Fig. 2.

Characterization of as-prepared nanoparticles. (A) UV-vis-NIR absorption and (B) fluorescence spectra of CydtPy, CydtPy:Fe²⁺, and CydtPy:Mn²⁺ in DMSO. Fluorescence spectra of CydtPy upon the addition of (C) Mn²⁺ ions and (D) Fe²⁺ ions (0 to 8 eq). DLS and TEM images of (E) LET-11, (F) LET-11-Fe, and (G) LET-11-Mn. (H) Cyclic photothermal heating and cooling of LET-11, LET-11-Fe, and LET-11-Mn (808 nm, 0.3 W cm⁻²). (I) Photostability of LET-11, LET-11-Fe, and LET-11-Mn under laser irradiation (808 nm, 1 W cm⁻²). a.u., arbitrary units.