Dynamic Chiral Plasmonic Systems‐Based on Spiropyran Derivatives and Gold Nanorods

Abstract Chiral plasmonic systems have gained significant interest due to their potential applications in advanced sensing, data storage, and optical devices. Here, it is demonstrated that photo‐ and thermoswitchability can be combined within a single chiral plasmonic composite. This approach enables the large‐scale organization of plasmonic nanoparticles without the need for complex fabrication techniques, offering a practical route toward the advanced design of chiral nanostructures. Spiropyran derivatives form twisted helical fibers through gelation in organic solvents, creating a chiral scaffold that induces chiral assembly of nanoparticles, leading to plasmonic circular dichroism. Detailed spectroscopic and microscopic analyses confirmed the structural organization of the helical fibers. Exposure to temperature reversibly disruptes the helical fibers and modulates their plasmonic properties, whereas UV illumination led to a gradual decrease in CD signal intensity. This dynamic system demonstrates that controlled fiber disentanglement and nanoparticle aggregation can be reversibly achieved in response to thermal stimuli, offering a versatile platform for next‐generation active chiral materials.