Fig. 4: Photophysical properties of C5T-Pc and C5T-Pco NPs.

a TEM images of C5T-Pc and C5T-Pco NPs. The results are represented of n = 1 independent experiment. (Scale bar: 250 nm). b Absorption spectra of C5T-Pco NPs ([C5T-Pco] = 50 µg mL⁻¹) with different mass concentrations of F127; c PL spectra of C5T-Pco NPs with different mass concentrations of C5T-Pco (λ_ex = 700 nm) when fixing the concentration of F127 (25 mg mL⁻¹). d PL spectra of C5T-Pc and C5T-Pco NPs (λ_ex = 700 nm). Normalized absorption spectrum, normalized excitation spectrum (λ_em = 796 nm (e) or λ_em = 824 nm (f)), and normalized emission spectrum (λ_ex = 700 nm) of 5 µg mL⁻¹ C5T-Pco THF solution (e) or 100 µg mL⁻¹ C5T-Pco NPs (f). g PL spectra for absolute Φ_PL tests of 100 µg mL⁻¹ ICG water solution and C5T-Pco NPs, inset is NIR-II fluorescence image of C5T-Pco NPs. h NIR-II fluorescence images of capillary tubes filled with ICG water solution or C5T-Pc and C5T-Pco NPs ([cyanine] = 100 μg mL⁻¹), masked with the fat emulsion injection with different depths. (λ_ex = 808 nm, 1100 nm long-pass filter, 100 ms exposure time, 30% laser intensity).