Far-Red to Near-Infrared Carbon Dots: Preparation and Applications in Biotechnology.

As novel fluorescent nanomaterials, carbon dots (CDs) exhibit excellent photostability, good biocompatibility, and high quantum yield (QY). Their superior properties make them promising candidates for biomedical assays and therapy. Among them, the red-emission (>600 nm) CDs have attracted increasing attention in the past years due to their little damage to the biological matrix, deep tissue penetration, and minimum autofluorescence background of biosamples. This Review, summarizes the recent progress of far-red to near-infrared (NIR) CDs from the preparation and their biological applications. The challenges in designing far-red and NIR CDs and their further applications in biomedical fields are also discussed.