A simple benzildihydrazone derived colorimetric and fluorescent 'on-off-on' sensor for sequential detection of copper(II) and cyanide ions in aqueous solution

Herein, we have developed a simple, environment friendly fluorescent turn-off and colorimetric sensor for the rapid detection of Cu7' ions in aqueous solution by using organic Schiff base ligand benzildihydrazoneN,IT-bis(2-hydroxy-4-diethylamino-1 -formy /benzene)(L). Binding interaction between Land various metal ions was established by UV-vis and fluorescent measurements showing favourable coordination towards Cu7+ and almost no interference with the other metal ions, i.e., Na+, Ba7+, Fe3+, Co7+, Ni7+, Zn7+, Cd7+, Ca7+, He+, Pb7+,Cr3+, Ag* and Al3+. L exhibited binding-induced colour change from yellow to light red. The obtained L-Cu7+ complex could be used as a new cascade sensor for detecting cyanide anion (CN-). The corresponding detection limits were found to be 7.3 x 10(-10) M for Cu7+ (lowest ever known in the family of fluorescent colorimetric Schiff base chemo-sensor) and 1.5 x 10(-7) M for CN-1. To further assess the analytical performance of this sensing system, the concentrations of Cu7+ and CN-1 ions were determined in real water samples and simulated urine sample. (C) 2017 Elsevier B.V. All rights reserved.