The synthesis of fluorescent carbon dots from mango peel and their multiple applications

Mango peel was chosen as the carbon source to generate carbon dots (CDs), for its green and potential satisfactory photoluminescent nature in addition to the waste recycling usage of mango peel. An eco-friendly approach which combined pyrolyzation with oxygenolysis was adopted to produce CDs from mango peel without any other treatment. The prepared CDs were 2-6 nm nanoparticles with a high fluorescence quantum yield of 8.5 +/- 0.2%. Additionally, the CDs exhibited excellent fluorescent stability towards salt and ultraviolet irradiation, and reversible fluorescence between acid and base conditions. Owing to their low toxicity, good biocompatibility and multicolor fluorescence, CDs were successfully applied to cellular labeling on A549 cells in three colors (blue, green and red). Additionally, the fluorescence of CDs could be significantly quenched by Fe2+. Thus the CDs were applied as the fluorescent probe for detection of Fe2+ in ferrous succinate tablets with the linearity range of 4 mu M-16 mu M and the detection limit of 1.2 mu M. The CDs from the mango peel were promising for multiple applications.