In vitro photothermal and photoacoustic imaging effect of DFTNPs. (A) Photothermal curves of DFTNPs with 808 nm laser irradiation (2.0 W/cm2, 10 min) at different concentrations (50, 100, 200, 300 and 400 μg/mL). (B) Photothermal curves of DFTNPs dispersed in aqueous solution irradiated under increased power densities (0.5, 1.0, 1.5 and 2.0 W/cm2). (C) Infrared thermal images in vitro. (D) Photothermal curves of the aqueous dispersion of DFTNPs, DoxNPs, Fe3+/TA complex, TA and ferric chloride. (E) Photothermal performance of the aqueous dispersion of DFTNPs under 808 nm laser irradiation at the power intensity of 2.0 W/cm2 for periods and the laser was cut off when the temperature tended to be stable. (F) The temperature changes of DFTNPs solution (400 µg/mL) under laser irradiation (808 nm, 2 W/cm2) for 600 s followed by the cooling period. (G) The time constant for heat transfer calculated from the cooling period. (H)
In vitro PA imaging intensities of DFTNPs with various concentrations.