Time‐Encoded Information Encryption with pH Clock Guided Broad‐Spectrum Emission by Dynamic Assemblies

Abstract With growing threats from counterfeiting‐based security breaches, multi‐level and specific stimuli‐responsive anti‐counterfeiting devices and message encryption methods have attracted immense research interest. Fluorescence‐based encryption from aggregation‐induced emission (AIE)‐based materials solves the problems to a considerable extent. However, the development of smarter patterns with hierarchical security levels alongside dynamic display is still challenging. To screen out this complication, we bring forward a pH‐switchable fluorescent assembly of an AIEgen and an aliphatic acid. We later temporally direct the molecular assembly with the aid of a chemical trigger‐regulated pH clock, generating a transitory multicolor emission, including transient white light generation. The pH‐dependent emissions were further implemented in constructing smart multi‐input fluorescent chemical AND gates. Subsequently, we integrate the time‐gated emissive system to develop an advanced multi‐dimensionally secure data encryption strategy. This novel approach enhances anti‐counterfeiting measures by introducing an additional layer of security based on temporal characteristics.