Fig. 6. Different CQDs synthesized through different controlled carbohydrate carbonization methods, the solution containing CQDs and regarding absorption (solid line), excitation (dashed line) and emission (colored line) spectra; the emission spectra are recorded by excitation at 370 nm for blue CQDs, at 400 nm for green CQDs, at 425 nm for yellow CQDs, and at 385 nm for red CQDs, reprinted with permission from ref. 155, copyright 2013 Springer Nature.