Fig 1.

Nanoparticle characterization. (A) The structures of main components of nanoparticles. (B) Size distribution based on dynamic light scattering measurement (C) Cryogenic Scanning Electron Microscopy (D) ¹⁹F NMR spectrum of PLGA-PFCE-ICG nanoparticles in D₂O, here Trifluoroacetic acid (TFA) was used as a reference. (E) Fluorescence image of nanoparticles at the concentration of 10 mg/ml. Nanoparticles were excited at 745 nm (F) ¹⁹F MR image of 1 mg/ml nanoparticles in a phantom acquired on a clinical scanner (false color). (G) PA spectrum of nanoparticles and free ICG dye measured in vitro.