Novel highly selective and sensitive fluorescent sensor for copper detection based on N-acylhydrazone acridone derivative

Abstract

A new N-acylhydrazone based on acridone (S1) was synthesized by Schiff base condensation of 2-(9-oxoacridin-10-yl)acetohydrazide and salicylaldehyde and studied as selective fluorescence turn-off sensing towards Cu2+ ions in aqueous media. S1 demonstrated fluorescence turn-off sensing towards Cu2+ ions. Conversely, the metal ions K+, Mg2+, Zn2+, Fe2+, Al3+, Pb2+, Cr2+, Cd2+, Ag+, Fe3+, Ba2+, Hg2+, Mn2+, Co2+, and Ni2+ produced only minor decrease in the fluorescence of the system. The binding ratio of S1–Cu2+ complex was determined from the Job plot to be 1:2. Moreover, the S1–Cu2+ complex showed good fluorescence turn-off in presence of different counter ions of copper. In addition, the detection limit of S1 towards Cu2+ ions is 0.80 μM, which is enough for sensing the Cu2+ in the biological system and water within the U.S Environmental Protection Agency limit (∼20 μM).