Design and Construction of an Artificial Light‐Harvesting System Based on Polyacrylic Acid and a Cyanostilbene Derivative

The development of materials with tunable fluorescence properties is critical for advancing applications in sensing, imaging, and information encryption. In this study, we synthesized a cyanostilbene derivative (CSA) that combines the benefits of aggregation‐induced emission (AIE) and self‐assembly in water. CSA, featuring a cyanostilbene core and hydrophilic carboxylate groups, exhibits weak fluorescence in solution but forms highly fluorescent nanoaggregates (CSA‐PAA) upon self‐assembly with polyacrylic acid (PAA). By integrating rhodamine 6G (Rh6G) as an energy acceptor, we constructed a light‐harvesting system (CSA‐PAA‐Rh6G) with high Förster resonance energy transfer (FRET) efficiency and tunable emission from green to yellow. This work presents a facile approach for the development of aqueous light‐harvesting systems and shows promise for future applications in tunable luminescent materials. An aggregation‐induced emission molecule (CSA) derived from cyanostilbene dicarboxylate was designed and synthesized. It shows weak emission in water but strong emission upon self‐assembly with polyacrylic acid (PAA). By further co‐assembly with Rh6G, an efficient light‐harvesting system with tunable emission was constructed.