An effective dual sensor for Cu and Zn with long-wavelength fluorescence in aqueous media based on biphenylacrylonitrile Schiff-base.

Although some sensors for Cu and Zn had been reported, the sensor with long-wavelength emission in aqueous media for in-situ detecting Cu and Zn 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 Cu with quenched fluorescence and Zn with chromotropic fluorescence from red to yellow. The detection of Cu and Zn were realized without mutual interference in their coexistence system by means of the assistance of ATP. The detection limits were 2.3 × 10 M for Cu and 1.8 × 10 M for Zn, respectively. The sensing mechanism was elucidated by binding MS spectra, fluorescence Job's plot and H NMR spectra. Moreover, OPBS exhibited good bioimaging performance and the in-situ sensing abilities for Cu and Zn in living cells, suggesting the application potential for detecting Cu and Zn in both vitro assay and vivo environment.