Recent developments in lanthanide-based luminescent probes

Lanthanide-based luminescent probes have attracted increasing attention due to their unique optical properties, such as large Stokes and/or anti-Stokes shifts, long luminescence lifetimes (up to milliseconds), and narrow and compound-independent emission bands, making them widely employed in detection, diagnosis, and bioimaging. This review focuses on the recent developments of lanthanide-based luminescent probes including lanthanide complexes and lanthanide nanoparticles for probing pH, anions, metal ions, reactive oxygen species, and biomolecules (amino acids, proteins, nucleobases, and nucleic acids). The design principles and recognition mechanisms of luminescent probes based on lanthanide ions for various analytes are elaborated in detail. In the end, future research directions with great potentials and the according challenges of lanthanide-based luminescent probes are also discussed.