A facile approach to synthesize SiO(2) · Re(2)O(3) (Re = Y, Eu, La, Sm, Tb, Pr) hollow sphere and its application in drug release

Multifunctional SiO(2) · Re(2)O(3) (Re = Y, Eu, La, Sm, Tb, Pr) hollow spheres (HSs) have been fabricated using an acidic Re(3+) ion solution. Under ultraviolet radiation, functional HSs emit different colors of light according to the different rare-earth ions embedded into the shell of SiO(2) hollow spheres. The as-prepared hollow capsules were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller method, scanning electron microscopy, and energy-dispersive spectrometry. Drug loading and release experiments have been carried out using SiO(2) · Eu(2)O(3) HSs that acted as drug carriers. The results demonstrate that the multifunctional HSs exhibit a high storage capacity and the ability of retaining drug stability and activity, which indicates that the as-synthesized fluorescent hollow capsules are a potential candidate as drug delivery materials.