Luminescent nano‐bioprobes based on NIR dye/lanthanide nanoparticle composites

Abstract Near‐infrared (NIR) light, which has ignorable tissue scattering/absorption, minimal photodamage, and no autofluorescence interference, is highly favorable for bioapplications. NIR dye and lanthanide‐doped nanoparticle (LnNP), as representative NIR‐excited luminescence probes, have attracted increasing interest due to their unique optical property and low biological toxicity. Design of luminescence probes based on NIR dye/LnNP nanocomposites cannot only integrate the advantages but also achieve additional functions via regulating internal energy transfer pathways. In this review, we focus on the most recent advances in the development of NIR dye/LnNP nanocomposites as potential bioprobes, which cover from their fundamental photophysics to bioapplications, including energy transfer mechanisms, interface engineering (involving binding interaction, distance, and aggregation as key factors), and their applications for dye‐sensitized upconversion/downshifting luminescent bioimaging, detection of biomolecules, and NIR‐triggered diagnosis and therapy. Some future prospects and efforts toward this active research field are also envisioned.