Figure 8.

Hela cells were incubated with (a–d) NaYF₄:Tm³⁺/Yb³⁺@MOF-Y:Eu³⁺ supernatant, (e–h) NaYF₄:Tm³⁺/Yb³⁺@MOF-Y:Eu³⁺ solution, and (i–l) NaGdF₄:Tm³⁺/Yb³⁺@MOF-Gd:Eu³⁺ solution; the fluorescence microscopy images were irradiated with a laser at 980 nm.