Fe(Ⅲ)-Oxidized Graphitic Carbon Nitride Nanosheets as a Sensitive Fluorescent Sensor for Detection and Imaging of Fluoride Ions

Since excess fluoride ions may lead to a severe health hazard, it is imperative to design a facile and sensitive sensor to detect it in both environmental and biological systems. The reported methods are always subjected to some limits, hampering their practical application. Herein, a two-dimensional turn-on fluorescent sensor, Fe 3+ -integrated oxidized graphitic-phase carbon nitride nanosheets (Fe-g-CNO), was synthesized via a facile and green method for sensitive detection of fluoride ions. The interactions between the C-N/C = N moieties of oxidized graphitic-phase carbon nitride (g-CNO) and Fe 3+ caused fluorescence quenching of g-CNO. Upon addition of F- ions, the fluorescence was recovered through the formation of complex of Fe 3+ and F-. The limit of detection of the sensor was 1 × 10 -6 M. Furthermore, this probe could be used as an imaging agent of fluoride ions in living cells and teeth for diagnosis of dental fluorosis. The work provides a safe and efficient platform for further environmental and biomedical uses.