Controllable synthesis of bifunctional monodisperse gadolinium orthosilicate core-shell nanospheres

Rare-earth scintillator particles with uniform size have garnered significant attention in the biomedical field. In this study, monodisperse spheres of Gd 2 SiO 5 :Ce 3+ @SiO 2 (GSO:Ce 3+ @SiO 2 ) were synthesized via urea-based homogeneous precipitation and the Stöber method. Firstly, the growth process of the precursor spheres was studied by adjusting reaction conditions, including reaction temperature, reaction time, pH, RE 3+ ions and urea concentration. Secondly, the evolution of the core-shell structure of the precursor spheres following TEOS coating and calcination was discussed. Core-shell monodisperse spheres with a particle size of approximately 170 nm were obtained. Thirdly, the luminescence characteristics of GSO:Ce 3+ @SiO 2 was investigated under UV and X-ray excitation, and the effects of varying the thickness of the SiO 2 shell layer on the fluorescence properties of GSO:Ce 3+ @SiO 2 were discussed. The study revealed that the obtained GSO:Ce 3+ @SiO 2 exhibited excellent stability characteristics, blood compatibility and displayed a favorable spectral match with porphyrin-based photosensitizers in the blue-light region. The present work provides a promising nanomaterial with potential applications in biomedical fields, including X-ray photodynamic therapy and magnetic resonance imaging.