b2815 Tissue Engineering and Nanotheranostics “9.61x6.69”114 Tissue Engineering and Nanotheranostics
for amine surface. Fig. 7(b) shows the TEM image of NaGdF 4 :Yb/
Tm@SiO 2 @TiO 2. Further, Shi et al. designed a NaYF 4 :Yb/Er/Tm@
NaGdF 4 UCNPs (Gd–UCNPs) as the core and used reverse microe-
mulsion method for silica coating, and finally utilized CTAC template
to deposit mesoporous silica shell on Gd–UCNPs@SiO 2 , shown as
Gd-UCNPs@SiO 2 @mSiO 2. Figure 7(c) showed the schematic dia-
gram and TEM pictures related to the growth process presented in
Figs. 7(d)–7(f).
Another complex example of core–shell paramagnetic hybrid nano-
structure was presented by Jin et al.^54 They demonstrated a novel
approach to fabricate multifunctional GdOF:Ln@SiO 2 yolk-like micro-
capsules. The preparation method (Fig. 8) illustrated the core Gd(OH)x
(CO 3 )yFz material synthesized using a precipitation method, and then
glucose used for carbon coating on Gd(OH)x(CO 3 )yFz:Ln via hydrother-
mal process. Later, a popular technique, Stöber method of silica coating
was applied on Gd(OH)x(CO 3 )yFz:Ln@C and finally calcined at 700°C
Fig. 7. (a) Synthesis process and (b) TEM picture of FA–Gd–Si–TiNPs. (c) complex
fabrication procedure of mesoporus silica-coated Gd–UCNPs–SiO 2 and (d)–(g) cor-
responding TEM pictures of various growth phases. Reprinted with permission from
Refs. 52 and 53.