Fig 1

(a) Schematic of the synthesis of different CDs assembles. Optical images of S-d-CDs, S-a-CDs, and S-d/a-CDs in solutions and powder. (b) Absorption spectra of different CDs and CDs assembles in aqueous solutions at 100 µg∙mL−1. (c) PL spectra of S-d-CDs, S-a-CDs, and S-d/a-CDs in aqueous solutions at 100 µg∙mL−1 under 655 nm excitation. (d) Temperature evolutions of the S-d-CDs, S-a-CDs, and S-d/a-CDs in aqueous solutions at 100 μg∙mL−1 under 740 nm laser irradiation at 1 W∙cm−2. (e) Temperature evolutions of the S-d/a-CDs aqueous solution at 100 µg∙mL−1 under 740 nm excitation at various power densities. (f) Temperature evolutions of the S-d/a-CDs aqueous solution at various concentrations under 740 nm laser irradiation. (g) Temperature curves of the S-d/a-CDs aqueous solution at 100 μg∙mL−1 under five cycles of photothermal heating under 750 nm laser irradiation (1 W∙cm−2)."

Fig 2

TEM, HRTEM (inset) images of (a) S-d-CDs, (b) S-a-CDs, and (c) S-d/a-CDs. N 1s and O 1s spectra of (d, g) S-d-CDs, (e, h) S-a-CDs, and (f, i) S-d/a-CDs. FT-IR spectra of (j) d-CDs, S-d-CDs, (k) a-CDs, S-a-CDs, and (l) S-d/a-CDs."

Fig 3

2D pseudo-color plot of TA spectra of (a) S-d-CDs, (b) S-a-CDs, and (c) S-d/a-CDs in water. Time-dependent TA spectra of (d) S-d-CDs, (e) S-a-CDs, and (f) S-d/a-CDs in water at specified delay times. TA kinetic trajectories of (g) S-d-CDs, (h) S-a-CDs, and (i) S-d/a-CDs collected at 580, 640, and 700 nm in water at pump wavelengths of 400 nm. The dot is the experimental point, and the solid line is the fitting line."

Fig 4

(a) Structural models. (b) Calculated HOMO-LOMO energy levels of models of the Conjugated graphene plate, plate+ ―OH*3, plate + ―NH2*3, plate + ―COOH*3. (c) Schematic energy level transition diagram of the bare CDs, d-CDs, and a-CDs. (d) Energy level transition diagrams of S-d-CDs, S-a-CDs, and S-d/a-CDs."

Fig 5

Dose gradient dark toxicity (6.25–100 µg∙mL−1) of S-d-CDs, S-a-CDs, and S-d/a-CDs in (a) 4T1; (b) HeLa. Phototoxicity evaluation of CDs under 1 W∙cm−2 740nm laser, 10 min irradiation in (c) 4T1 and (d) HeLa. (e) Cellular uptake kinetics (0, 1, 6, 12, 24 h). (f) Spatiotemporal localization of S-d/a-CDs (red)/nuclear (DAPI, blue). (g) Live (Calcein AM, green)/dead (PI, red) cell imaging assays of the control group and S-d/a-CDs. (h) TNF-α, and (i) IL-1β release of the 4T1 cells treated with PBS (Control group), S-d-CDs, S-a-CDs, S-d/a-CDs."

Fig 6

(a) Thermographic monitoring of mice irradiated by 740 nm laser, 1 W∙cm−2 at 0, 2, 5, 8 min post-injection of PBS or CDs (0.1 mL, 1 mg∙mL−1 via tail vein). (b) H & E of the tumor tissues on day 2 for PBS and S-d/a-CDs. (c) Tumor growth suppression curve of 18 days observation period. (d) Representative tumor images. (e) Tumor weight quantification. (f) Photographs of mice at days 0, 2, 8, and 18 post-treatment. Data represent mean ± SD (n = 5). Statistical significance between groups was determined by one-way ANOVA. *p < 0.05, **p < 0.01, **p < 0.001, ****p < 0.0001, ns = not significant."