Near-infrared carbon dots: pioneering emerging frontiers in biomedical applications

Carbon dots (CDs) are fluorescent carbon-based nanomaterials with sizes smaller than 10 nm, that are renowned for their exceptional properties, including superior antiphotobleaching, excellent biocompatibility, and minimal toxicity, which have received significant interest. Near-infrared (NIR) light has emerged as an ideal light source in the biological field due to its advantages of minimal scattering and absorption, long wavelength emission, increased tissue penetration, and reduced interference from biological backgrounds. CDs with efficient absorption and/or emission characteristics in the NIR spectrum have shown remarkable promise in the biomedical uses. This study provides a comprehensive overview of the preparation methods and wavelength modulation strategies for near-infrared CDs and reviews research progress in their use in the areas of biosensing, bioimaging, and therapy. It also discusses current challenges and clinical prospects, aimed at deepening our understanding of the subject and promoting further advances in this field.