Fluorine-18 labeled rare-earth nanoparticles for positron emission tomography (PET) imaging of sentinel lymph node

Rare-earth-based nanoparticles have attracted increasing attention for their unique optical and magnetic properties. However, their application in bioimaging has been limited to photoluminescence bioimaging and magnetic resonance imaging. To facilitate their use in other bioimaging techniques, we developed a simple, rapid, efficient and general synthesis strategy for 18F-labeled rare-earth nanoparticles through a facile inorganic reaction between rare-earth cations and fluoride ions. The 18F-labeling process based on rare-earth elements was achieved efficiently in water at room temperature with an 18F-labeling yield of >90% and completed within 5 min, with only simple purification by aqueous washing and centrifugation, and without the use of organic agents. The effectiveness of 18F-labeled rare-earth nanoparticles was further evaluated by positron emission tomography (PET) imaging of their in vivo distribution and application in lymph monitoring. In addition, this strategy is proposed for the creation of a dual-model bioimaging technique, combining upconversion luminescence bioimaging and PET imaging.