Lanthanide-Based Nanoprobes for Time-Resolved Luminescence Imaging on Various Ions and Molecules

Abstract

Lanthanide-doped upconversion nanoparticles (Ln-UCNPs) have been extensively explored in the biological field. In particular, Ln-UCNPs with near-infrared (NIR) fluorescence have tremendous potential for biological imaging because of their outstanding photo-and chemo-stability, extended photoluminescence lifetimes, low long-term toxicities and narrow photoluminescence bandwidths as well as minimal background interferences. Using predesigned energy transfer routes makes it possible to get upconversion luminescence from lanthanides' 4f-4f optical transitions. This article clarifies the key working principles and superiorities of Ln-UCNPs for bioimaging. A crucial overview of recent advances in biological detection adopting lanthanide-based luminescence resonance energy transfer (LRET) mechanisms is presented while emphasizing the importance of modifying Ln-UCNPs to obtain a more efficient energy transfer mechanism.