<p>A novel Schiff base <b>SBA1</b>, was successfully synthesized and structurally characterized using UV-Vis, FTIR, and ¹H NMR spectroscopy. Its sensing capabilities were systematically investigated against a broad range of metal ions, including Cu²⁺, Co²⁺, Zn²⁺, Pb²⁺, Ag⁺, Cd²⁺, Mg²⁺, Ni²⁺, Ca²⁺, Fe³⁺, Mn²⁺, Hg²⁺, K⁺, and Na⁺. Among these, <b>SBA1</b> exhibited a highly selective and distinct colorimetric response toward Cu²⁺ ions, marked by a visible color change from yellow to colorless. Fluorescence studies further revealed a substantial enhancement in emission intensity upon Cu²⁺ binding, indicating strong interaction and excellent sensing performance. The sensor demonstrated impressive sensitivity, achieving a limit of detection (LOD) of 0.0031 ppm (0.049 µM) and a limit of quantification (LOQ) of 0.0096 ppm, enabling trace-level detection of Cu²⁺ ions in aqueous media. To evaluate its practical utility, the <b>SBA1</b> was tested in real environmental samples, including soil-extracted water, drinking water, lake water, river water, and pond water. Fluorescence titration with Cu²⁺-spiked samples showed outstanding recovery rates ranging from 91.0% to 102.0%, confirming the sensor reliability and accuracy in complex matrices. In addition to its sensing capabilities, the antibacterial potential of <b>SBA1</b> was also assessed against selected bacterial strains. The compound exhibited notable antibacterial activity, indicating its dual functionality as both a highly sensitive Cu²⁺ sensor and an effective antimicrobial agent. These findings position <b>SBA1</b> as a promising multifunctional material for environmental monitoring and biomedical applications.</p>