“…While organic dyes often show poor photostability, fluorescent nanomaterials offer the advantages of a high quantum yield, a large Stokes shift, but above all high photostability and chemical stability. − For this reason, different types of fluorescent nanomaterials, including semiconductor quantum dots, noble metal nanoparticles, , and carbon nanomaterials, have been explored. In recent decades, research has begun to focus on the use of rare earth nanoparticles, whose interesting optical properties, such as narrow emission bandwidths and high resistance to photobleaching, high chemical stability, and low cytotoxicity, make them excellent candidates for biological applications.…”