Dual-Action innovation: schiff base for trace Cu2+ ions detection and powerful antibacterial potential

Abstract

A novel Schiff base SBA1, 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, SBA1 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 SBA1 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 SBA1 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 SBA1 as a promising multifunctional material for environmental monitoring and biomedical applications.