Fig. 3. (A) Schematic illustration of the preparation method of NIR-II AIE nanoparticles (HLZ-BTED dots) via micellization. (B) Representative TEM image of the HLZ-BTED dots. Scale bar: 100 nm. (C) UV-vis-NIR absorption spectrum and NIR-II fluorescence emission spectrum (785 nm laser excitation) of the HLZ-BTED dots in aqueous solution. (D) Photo-stability test of the AIE HLZ-BTED dots in water, PBS, fetal bovine serum (FBS) and ICG in water under continuous 808 nm laser (180 mW cm^–2) irradiation for 60 min. (E) Quantitative analysis of the NIR-II fluorescence intensity of the HLZ-BTED dots in water, PBS, and FBS after 2 min to 30 h incubation.