Spatially Decoupled Fluorescent Amphiphiles for pH-Controlled Anion Detection in Water

Recognition of anions in water remains a key challenge in supramolecular chemistry. We report pH-switchable multipodal amphiphiles that detect hydrophobic anions in aqueous media by a fluorescence turn-on response. An alternating arrangement of fluorogenic cationic heads and pH-responsive aliphatic tails around a benzene core regulates ion pairing and aggregation within sharply defined pH windows. This spatial and functional decoupling allows anion recognition and pH responsiveness to operate independently yet cooperatively.