A New Generation of NIR‐II Probes: Lanthanide‐Based Nanocrystals for Bioimaging and Biosensing

Abstract Fluorescence‐based imaging in the second near infrared window (NIR‐II, 1000–1700 nm) is extensively used in both fundamental scientific research and clinical practice, owing to its advances of high sensitivity and high spatiotemporal resolution with increasing tissue penetration depths. Among several NIR‐II fluorophores, recent accomplishments in biocompatible lanthanide‐based luminescent nanomaterials have aroused great interest of researchers. This progress report summarizes recent progress in controlled synthesis of lanthanide‐based NIR‐II nanomaterials and their state‐of‐the‐art in NIR‐II biomedical imaging and biosensing applications. In addition, challenges and opportunities for this kind of novel NIR‐II nanoprobes are also discussed.