Dynamically Securing the Data by 1O2 Sensitization of Fluorescent Composites with a High Latency and Uncrackable Features

Comprehensive Summary Dynamic fluorescent materials play a crucial role in secure inks for data encryption; however, they are still plagued by issues such as photodegradation, poor latency, and susceptibility to unauthorized access. Herein, we propose a photochemically modulated dynamic fluorescent encryption system based on 1 O 2 sensitization of fluorescent composites, comprising a 1 O 2 ‐sensitive fluorophore (F2) and non‐emissive polymers. After UV irradiation, in‐situ generated 1 O 2 from the polymer effectively binds with F2 to form endoperoxides (F2EPO), resulting in a significant redshift in emission, up to 150 nm. The 1 O 2 concentration is closely related to the irradiation time, rendering different fluorescent colors in a time‐gated fashion. Moreover, the emission of F2EPO can be regulated by polymer chemical structure, molecular weight, and crosslinking density. Relying on these merits, we develop a dynamic data encryption method with various non‐emissive polymers as the data storage media, UV light irradiation as the data encoder, and F2 as the data decoder. UV light irradiation of diverse polymer solutions generates 1 O 2 at different concentrations, effectively encoding the data, which remains invisible under both UV and natural lights. The addition of F2 to these irradiated polymer solutions produces different redshifted fluorescence, enabling secure data decryption. Attributing to the non‐emissive nature of the polymers, time‐gated readout fashion, excellent latency of 1 O 2 , and subtle interactions between 1 O 2 and F2, this data encryption is nearly undecipherable. This work offers an advantage data encryption approach beyond the reach of conventional fluorophores.