Lanthanide-based stimulus-responsive supramolecular fluorescent materials for information storage and time-dependent information encryption

Developing storage media that meets the needs of different information storage scenarios is difficult. This manuscript presents a strategy to achieve time-resolved encryption based on a supramolecular ternary complex. These supramolecular systems are prepared via noncovalent interactions between cholesterol, spiropyran, and lanthanide ions, which display outstanding photochromic properties, including fast response, a high conversion rate, and the capacity to tune fluorescence. Because of the peculiar supramolecular ternary complex, the material displays tunable dynamic fluorescence emission change from green to yellow to red via the fluorescence resonance energy transfer (FRET) process coupled with more irradiation time. More importantly, photochromic properties can be adjusted by altering the amount of cholesterol and spiropyran ligands in solvents or solid phases, thereby providing fine and adjustable time-related features for materials. This allows confidential processing and construction of additional information data via time-resolved multidimensional encryption and dynamic anti-counterfeiting. In this study, we developed a novel time-dependent information encryption, similar to opening a lock requiring two necessary keys. One of these keys is the "time factor," which serves as a dynamic key with many unpredictable possibilities, which renders imitation and decryption more challenging.