Bright Green-Emissive Carbon Nanodots for Sensing and Intracellular Imaging of Cu 2+ and Glutathione.

Green-emissive carbon nanodots (CDs) with high quantum yield are prepared. The abundant functional groups on the surfaces of CDs can selectively interact with Cu 2+ . The formed cupric amine complexes induce significant fluorescence quenching. The "on-off" switching can be further adjusted to the fluorescence "on" mode by the introduction of glutathione (GSH), which hinders the interactions between CDs and Cu 2+ . Based on the fantastic optical behavior of CDs, highly sensitive detection of Cu 2+ and GSH can be achieved. Intracellular imaging of the two targets is also validated.