Figure 1.

Upper: Cartoon illustration on a carbon dot, which is generally a small carbon nanoparticle core with attached and strongly adsorbed surface passivation molecules (a configuration similar to a soft corona). (Reprinted with permission from ref. 30) Lower: Aqueous solution of a representative sample of CDots (a) excited at 400 nm and photographed through band-pass filters of different wavelengths as indicated, and (b) excited at the indicated wavelengths and photographed directly. (Reprinted with permission from ref. 31).