Due to the relatively weak fluorescence and high fraction of PPcy, PPD2 and PPC5 NPs are more suitable for photoacoustic (PA) imaging and photothermal therapy (Figure , S27 & S28). The photothermal efficiency of PPC10, PPC5 and PPD2 NPs was examined by NIR laser irradiation at 808 nm with a power density of 2 W/cm 2 for 15 min. The temperature of PPD2 NPs (0.1 mg/mL) increased to 60 o C and maintained constant. In contrast to the photothermal behavior of PPD2 NPs, the temperature of PPC5 and PPC10 NPs slightly decreased after reach of the maximum (53.4 and 50.8 o C, respectively), which could be due to the photothermally reduced absorbance at 808 nm of PPC5 and PPC10 NPs (Figure ).