Magnetic fluorescent carbon dots synthesized via one-pot approach for tumor photothermal therapy.

Carbon dots (CDs) exhibit low toxicity and excellent biocompatibility, endowing them with great potential in tumor photothermal therapy (PTT). However, existing magnetic-targeting CD composites are plagued by complex synthesis processes and fluorescence quenching issues. In this work, core-shell structured CDs@Fe3O4 is synthesized via a one-step microwave hydrothermal method. It integrates magnetic responsiveness, solid-state fluorescence, and photothermal conversion capabilities-with polyethyleneimine (PEI) acting as a bifunctional linker to bridge Fe3O4 nanoparticles and CDs, forming a puffy cluster structure that mitigates aggregation-induced fluorescence quenching (AIQ) for efficient solid-state emission. Notably, its magnetic property enables enrichment at target sites under external magnetic fields, while its photothermal effect efficiently converts laser energy into heat for tumor ablation. These features highlight CDs@Fe3O4 as a promising magnetically targeted photothermal agent for precision cancer therapy.