Tunable luminescence and cytotoxicity of Samarium-doped calcium–strontium–hydroxyapatite for cell imaging

Abstract

Samarium (Sm)-doped calcium–strontium–hydroxyapatite (Ca–Sr–HA:Sm) materials were designed and prepared, and the influence of Sr-introduction on the structure, photoluminescence (PL) and cytotoxicity of samples was revealed. The Sr-doping deduces the shift of some diffraction peaks to smaller angles and enlarges the particle size of samples. The typical red– orange emissions and corresponding luminescence quenching of Sm[Formula: see text] were observed, and the optimal luminescence performance appeared when [Formula: see text](Sr) = 7(Sr/Ca = 7/3) and quenching concentration closes to [Formula: see text](Sm) = 0.8 mol.%. The non-radiative transitions and energy transfers due to the dipole–dipole interactions between ions with different symmetry are essential to the luminescence and quenching of Sm[Formula: see text]. Furthermore, the viability values of human HepG2 cells are calculated larger than 90%, and the red–orange color emission was observed when the particles are incubated with cells.