An AIE active probe for specific sensing of Hg2+ based on linear conjugated bis-Schiff base

[Display omitted] •α-Cyanostilbene-functionalized linear bis-Schiff base 4 exhibits AIE character.•4 exhibits sensitive and selective fluorescence turn-on response towards Hg2+.•4 can be used for discrimination Hg2+ by “naked eye” or using UV lamp.•4 can detect trace Hg2+ in organic solvent, water environment and living cells. A novel aggregation-induced emission (AIE) active linear conjugated bis-Schiff base compound, (E)-N,N′-bis(4-(Z)-2-(4-butoxyphenyl)-1-cyanovinylphenyl)-1,4-benzenebismethaneimine (4) containing α-cyanostilbene unit was designed, synthesized and characterized. The distinct change of color and/or fluorescence emission of 4+Hg2+ in tetrahydrofuran (THF) and THF/water solution provided a simple and easy discrimination way for Hg2+ by “naked eye” or using a UV lamp. The aggregating patterns of 4 were applied to explain the mechanism of sensing. The as-synthesized sample showed comparatively high selectivity and sensitivity to Hg2+ through fluorescence “turn-on” response with a low detection limit (3.4×10−9M in THF, 2.4×10−7M in THF/water). The results implied that the as-made sample could effectively act as Hg2+ sensor not only in THF and THF/water but in living cells.