Chiral CDs-based fluorescence sensor for rapid and specific sensing K4[Fe(CN)6] in table salt and salted food.

Potassium ferricyanide (K 4 [Fe(CN) 6 ]) as anti-caking agent plays an important role in avoiding the formation of chunks for fine particulate solids. However, inappropriate and excessive addition and decomposition of K 4 [Fe(CN) 6 ] are detrimental to physical health. At present, appropriate strategies for convenient and accurate analysis of K 4 [Fe(CN) 6 ] in table salt and pickled food are desirable. Herein, an efficient "ON-OFF-ON" fluorescent sensor based on chiral carbon dots was prepared by a simple one-step hydrothermal method. The chiral CDs with L-Tryptophan and D-Tryptophan as chiral source were named as L-CDs and D-CDs. Notably, the bright fluorescence of L/D-CDs could be effectively quenched by K 4 [Fe(CN) 6 ] through dynamic quenching mechanism. This fluorescent sensor achieved excellent sensitive and selective detection of K 4 [Fe(CN) 6 ] with a limit of detection (LOD) of 25.0 ng·mL−1. In addition, the L/D-CDs could be applied not only for selective fluorescent recognition of K 4 [Fe(CN) 6 ] by the methods of portable filter paper and hydrogels, but also as fluorescent dye for repeated message encryption and decryption. [Display omitted] • An efficient "ON-OFF-ON" fluorescent sensor based on chiral carbon dots was prepared. • This method has high sensitivity and excellent selectivity for detecting K 4 [Fe(CN) 6 ]. • The detection limit is much lower than those of other methods. • The L-CDs have been successfully applied to solid state sensors and multiple information encryption. Potassium ferricyanide (K 4 [Fe(CN) 6 ]) as anti-caking agent plays an important role in avoiding the formation of chunks for fine particulate solids. However, inappropriate and excessive addition and decomposition of K 4 [Fe(CN) 6 ] are detrimental to physical health. At present, appropriate strategies for convenient and accurate analysis of K 4 [Fe(CN) 6 ] in table salt and pickled food are desirable. Herein, an efficient "ON-OFF-ON" fluorescent sensor based on chiral carbon dots was prepared by a simple one-step hydrothermal method. The chiral CDs with L-Tryptophan and D-Tryptophan as chiral source were named as L-CDs and D-CDs. Notably, the bright fluorescence of L/D-CDs could be effectively quenched by K 4 [Fe(CN) 6 ] through dynamic quenching mechanism. This fluorescent sensor achieved excellent sensitive and selective detection of K 4 [Fe(CN) 6 ] with a limit of detection (LOD) of 25.0 ng·mL−1. In addition, the L/D-CDs could be applied not only for selective fluorescent recognition of K 4 [Fe(CN) 6 ] by the methods of portable filter paper and hydrogels, but also as fluorescent dye for repeated message encryption and decryption. [ABSTRACT FROM AUTHOR]