A novel multifunctional fluorescent sensor based on N/S co-doped carbon dots for detecting Cr (VI) and toluene

Abstract

The construction of a novel multifunctional fluorescence platform is of great significance to detect different toxic pollutions. In this work, multifunctional nitrogen and sulfur doped fluorescence carbon dots (N, S-CDs) were synthesized with citric acid monohydrate and thiosemicarbazide as raw materials. The quantum yield (QY) of N, S-CDs was calculated as 12%. The fluorescence intensity of N, S-CDs could be quenched obviously by Cr (VI) due to the inner filter effect, achieving a low detection limit of 0.33 nM for Cr (VI). While excessive Ba2+ was added, the fluorescence intensity could be restored. Meanwhile, based on the fact that the fluorescence of the N, S-CDs could be enhanced by toluene, the detection of toluene was achieved and the detection limit was low as 0.03 μM. Furthermore, the practical application of the N, S-CDs was assessed in the river water. The proposed N, S-CDs could provide a promising fluorescence platform for detecting different toxic pollutions.