sensitive and selective probe for visual detection of Cu2+ based on 1, 8-naphthalimidederivative

A novel 1, 8-naphthalimide-based derivative, named as (E)-6-(2-((1H pyrrol-2-yl)methylene)hydrazinyl)-2-(2-hydroxyethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (HHBD), was synthesized via facile condensation and substitution reactions. It showed high sensitivity and selectivity to Cu2+ in CH3CN-H2O (v/v = 3:7, pH = 7.0) solution, and the hypsochromic shift of the absorption band & the enhancement of the fluorescence emission intensity were distinct for the detection of Cu2+ even in the presence of other competitive metal ions, such as Ag+, Al3+, Ca2+, Co2+, Cr3+, Fe2+, Fe3+, K+, Li+, Mg2+, Na+, Ni3+, Zn2+. The binding stoichiometry between HHBD and Cue* was calculated from Job's plot and the complexation mechanism was explored by H-1 NMR and FTIR spectrophotometry. Furthermore, HHBD binding capability with Cu2+ was further demonstrated using DFT calculations. The probe was applied successfully in real water samples assay. Strip papers were also designed and used to detect various concentrations of Cu2+ aqueous solution, whose color change showed their potential application for on-site detection of Cu2+ in pollution water. (C) 2018 Elsevier B.V. All rights reserved.