TY - JOUR A1 - Wang, X.-d. A1 - Meier, R.J. A1 - Schäferling, Michael A1 - Bange, S. A1 - Lupton, J.M. A1 - Sperber, M. A1 - Wegener, J. A1 - Ondrus, V. A1 - Beifuss, U. A1 - Henne, U. A1 - Klein, C. A1 - Wolfbeis, Otto S. T1 - Two-photon excitation temperature nanosensors based on a conjugated fluorescent polymer doped with an Europium probe N2 - 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 lightharvesting 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. KW - Optical sensor KW - Temperature sensor KW - Nanosensor KW - FRET system PY - 2016 UR - http://onlinelibrary.wiley.com/doi/10.1002/adom.201600601/abstract U6 - https://doi.org/10.1002/adom.201600601 SN - 2195-1071 VL - 4 IS - 11 SP - 1854 EP - 1859 PB - Wiley-VCH CY - Weinheim AN - OPUS4-38737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -