Highly Water-Dispersible Spiropyran-Octapeptide Supramolecules: Efficient, Multi-processable, and Versatile Photoswitches for Time-Dependent Dual-Mode Encryption

With exceptional photochromic and photoluminescent properties, spiropyrans have demonstrated significant potential for advanced information encryption and anti-counterfeiting applications. However, its inherent water insolubility leads to incompatibility with aqueous polymers, and even more, its ease of leaching from the matrix hinders the formation of stable stimuli-responsive platforms through direct blending with all polymers. Here, the fabrication of amphiphilic spiropyran-octapeptide molecules is reported that can spontaneously self-assemble into highly water-dispersible supramolecular nanofibers in water. These assemblies exhibit universal polymer matrix compatibility while retaining the rapid photo-responsiveness of spiropyrans. The formation of strong interactions between the supramolecular assembly and polymer chains ensures the long-term stability of the resultant stimuli-responsive materials in aqueous environments. These platforms fully preserve the base polymers’ processing properties, with silk fibroin as the matrix offering exceptional opportunities for constructing photo-responsive platforms in various forms (e.g., films, gels, fibers, and coatings) with multiple functionalities using diverse solution processing techniques. Integrating distinct photochromic and photoluminescent responses within a single format without interference, combined with environmental stability and processing flexibility, enables the creation of dual-mode, high-security encryption devices for diverse application scenarios. The outlined strategy provides innovative concepts for developing high-performance, versatile intelligent systems utilizing stimulus-responsive molecules.