Ionic Liquid-based low-dimensional Fluorosensor for Ultrasensitive Detection of Perchlorate ions in Aqueous Media

Abstract

An anthracene-coupled phenanthroimidazolate-based ionic liquid (APIL) is synthesized and processed via reprecipitation to yield its microstructured form (mAPIL). Structural and morphological characterizations were performed using spectroscopic and microscopic techniques. Neat APIL dippalys bright green yellow photoluminosity under the exposure of a 365 nm UV light and utilized as a fluorescent security ink under solvent-free conditions. In aqueous suspension, mAPIL displays weak fluorescence, which is significantly enhanced upon exposure to ClO₄⁻ ions, driven by ion-induced molecular clustering, enabling sensitive detection with a limit of detection (LOD) of 12.7 nM, substantially below the regulatory limit established by the EPA for drinking water. A portable detection kit was fabricated for real-world application, and performance validation using spiked environmental samples confirmed the system's practical utility. The present work demonstrates a promising strategy for the design of ionic liquidsderived nano fluorosensors for ecological monitoring of hazardous ions, perchlorate.