Er/Tm based NIR-III dual-band emissive bioprobe for imaging and temperature readout

NIR-III emissive bioprobes have shown fascinating prospects owing to their ultralow scattering in biological tissues. Currently, only Er3+1.5μm emission band is available for lanthanide ions based NIR-III bioprobes, which highly restrains their practical uses. Herein, we construct a core–shell structured bioprobe comprises a Er3+ heavily doped core and a dilute Tm3+ doped shell, yielding NIR-III emission bands centered at 1.5μm and 1.8μm, respectively, upon 0.8μm excitation. The dual-band NIR-III emissions of the bioprobe expands the signal channel, and thus validates better temperature sensing performance via the widely-used luminescence intensity ratio method. The formed bioprobe can therefore be utilized for the deep-tissue bioimaging and temperature readout.