LAUSR

Abstract The ammonium citrate derived carbon quantum dot (C-dots) with strong fluorescence and high photostability were synthesized via one-step hydrothermal approach. Based on fluorescence quenching and fluorescence recovery of C-dots, the as-prepared C-dots were innovatively developed as an effective on-off-on fluorescent probe for selective and sensitive detection of Cr(VI) and sulfites with detection limit 0.01 μmol/L and 0.35 μmol/L, respectively. It is found that mechanism of fluorescence quenching of the as-prepared C-dots by Cr(VI) can be mainly attributed to a kind of electron exchange quenching.