Lanthanide doped nanoheaters with reliable and absolute temperature feedback

The development of selective and controlled photo-thermal therapies requires luminescent nanoparticles capable of simultaneous heating and contactless thermal sensing. Until now, thermal therapies have suffered from a lack of control over the absolute temperature of the treated tissue because the nanothermometers used for thermal feedback, based on a spectral analysis of emitted radiation, were affected by the inhomogeneous extinction of the tissues. This work shows how this deficiency can be overcome by using core-shell-shell nanostructures doped with lanthanide ions (Nd3+ and Yb3+). Thermal reading was achieved from the analysis of the Yb3+ luminescence lifetime whereas simultaneous heating was achieved thanks to the non-radiative deexcitations of Nd3+ ions. Simple proof-of-concept experiments show the great potential of these lanthanide-doped nanostructures for the development of in vivo photo-thermal treatments with absolute and reliable thermal feedback