A green emitting phenanthroimidazolate anionic room temperature ionic liquid and its low-dimensional materials for...

Mercury is recognized as a hazardous heavy metal pollutant due to its bioaccumulative nature and high toxicity. Fluorescent ionic liquids (ILs) have emerged as promising sensing materials and have been successfully used to detect various target analytes. However, few studies have focused on real-time visual detection of trace mercury ions (Hg²⁺). The analysis and detection of mercury ions are of great significance for environmental and human health. To achieve real-time visual detection of Hg²⁺ ions while ignoring background interference matrices, we have synthesized a novel phenanthroimidazolate-based pyrene pendant ILs, [TTP]⁺[PDPI]^-, and studied its self-assembly behavior. The self-assembly of n[TTP]⁺[PDPI]^- has been utilized for the detection of Hg²⁺ ions. The electronegativity of the nitrogen atom in its imidazolate moiety was significantly enhanced within the ILs core, leading to a marked selective increase in its affinity for Hg²⁺ ions. Moreover, the sensor n[TTP]⁺[PDPI]^- has a low detection limit (in the nanomolar range, nM) and is highly responsive, making it suitable for a wide range of practical applications. The present report enables rapid, visual detection of Hg²⁺ ions, supporting the expanded use of ILs-based photonic materials for next-generation photoluminescent low-dimensional optodes in biomedical, diagnostic, environmental, and forensic applications.