Doxorubicin (DOX), a widely used chemotherapy drug for breast cancer, suffers from limitations such as non-specific toxicity and drug resistance. To address these challenges, we developed a novel drug delivery system (DDS) using porphyrin-derived carbon dots (CDs) as carriers for DOX. Porphyrin-based CDs were synthesized solvothermally from tetrakis(4-carboxyphenyl) porphyrin (TCPP) and urea. DOX was non-covalently loaded onto the CDs to form the DOX@CDs nanocomposite. The resulting CDs exhibited desirable properties like excellent water solubility, stability, and biocompatibility. Moreover, the DOX@CDs complex showed a high drug loading efficiency of 93% and a pH-responsive release profile, with enhanced release at acidic tumor microenvironments. The DOX@CDs nanocomposite demonstrated significantly improved cytotoxicity against human breast cancer MCF-7 and MDA-MB-231 cell lines (at IC