A Quenched Fluorescence‐based Assay for Selective Detection of Nitroaromatic Compounds using Pyrene‐Appended Oxacalix[4]arene Host

Abstract

AbstractA novel pyrene appended supramolecular assembly (PAOC) has been fabricated by reacting intermediate‐pyren‐1‐ylmethyl 2‐chloroacetate (PMCA) with oxacalix[4]arene and characterized by 1H NMR, 13 C NMR and ESI‐Mass. PAOC works as fluorescent chemosensor for the selective detection of nitroaromatic compounds such as 4‐nitrophenol (4NP) and 2,4,6‐trinitrophenol (TNP). The binding mechanism between PAOC and the analytes were investigated through various spectroscopic techniques, and the results indicate a strong interaction between the two. The fluorescence intensity of PAOC is quenched upon interaction with nitroaromatic compounds due to a photoinduced electron transfer process, which was validated by DFT calculations. The sensor exhibits excellent selectivity and sensitivity towards TNP over other nitroaromatic compounds. The detection limits for TNP and 4NP were found to be 1.6 μM and 1.9 μM, respectively. PAOC's detection results in real water samples are remarkable. This study provides a new approach to develop highly selective and sensitive chemosensor for the detection of nitroaromatic compounds, which have significant environmental and health hazards.