- Journal contribution (peer reviewed)
- Authors
- Wang, X.-D.;, Meier, R.J.; Schäferling, M.; Bange, S.; Lupton, J.M.; Sperber, M.; Wegener, J.; Ondrus, V.; Beifuss, U.; Henne, U.; Klein, C.; Wolfbeis, O.S.
- Year of publication
- 2016
- Published in
- Adv. Optical Mater.
- Band/Volume
- 4/
- DOI
- 10.1002/adom.201600601
- Page (from - to)
- 1854-1859
A strongly fluorescent organic semiconducting polymer doped with a highly temperature dependent fluorescent europium(III) complex is converted into a nanosized material that is capable of optically sensing temperature (T) in the range from 0 to 50 °C via two-photon excitation at 720 nm. The nanosensors are prepared from a blue-fluorescent polyfluorene that acts as both a light-harvesting antenna (to capture two-photon energy) and an energy donor in a fluorescence resonance energy transfer (FRET) system. The photonic energy absorbed by the polymer is transferred to the T-sensitive red-luminescent europium complex contained in the nanoparticles. The close spatial proximity of the donor and the acceptor warrants efficient FRET. A poly(ethylene glycol)-co-poly(propylene oxide) block copolymer is also added to render the particles biocompatible. It is shown that T can be calculated from a) the intensity of the luminescence of the europium complex, b) the ratio of the intensities of the red and blue luminescence, or c) the T-dependent luminescence lifetime of the Eu(III) complex