Recent Advancement in Functional Core-Shell Nanoparticles of Polymers: Synthesis, Physical Properties, and Applications in Medical Biotechnology

Figure 19

Upconversion spectra of PEG(2000) phosphate-coated NPs in water. (a) NaYF₄:Er³⁺ 2 mol %, Yb³⁺ 20 mol%, and NaYF4:Er³⁺ 2 mol %, Yb³⁺ 20 mol%/NaYF₄ core-shell NPs. (b) NaYF₄:Tm³⁺ 0.5 mol %, Yb³⁺ 30 mol%, and NaYF4:Tm³⁺ 0.5 mol%, Yb³⁺ 30 mol%/NaYF₄ core-shell NPs. All samples dispersed as 1 wt % colloids in water [41].

(a)

(b)