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Novel anthracene-based Schiff base derivative (4-(anthracen-9-ylmethylene) amino)-5-phenyl-4H-1,2,4-triazole-3-thiol; <b>AT2</b>) is synthesized and utilized as an aggregation-induced emission-enhancement (AIEE) active probe to detect Zn²⁺ and Tyrosine. Ultraviolet-visible absorption/photoluminescence (UV-vis/PL) spectroscopy studies on the AIEE property of <b>AT2</b> (in ethanol) with increasing water fractions (<i>f_w</i>: 0–97.5%) confirm the <i>J</i>-type aggregation. Excellent sensor selectivity of <b>AT2</b> to Zn²⁺ and its reversibility with Tyrosine are demonstrated with PL interrogations. 2:1 and 1:1 stoichiometry and binding sites of <b>AT2</b>-Zn²⁺ and Tyrosine-Zn²⁺ complexes are elucidated from Job plots, HR-mass, and ¹H-NMR results. Nanomolar-level detection limits (LODs) of Zn²⁺ (179 nM) and Tyrosine (667 nM) and association constants (K_as) of 2.28 × 10⁻⁶ M⁻² (for <b>AT2</b>-Zn²⁺) and 1.39 × 10⁻⁷ M⁻¹ (for Tyrosine-Zn²⁺) are determined from standard deviation and linear fittings. Nanofiber formation in AIEE and aggregated/dispersed nanoparticles in the presence of the Zn²⁺/Tyrosine are supported by scanning-electron microscope (SEM), transmission-electron microscope (TEM), atomic-force microscope (AFM), and dynamic-light scattering (DLS) investigations. Density-functional theory (DFT) studies confirm an “On-Off” twisted intramolecular charge transfer/photo-induced electron transfer (TICT/PET) and “On-Off-On” PET mechanisms for AIEE and sensors, respectively. B16-F10 cellular and zebrafish imaging are conducted to support the applications of AIEE and sensors.