Understanding and manipulating luminescence in carbon nanodots

Carbon nanodots (CDs), a new star in the carbon nanomaterials family, have been demonstrated to show strong luminescence, and can meet the needs of large-scale production for biological and medical applications due to their low toxicity and biocompatibility. However, their luminescence mechanisms, such as color tuning and strong excitation-dependent luminescence, are still unclear. Herein, we present a state-of-the-art understanding and manipulating luminescence in CDs by changing their environmental states and using multiple spectroscopic methods as well as the first-principles theoretical calculations. Our study reveals that the edge-carbon atoms and incorporated nitrogen atoms play critical roles in the luminescence mechanisms of CDs, and thus paves the way for manipulation of luminescence in CDs.