New strategies for luminescence thermometry in the biological range using upconverting nanoparticles

We have studied different strategies of use of luminescence thermometry with upconverting nanoparticles in the biological range of temperatures, among them, the thermal sensing ability of fluoresncent lifetime of Er,Yb:NaY 2 F 5 nanoparticles. Er,Yb:NaY 2 F 5 O nanocrystals show great potentiality as thermal sensors at the nanoscale for biomedical applications due to the incorporation of additional non-radiative relaxation mechanisms that shorten the emission lifetime generated by the oxygen present in the structure. Here we report ex-vivo temperature determination by laser induced heating in chicken breast using lifetime-based thermometry in these up-conversion nanoparticles.