Concentration-tuned Multicolor Carbon Dots: Microwave-assisted Synthesis, Characterization, Mechanism and Applications
A new multicolor carbon dots made from D- fructose and NH4HCO3, which we call it as F-CDs, has been synthesized via a time-saving and energy-saving microwave-assisted method. By just adjusting the concentration, the optimal emission wavelength of F-CDs can be tuned from 404 nm to 583 nm. Further, the sp2 carbon core and abundant functional groups provided the foundation for the concentration-dependent photoluminescent properties. Besides, the relationship between the aggregation process and the concentration-induced photoluminescence mechanism was first fully discussed. And the maintaining of F-CDs’ PL intensity with the increasing of concentration was related to the mechanism similar to the crosslinked enhanced emission (CEE) effect. Finally, the highly stable and biocompatible multicolor F-CDs was successfully applied in ﬂuorescence ink and multicolor bioimaging.