Nd³⁺-Doped LiLuF₄ Nanoparticles for Near-Infrared/Computed Tomography Dual-Mode Imaging

Nd 3+ ions are commonly employed as sensitizers in lanthanide luminescent nanoprobes. However, the cross-relaxation effect typically limits their doping concentration to less than 5%. To address this limitation, we synthesized and manipulated LiLuF 4:Yb,Nd nanoparticles through a rational design of the host lattice and optimization of the doping concentration, achieving up to a 50% doped Nd 3+ concentration. The nanoparticles’ morphology, energy transfer mechanisms, and luminescent properties revealed robust near-infrared luminescence and successful imaging of mouse blood vessels. Furthermore, the inclusion of Lu in the nanoparticles enabled X-ray computed tomography imaging, enabling dual-modal imaging capabilities. This study presents a strategy for enhancing the performance of lanthanide luminescent nanoprobes and expanding their applications in multimodal imaging.