Development of a visible-light-sensitized THA-based lanthanide nanocomposite for cell imaging

As is well-known, hydroxyapatite (HA, Ca10(PO4)6(OH)2) is a typical green natural material. Due to its good biodegradability and nontoxic properties, it is promising to act as a carrier of luminescent lanthanide complexes for the further applications. In this work, we synthesize the well-dispersed HA nanoparticles (NPs) by using SiO2 as templates (THA), which is subsequently grafted by a terpyridine derivative. Then, lanthanide europium complex Eu(DBM)3(H2O)2 (HDBM= dibenzoylmethane) is employed to covalently couple with modified THA NPs via ligand exchange reaction, generating a novel THA-based ternary europium nanocomposite. The formed nanocomposite has well dispersion stability and high biocompatibility. Furthermore, THA-based lanthanide nanocomposite exhibits the visible-light excitable feature with a wide excitation wavelength range from UV to visible light (a maximum at 397nm), long luminescence lifetime (303μs) and improved exposure durability. The excellent fluorescence and low cytotoxicity in cell study of the nanocomposite may result in the potential applications of cell imaging in biological systems. [Display omitted] •A novel THA-based lanthanide nanocomposite has been assembled.•THA-based lanthanide nanocomposite displays the visible-light excitable feature.•HeLa cell treated with the nanocomposite shows intense red luminescence.