Robust emission in near-infrared II of lanthanide nanoprobes conjugated with Au (LNPs-Au) for temperature sensing and controlled photothermal therapy

•The intelligent composite nanoparticles of LNPs-Au were carefully constructed.•The LNPs-Au can act a nano temperature probe in living body using FIR technique.•The LNPs-Au achieved controllable PTT based on accurate temperature detection.•The LNPs-Au with emission in NIR II achieved fluorescence imaging of deep tissue.