In this article, a novel triphenylamine-modified salicylaldehyde Schiff base 2-(((4-(diphenylamino)phenyl)imino)methyl)-4-(pyridine-4-yl)phenol (HL) was synthesized and structurally characterized. HL possessed D-π-A structure and exhibited typical AIE property in THF/H O. It was applied to selectively recognize Cu through an on-off mode in THF/H O (1/9, v/v), and the fluorescence attenuation was attributed to a paramagnetic quenching effect of Cu together with the abatement of HL aggregates. Hence, the detection limit achieved was as low as 1.32 × 10 M. The spectroscopic and ESI-HRMS results revealed a 1 : 2 complexation ratio of Cu with HL. The mechanism for sensing Cu was further confirmed by performing DFT calculations. Owing to the large affinity between Cu and His, the resultant CuL2 system was further used to detect His the off-on method based on the displacement of ligands. The detection limit for His reached 5.14 × 10 M. Furthermore, HL was available to prepare handy indicator papers for the on-site recognition of Cu and His. Confocal fluorescent imaging demonstrated that HL could sequentially respond to intracellular Cu and His.