Biomedical applications of lanthanide-doped upconversion core-shell nanostructures

Lanthanide-doped upconversion nanoparticles possess superior physicochemical features such as excellent photostability, continuous emission capability, and sharp multi-peak line emission, which have been shown great potential applications in the biomedical field. However, the further development of conventional upconversion nanoparticles in the field of biomedical has been hindered by low upconversion efficiencies associated with surface quenching effect. The core-shell design of these nanostructures not only remedy the inherent defects of nanoparticles, but also bring a series of innovation performance and wide application. This review summarized four kinds of light upconverting core-shell nanostructures of most prevalence in recent years, as well as their structural characteristics and research status, and the latest research progress in the field of biomedical is reviewed in detail. It is anticipated that the present review will deepen peoples understanding of this field and hence contribute to guide the future design of novel core-shell structures.