Optimization of the Fabrication of Luminescent Nanocrystalline Ce<i>ₓ</i>La_1-xF₃:Tb³⁺ for XPDT Applications

This work presents an investigation into the synthesis, characterization, and luminescence properties of Ce<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub>La<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub>F3:Tb<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup>(5%) nanoparticles, synthesized using the sol-gel method with various solvents, including diethylene glycol (DEG), ethylene glycol monomethyl ether (EGME) and polyethylene glycol (PEG). The nanoparticles were subjected to calcination to study the effect of temperature on crystallinity, particle size, and luminescence efficiency. The stability of the nanoparticle suspensions and their potential for biofunctionalization were also evaluated for applications in X-ray induced photodynamic therapy (XPDT). X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses confirmed the size and phase composition of the nanoparticles, with TEM images showing good agreement with dynamic light scattering (DLS) results. Radioluminescence measurements revealed broad Ce<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> emission bands and characteristic narrow Tb<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> lines and confirmed efficient energy transfer between Ce<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> and Tb<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions. Notably, the sample prepared in EGME and annealed at 250 °C, as well as the sample synthesized in PEG and annealed at 320 °C, demonstrated the best combination of small particle size, enhanced luminescence, and stable suspensions, making them ideal for further biofunctionalization..