Characterization of GQDs. (a) PL and excitation (PLE) spectra of GQDs. (b) PL spectra of GQDs excited at different wavelengths varied from 390 to 490 nm. (c,d) The temperature change of the GQDs solution (500 μg/mL) under NIR laser irradiation (808 nm, 1.44 W/cm2) for 8 min. (e) The temperature change of the GQDs solution under NIR laser irradiation (808 nm, 1.44 W/cm2) with different concentrations for 5 min. (f) The temperature change of the GQDs solution of 300 μg/mL under 808 nm laser irradiation with different power for 5 min. (g) The photostability of GQDs of 200 μg/mL under NIR laser irradiation (808 nm, 1.44 W/cm2). (h) The temperature change of GQDs, GQDs@CCM, and GQDs/DOX@CCM solutions under NIR laser irradiation (808 nm, 1.44 W/cm2), and the GQDs concentration in all groups was 100 μg/mL.