PREPARATION OF WATER-SOLUBLE SiO2 COATING Sr2MgSi2O7:Eu2+, Dy3+ FOR CELLS IMAGE

In the present study, afterglow materials of SiO2 coating Sr2MgSi2O7: Eu2+, Dy3+ (SiO2-PLNPs) of good water solubility were prepared by hydro-thermal co-precipitation method. Effects of SiO2 coating on the luminescence property, afterglow performance and water solubility of SiO2-PLNPs have been discussed by contrast with Sr2MgSi2O7: Eu2+, Dy3+ (PLNPs) phosphor. The phase structure examined by X-ray diffraction (XRD) and both them was tetragonal Sr2MgSi2O7. From the excitation spectrum, they two can be excited by light with a wavelength of 275 nm and 355 nm. Subsequently emission peak was recorded at 470 nm. The afterglow decay curves of the PLNPs and SiO2-PLNPs showed that optical signal can be detected with a persistent time of 2 h. Micro structure of PLNPs and SiO2-PLNPs were characterized by scanning electron microscope (SEM) and transmission electron microscopy (TEM) which demonstrated the success for the surface coating. Suspension property test suggested SiO2-PLNPs have a good water solubility compared with PLNPs. The death rate of cells was less than 10 % when SiO2-PLNPs solution of different concentration treat mouse osteoblasts. Bright blue light spots were visible to the eye in the dark field when the above cells excited by a 470 nm excitation light.