Tetrazole-based fluorescent probe for sensitive detection of Cu2+: photoluminescence, biological activity, DNA/BSA interaction, and theoretical insights

Tetrazoles (TZs), a unique class of nitrogen-rich heterocycles, possess a versatile aromatic ring structure capable of strong coordination with metal ions. In this work, we investigate the chemosensory, biological, and computational characteristics of 1,4-Di(tetrazole-5-yl)butane ( DTB ), a tetrazole-based fluorescent probe. Fluorescence spectroscopy revealed that DTB exhibits pronounced sensitivity and selectivity toward copper ions, with a significant quenching effect on its photoluminescence (PL) intensity. Among a broad panel of tested metal ions, Cu 2+ showed the highest quenching efficiency, with an LOD of 3.03 × 10 −6 M, highlighting DTB 's potential as a high-performance Cu 2+ sensor for environmental and biological monitoring. In addition to its sensing capabilities, DTB 's biological activity was assessed via MTT cytotoxicity assay and fluorescence-based interaction studies with DNA and BSA. Molecular docking simulations supported these findings, providing insights into the binding modes and affinity. Furthermore, DFT insights were employed to predict the electronic structure and interaction mechanism of DTB with Cu 2+ , reinforcing the experimental observations. Overall, this multidisciplinary investigation establishes DTB as a promising multifunctional platform for metal ion detection and biointeraction analysis, bridging experimental and theoretical chemistry for advanced sensor development.