Carbon dots for fluorescence bioimaging: Advances in synthesis, optical properties, and multimodal applications

Carbon dots (CDs) are an emerging class of carbon nanomaterials distinguished by exceptional optical properties, biocompatibility, and tunable surface chemistry, making them highly attractive for next-generation biomedical imaging. Unlike conventional semiconductor quantum dots, CDs are nontoxic, free of heavy metals, resistant to photobleaching, and readily synthesized via green, scalable routes. Advances in size control, surface modification, and heteroatom doping have enabled near-infrared emission, essential for deep-tissue imaging with minimal autofluorescence. This review summarizes recent progress in top-down and bottom-up synthetic strategies, emphasizing the mechanism property relationships that link…