Investigation on Dye Embedded MOF Composite for Ratiometric Sensing of epNACs From Water Medium

ABSTRACT Nitro‐explosives represent a substantial portion of chemical pollutants prevalent in industrial area water sources. Consequently, achieving sensitive detection of these hazardous organic pollutants poses a significant challenge in ensuring the public health and environmental sustainability. In addressing the requirement of quantitative detection of TNP like explosives nitro‐aromatic compound, a robust sensory probes RhD@Zn‐MOF rationally designed and developed. The in situ incorporation of the fluorescent dye Rhodamine 6G (RhD) into the framework of Zn‐MOF constituting 1,4‐benzenedicarboxylic acid (BDC) and triethylenediamine (TEDA) resulting in generation of two decisively distinguishable emission peaks. This evidently introducing a new emission peak at 540 nm associated to the interaction between Zn‐MOF and RhD dye in a water solution that coexisted with the characteristic peak of Zn‐MOF at 425 nm. Further, the RhD@Zn‐MOF demonstrated a distinctive response to TNP, altering both dye and building block–based fluorescence intensities compared to other analytes. The variation in the intensity ratio of these two‐emission band decisively possesses concentration‐dependent quantitative response selectivity towards TNP. This further lead to ratiometric change in the colour of optical fluorescence response encountered upon introduction of different concentration of TNP. This ratiometric change in the fluorescence colour is easily observable to the naked eye, indicating the practical utility of such type of duel‐emitting sensory probes. The exceptional photostability across a broad pH range highlighted the applicability of this luminescent probe for selective TNP detection in aqueous environments.