Highly Water-Soluble Luminescent Silica-Coated Cerium Fluoride Nanoparticles Synthesis, Characterizations, and In Vitro Evaluation of Possible Cytotoxicity

A coprecipitation process was utilized for the preparation of terbium fluoride nanocrystals by cerium fluoride. Silica was used to modify the surface of these core/shell nanocrystals. The synthesized CeF3:Tb@LaF3 and CeF3:Tb@LaF3@SiO2 nanoparticles (NPs) were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV/vis spectrophotometry, and photoluminescence spectrophotometry. XRD patterns showed resolved reflection planes with broad widths, confirming the nanocrystalline nature of the CeF3:Tb@LaF3@SiO2 NPs. Fourier transform infrared spectra clearly revealed a uniform, smooth silica layer encapsulating the luminescent seed core and confirmed the polycrystalline nature of the CeF3:Tb@LaF3@SiO2 NPs. The TEM result showed an average crystalline size of 18 nm, which illustrated good agreement with the XRD results. The results of photoluminescence spectrophotometry confirmed the doping of terbium ions in the CeF3 crystal lattice. The cytotoxicity results of the MTT assay showed that CeF3:Tb@LaF3@SiO2 NPs have minimum toxicity with respect to CeF3:Tb@LaF3 NPs and the control drug dasatinib on HT-29 and HepG2 cell lines. Moreover, results of inverted microscopy confirmed the nontoxic and biocompatible nature of CeF3:Tb@LaF3@SiO2 NPs. These findings show that CeF3:Tb@LaF3@SiO2 NPs are promising candidates for applications in biomedical science in the future, such as bioimaging, biolabeling, biodetection or bio-probing, labeling of cells and tissue, drug delivery, cancer therapy, and multiplexed analysis.