Lanthanide-based upconverting nanoparticles are synthesized, spectroscopically interrogated and physically characterized in the Therien laboratory. These research efforts are currently focused on developing particles that absorb NIR radiation and emit in the UV and high-energy visible spectral regions. As tissue absorption is minimal in the NIR, these materials can be used to generate light in vitro and in vivo for biomedical imaging applications and for energy transfer to and subsequent activation of various drugs deep within tissue.
The emissive signatures of these materials can be tuned through compositional variation of both the host crystal and the lanthanide dopants, and we have recently demonstrated a material that exhibits a unique, prominent emission in the UV. In addition to engineering particles with desirable emissive properties, it is necessary to tailor the particle diameter and surface chemistry to facilitate cellular uptake. This image shows bright visible emission (blue) from 50 nm, PEI-coated YbF3 particles, which have been incorporated into cells (red).