Biomimetic Thermoresponsive Nanoassemblies With Three‐Step Energy Funneling for Switchable ROS Generation and Photocatalysis

Mimicking the adaptive light‐energy management of natural photosynthetic systems remains challenging, particularly in aqueous media where efficient multistep energy transfer and environmental responsiveness are rarely integrated within a single nanoscale architecture. Herein, we report thermoresponsive biomimetic supramolecular nanoassemblies featuring three‐step cascade Förster resonance energy transfer, constructed by coassembly of a minimalist amphiphilic aggregation‐induced emission luminogen (TPEG) with eosin Y (ESY), Nile Red (NiR), and chlorin e6 (Ce6). The resulting hierarchical nanoassemblies enable efficient directional energy funneling and enhanced generation of reactive oxygen species (ROS), including 1 O 2 and O 2 •− . Consequently, the harvested excitation energy is effectively converted into photochemical activity, promoting aerobic oxidative amidation and benzimidazole synthesis in water with yields up to 91% and 92%, respectively. Moreover, the lower critical solution temperature transition of the oligo(ethylene glycol) corona of TPEG provides a reversible mechanism for regulating supramolecular organization, energy flow, ROS generation, and photocatalytic activity, enabling thermally switchable photochemical outputs. This work establishes a biomimetic strategy for thermally adaptive light‐energy management and controllable light‐energy conversion, providing new opportunities for responsive artificial light‐harvesting systems and functional supramolecular nanomaterials.