Porphyrin-Based Carbon Dots: Navigating the Nanoscale Frontier of Precision Biomedicine

As natural aromatic macrocyclic compounds with an 18-π electron system, porphyrins exhibit key values in multiple fields such as biosensing, imaging, and photothermal/photodynamic therapy due to their unique photophysical properties and chemical tunability. Their integration with low-toxicity carbon dots (CDs) with tunable optical and physicochemical properties has opened diverse innovative pathways for interdisciplinary nanotechnology research. This review presents a critical analysis of porphyrin-based CDs (p-CDs), highlighting their structural versatility and transformative applications in nanomedicine. By integrating porphyrin's photophysical prowess with CDs' biocompatibility, these hybrid materials enable breakthroughs in near-infrared bioimaging, enzymatic-optical dual sensing, and synergistic phototherapies. Synthetic strategies, including covalent π-conjugation, natural precursor carbonization, and metal-nanozyme engineering, are discussed to underscore their structure-activity relationships. In the landscape of biomedicine, p-CDs have emerged as a revolutionary tool, facilitating early disease detection, precise molecular diagnosis, and targeted therapeutic interventions, thereby reshaping the paradigms of clinical practice and patient care. However, challenges remain in large-scale production and biocompatibility assessment. Future research should prioritize biomimetic design and multimodal integration to realize the full potential of p-CDs in precision medicine.