Luminescent surface-functionalized mesoporous core-shell nanospheres and their cytotoxicity evaluation

Publication date: Available online 19 April 2019Source: Colloids and Surfaces A: Physicochemical and Engineering AspectsAuthor(s): Anees A Ansari, Maqsood A Siddiqui, Aslam Khan, N. Ahmad, M. Alam, Ahmed Mohamed El-Toni, Abdulaziz A. Al-KhedairyAbstractSpherical shaped SiO2@Tb(OH)3 nanospheres (core-shell NSs) with an average grain size of 300-350 nm were successfully synthesized at a large scale via sol-gel process with subsequent heat treatment. XRD results demonstrated the non-crystalline nature of the sample even after coating with terbium hydroxide. TEM and SEM images clearly showed that the prepared sample was highly monodispersed, perfectly spherical in shape, and mesoporous with narrow size distribution (an average crystalline size of 350 nm). XRD, TGA, TEM, SEM, and EDX results demonstrated that the terbium hydroxide layer was effectively grafted over the surface of the silica spheres, which was further verified using FTIR, UV/Visible, and emission spectral results. The emission spectrum of core-shell NSs demonstrates that Tb3+ is strongly bonded covalently to the silica framework with surface anchored oxygen atoms, thus preventing the accumulation of Tb3+ ions to give an efficient luminescence. The emission spectrum was dominated by 5D4→4F5 of the Tb3+ ion located in the green region at 2.88 eV along with broad emission of the silica framework. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) bromide and neutral red uptake assays on MCF-7 and A...
Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Category: Chemistry Source Type: research