Mesoporous silica-coated NaYF4:Yb3+, Er3+ particles for drug release

NaYF4:Yb3+, Er3+ nanoparticles were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. These NaYF4:Yb3+, Er3+ nanoparticles can be coated with mesoporous silica using nonionic triblock copolymer EO20PO70 EO20 (P 123) as structure-directing agent and other materials. The composites can load ibuprofen and release the drug in the phosphate buffer solution (PBS). The composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen absorption/desorption isotherms, fluorescence spectra, and UV/Vis absorption spectra, respectively. The composites have the mesoporous structure. In addition, the composites emit red fluorescence (from Er3+) under 980 nm near infrared laser excitation, which can be used as fluorescent probes in the drug-delivery system.