Natural Rutin‐Based AIE Probes With Enhanced Fe³⁺ Recognition via Hydroxyl Group Engineering

Traditional fluorescent probes have challenges, including aggregation‐induced quenching, biological incompatibility, and suboptimal selectivity. In this study, we developed a novel probe derived from natural rutin featuring an aggregation‐induced emission (AIE) effect. Through hydroxy engineering of rutin, the optimized probe enables precise detection of Fe 3+ via 2:1 stoichiometric coordination. The probe demonstrates remarkable analytical performance, with a detection limit as low as 0.22 μM. Concentration‐dependent responses were observed within 0–20 μM, with significant linearity ( R 2 > 0.99) in the 0–10 μM range. Density functional theory calculations reveal that the binding of Fe 3+ effectively suppresses intramolecular charge transfer. The hydroxy‐engineered modification plays a pivotal role in facilitating complexation for bond formation and providing appropriate steric hindrance. This research establishes a new benchmark for natural product‐based AIE probes and deepens understanding of the structure–activity relationships governing flavonoid‐metal recognition.