New strategy for thermal sensitivity enhancement of Nd3+-based ratiometric luminescence thermometers

Accurate luminescence thermal sensing using nanophosphors that operate within biological windows is of great interest in bio- and nanomedicine. Here, we show that Nds-doped YVO4 NPs can act as nanothermometers in the second biological window upon 808 nm excitation. Significant enhancement of thermal sensitivity and temperature resolution was achieved by optimal choice of wavelengths for ratiometric thermal calibration. It was concluded that thermal calibration should be calculated using integral intensities. The obtained temperature uncertainty together with the emission and excitation lying in the biological windows open the venue to the possible application of Nds-doped YVO4 NPs for real time sub-tissue luminescence thermal sensing with a sub degree resolution.