Aggregation-Induced Emission and Selective Ion Sensing of Chiral 3D Polymer

A novel chiral three-dimensional conjugated polymer with aggregation-induced emission (AIE) was constructed via asymmetric Suzuki–Miyaura cross-coupling polymerization. Comprehensive photophysical characterizations confirmed its stable AIE activity, excitation-tunable luminescence, and solvatochromism in biomimetic media including water, simulated body fluid, and simulated urine. Ion sensing studies revealed that the chiral framework specifically chelates Ag⁺ through multiple coordination sites, producing significant fluorescence enhancement with a linear response from 0–900 μM and a micromolar detection limit, alongside excellent anti-interference capability. The material also exhibits differentiated dual-channel optical responses toward Fe³⁺ and Cr⁶⁺. Electrochemical analysis elucidated an electron-rich conjugated backbone, supporting a charge-transfer-mediated recognition mechanism. Benefiting from its unique multilayer three-dimensional cavity topology, the polymer demonstrates superior ion capture capacity and specificity over conventional linear or monolayer systems. This work presents a new molecular design strategy for high-performance fluorescent probes, with substantial practical potential for environmental and biological monitoring applications such as industrial wastewater treatment, surface water heavy-metal screening, and trace ion analysis in biological fluids.