Recent Advances in Rare-Earth-Doped Nanoparticles for NIR-II Imaging and Cancer Theranostics

Fluorescence imaging in the second near infrared window (NIR-II, 1,000–1,700 nm) has been widely used in cancer diagnosis and treatment due to its high spatial resolution and deep tissue penetration depths. In this work, recent advances in rare-earth-doped nanoparticles (RENPs)—a novel kind of NIR-II nanoprobes—are presented. The main focus of this study is on the modification of RENPs and their applications in NIR-II in vitro and in vivo imaging and cancer theranostics. Finally, the perspectives and challenges of NIR-II RENPs are discussed.