Cancer ranks as the top cause of death following cardiovascular diseases. Identifying cancer patients at early stages presents significant challenges due to the asymptomatic nature of early-stage tumors. Conversely, the advancement of therapy resistance has led to a reduction in cancer treatment efficacy. Consequently, utilizing nanoparticles for the diagnosis and treatment of cancer can greatly enhance the prognosis and results for patients. CDs are recognized entities in the pharmaceutical domain and have been extensively used for therapeutic purposes in disease treatment. These non-viral vectors have shown efficacy in inhibiting both solid tumors and hematological malignancies through targeted drug delivery. CDs can enhance the administration of medications and genes in cancer treatment by ensuring their continuous release. The stimuli-responsive CDs have enhanced the targeted delivery of payloads at the tumor location, responding to the stimuli in TME such as pH, redox and light. CDs can serve as effective carriers that enhance the efficacy of phototherapy by improving the solubility and delivery of phototherapeutic agents, enabling integration with chemotherapy and immunotherapy. The administration of immunomodulators through CDs can enhance cancer immunotherapy and boost the infiltration of immune cells. Ultimately, CDs can aid in cancer diagnosis and the identification of biomarkers.