Advances in near-infrared-activated lanthanide-doped optical nanomaterials: imaging, sensing, and therapy

As the population ages, cancer has become a major health concern. Although surgical treatment, chemoradiotherapy, and other clinical treatments have become dominant, their strong invasiveness and intolerable toxic side effects seriously affect patients' quality of life. Therefore, developing non-invasive optical therapy with high safety is of great significance. In the last two decades of development, great progress has been made in lanthanide doped nanoparticles on biomedical applications under near-infrared (NIR) light due to their unique properties. These nanomaterials have been used in a wide range of applications, including bioluminescence marker detection, in vitro and in vivo imaging, photodynamic therapy (PDT), photothermal therapy (PTT), and other therapeutic applications. These therapies have been rapidly developed in the profession involving oncology due to their non-invasive, spatiotemporal controllability, and high efficiency. For this key review, the applications based on lanthanide nanoparticles have been listed as follows: bioimaging, biosensors, PDT and PTT. Some emerging biological applications of lanthanide-doped nanoparticles currently at the forefront of the nano/biological interface are also discussed. Finally, this review summarizes the future opportunities and challenges of nanotechnology research based on lanthanide-doped nanoparticles.