Engineered carbon dot‑copper oxide nanohybrids for tumor-specific fluorescent imaging-guided chemodynamic therapy

Carbon dots (CDs) have garnered considerable interest in biomedical fluorescent imaging recently. However, their ultrasmall size has remained as a challenge in practical applications. Here, an engineered strategy was developed to fabricate carbon dot‑copper oxide (CDs-CuO) nanohybrids for tumor-specific fluorescent imaging-guided chemodynamic therapy (CDT). The optimized CDs-CuO nanohybrids with an averaged hydrodynamic diameter (D_h) of 134 nm and a Cu content of 10.15 % showed high stability with quenched fluorescence in the simulated normal physiological medium, while they could disintegrate into CDs and copper ions (Cu²⁺/Cu⁺) only in the simulated tumor intracellular microenvironment for fluorescent imaging and chemodynamic therapy, respectively. The in vitro cellular results indicated that the CDs-CuO nanohybrids could be cellular internalized and exhibited a tumor-specific chemodynamic therapy with a half maximal inhibitory concentration (IC₅₀) of 52.24 μg/mL on the human hepatocarcinoma cell (HepG2 cells), much lower than that of the normal human liver cell (L02 cells) of 63.59 mg/mL.