Selective Detection of 2, 4-DNT Using Sulfonyl Chloride-Appended Oxacalix[4]arene: Synthesis, Spectroscopic Analysis and Biological Evaluation

We designed and synthesized a novel sulfonyl chloride-substituted oxacalixarene (DCOC) as a highly selective fluorescent sensor for the detection of 2,4-dinitrotoluene (2,4-DNT). The structural integrity of DCOC was confirmed using ^1H-NMR, ^13C-NMR, and FT-IR spectroscopy. Fluorescence studies demonstrated a pronounced quenching effect upon interaction with 2,4-DNT, with negligible response to other nitroaromatic compounds, confirming high selectivity. The probe exhibited a detection limit as low as 5 µM. Computational investigations, including DFT calculations and HOMO–LUMO analysis, supported the stability and binding behaviour of the DCOC–DNT complex. Molecular docking and 100 ns molecular dynamics simulations with PARP-1 protein further validated the stable interaction profile. The cytotoxic potential of DCOC was evaluated via MTT assay on MCF-7 breast cancer cells, revealing moderate cytotoxicity with an IC₅₀ value of 417.76 ± 1.77 µM. These findings establish DCOC as a promising supramolecular sensor for the selective detection of 2,4-DNT in environmental and forensic contexts.