A novel ratiometric fluorescent probe for detection of iron ions and zinc ions based on dual-emission carbon dots

Herein, we developed a facile route for the preparation of dual-emission carbon dots (DCDs) by carbonizing glutathione in the water/formamide mixture. The synthesized DCDs displayed dual emission band respectively at 470 nm and 655 nm under the single-wavelength excitation at 400 nm, which can be used for the detection iron ions (Fe3+) and zinc ions (Zn2+) in different pH environments. An obvious fluorescence quenching around 655 nm was detected with the addition of Fe3+ in acidic environments, and a linear range of 2.5-30 mu mol.L-1 and a detection limit of 0.8 mu mol L-1 for Fe3+ were achieved. Moreover, another fluorescence quenching at 470 nm was also observed with the addition of Zn2+ in alkaline environments, and a linear range of 2.5-50 mu mol L-1 and a detection limit of 1.2 mu mol L-1 for Zn2+ were achieved. The prepared DCDs was used as a ratiometric fluorescent probe for determination of Fe3+ and Zn2+ ions in serum samples.