An effective dual sensor for Cu2+ and Zn2+ with long-wavelength fluorescence in aqueous media based on biphenylacrylonitrile Schiff-base

Although some sensors for Cu2+ and Zn2+ had been reported, the sensor with long-wavelength emission in aqueous media for in-situ detecting Cu2+ and Zn2+ was always expected. Herein, a biphenylacrylonitrile Schiff-base (OPBS) with large aromatic conjugated system was designed and synthesized in yield of 82%. OPBS possessed excellent long-wavelength fluorescence at 550-750 nm in aqueous media, which selectively response to sense Cu2+ with quenched fluorescence and Zn2+ with chromotropic fluorescence from red to yellow. The detection of Cu2+ and Zn2+ were realized without mutual interference in their coexistence system by means of the assistance of ATP. The detection limits were 2.3 x 10(-7) M for Cu2+ and 1.8 x 10(-6) M for Zn2+, respectively. The sensing mechanism was elucidated by binding MS spectra, fluorescence Job's plot and H-1 NMR spectra. Moreover, OPBS exhibited good bioimaging performance and the in-situ sensing abilities for Cu2+ and Zn2+ in living cells, suggesting the application potential for detecting Cu2+ and Zn2+ in both vitro assay and vivo environment. (C) 2021 Elsevier B.V. All rights reserved.