Indocyanine green derived carbon dots with significantly enhanced properties for efficient photothermal therapy

A simple yet effective strategy to enhance the properties of traditional dye indocyanine green (ICG) in all aspects was proposed and demonstrated. Specifically, indocyanine green-derived carbon dots (ICGCDs) were synthesized from ICG via a simple hydrothermal treatment. The ICGCDs exhibited significantly enhanced thermal stability and anti-photobleaching compared to ICG. Furthermore, their photothermal properties were also notably strengthened, in which a wider functional pH range, 50% improvement in photothermal conversion efficiency and superior photothermal cyclability were achieved. Thanks to these superior properties, ICGCDs were demonstrated as efficient NIR bioimaging and photothermal agents in both in vitro and in vivo experiments. Most excitingly, the strategy demonstrated in this study is likely to have broad applications in other systems.