Near-infrared (NIR) lanthanide molecular probes for bioimaging and biosensing

Recent advances in NIR detector bloom the design of NIR fluorophores for bioimaging guided diagnosis and therapeutics, with reduced light-tissue interaction, enhanced signal-to-noise ratio and increased penetration depth. NIR lanthanide molecular probes represent an important and emerging group of NIR imaging and sensing materials with attractive structural and photophysical characteristics including small sizes, metal-centered emission, long decay lifetime, large Stokes shift and high resistance to photobleaching. In this review, the sensitization of lanthanides and design principle of lanthanide molecular probes were described. We summarized the recent progresses in last decade on NIR luminescent lanthanide molecular probes by precisely tuning the antenna ligands. The development tendency of applying lanthanide molecular probes for in vivo bioimaging and biosensing would also be discussed, showing the unique and attractive properties of lanthanide coordination compounds compared to organic molecules and inorganic quantum nanoparticles.