A specific fluorescence probe for chromium (VI) anions and its application

A facile fluorescent receptor for Cr(VI) anions was designed and prepared by 9-ethyl-9H-carbazole-3,6-dicarbaldehyde and 2-aminobenzenethiol. The interactions of the receptor with various anions were investigated through UV-vis absorption and fluorescence emission spectra, respectively. Experimental results revealed that the receptor could recognize Cr(VI) anions with high selectivity and sensitivity in H2O/DMSO mixed medium. A fluorescence on-off signal of the receptor to Cr(VI) anions was observed and verified by H-1 NMR and density functional theory (OFT). The detection limit of the receptor for Cr(VI) may be up to 10(-7) mol/L. Additionally, the receptor as a fluorescent probe can be used to detect the content of Cr(VI) anions in milks, and displayed good accuracy and sensitivity. The work provides a new strategy for detecting Cr(VI) and developing the application in practical samples and systems. (C) 2017 Elsevier B.V. All rights reserved.