Multicolor luminescence of carbon Dots: From mechanisms to applications

Multicolor carbon dots (MCDs) have emerged as prominent carbon nanomaterials due to their unique properties, which include good biocompatibility, high photostability, tunable luminescence, and a wide range of applications in sensing, biological imaging, light-emitting diodes, and anti-counterfeiting. However, there is currently a lack of comprehensive reviews addressing the structural origins and key factors that control the mechanisms behind the multi-emission of carbon dots, as well as innovative advancements in simultaneous multicolor applications. This mini-review aims to fill this gap by highlighting recent advancements in MCDs over the past five years (2018 to 2024). We provide a concise overview of systematic classification, controllable synthesis, and characterization techniques for MCDs. We then emphasize the multicolor emission characteristics of MCDs and the factors influencing them, such as surface state, quantum confinement effect, and graphitization degree. Additionally, we discuss simultaneous multicolor applications of MCDs and their potential in various fields, the current challenges and perspectives on MCDs will be discussed as well. By acquiring a profound understanding of the structure-performance relationship and employing suitable adjustment methods, it is anticipated that this review will inspire and guide future research endeavors in the tailored design of MCDs.