Chiral Cryptographic Key-Based Fluorescence Encryption Enabled by Stimuli-Responsive Metal–Organic Frameworks

Increasing threats of data forgery breaches necessitate the development of advanced encryption strategies beyond traditional cryptographic methods. Fluorescence encryption has emerged as a promising alternative, yet current systems suffer from low security due to simple, reversible stimuli responses. Here, we introduce a novel lock-and-key encryption system using a chiral cyclodextrin metal–organic framework (CDMOF), termed Zole@CDMOF (Zole = acetylated benzoimidazole), for enantioselective discrimination of phenylethylamine (PEA) enantiomers.Confined Zole serves as the lock, while PEA enantiomers act as the key, selectively triggering fluorescence turn-on via acetyl─O bond cleavage and restoring excited-state intramolecular proton transfer (ESIPT) of deacetylated Zole. Mechanistic studies reveal that enantioselectivity arises from thermodynamic differences and distinct hydrogen-bonding interactions between PEA enantiomers. To enhance practical application, Zole@CDMOF is fabricated into a flexible sensor via scotch tape strategy, enabling visual indexing of enantiomeric excess. Additionally, we propose a barcode chiral encryption model, establishing a quadruply encrypted system with ultra-high security—allowing only one out of approximately two million keys to decrypt. This study pioneers the first chiral cryptographic key in fluorescence encryption, paving the way for ultra-secure encryption, advanced chiral sensing, and stimuli-responsive materials.