Metal Coordination-Induced Structural Regulation of Twisted Cucurbit[14]uril-Based Supramolecular Assemblies for Mercury Ions Detection on Smart Platform

The high selectivity and reversibility of metal coordination enable precise modulation of the structural morphology of supramolecular assemblies, which is essential for the development and intelligent application of functionalized materials. In this study, sheet-like supramolecular assemblies (Pyr-O@<i>t</i>Q[14]) constructed by twisted cucurbit[14]urils (<i>t</i>Q[14]) and pyrene derivatives (Pyr-O) through host-guest interactions, which exhibit excellent optical properties, achieves highly sensitive detection of Hg²⁺ by fluorescence quenching, with a limit of detection of 0.177 μM. A novel smart platform, compatible with smartphones, is developed to enhance the detection efficiency and practicality for practical applications. From a microscopic structural perspective, adjusting the concentration of Hg²⁺ can change the structural morphology of Pyr-O@<i>t</i>Q[14] from lamellar to square and finally to spherical, demonstrating the dynamic control of the assembly structure in response to environmental stimuli. This study not only presents a novel and efficient intelligent quantitative sensing platform for Hg²⁺ detection but also highlights the unique advantages of <i>t</i>Q[14] in constructing supramolecular assemblies with tunable, responsive structures, opening new avenues for the design and synthesis of advanced smart materials.