Polymer nanodots of graphitic carbon nitride as effective fluorescent probes for the detection of Fe3+ and Cu2+ ions

A simple and green route was developed for the first time to produce fluorescent graphitic carbon nitride (Fg-C3N4) by hydrothermal treatment of bulk g-C3N4. The produced F-g-C3N4 dots have blue emission and a high quantum yield, and were applied as a very effective fluorescent probe for label-free selective and sensitive detection of Cu2+ and Fe3+ ions; the limits of detection were as low as 0.5 nM and 1.0 nM, respectively. By using sodium hexametaphosphate (SHPP) as a masking agent of Fe3+, Cu2+ was exclusively detected in the presence of Fe3+ ions. Cu2+ and Fe3+ ions in real water samples were also detected successfully. This exceptional fluorescent performance makes the probes based on F-g-C3N4 dots attractive for highly sensitive detection of Cu2+ and Fe3+ ions in real water.