Self-Assembly of Eu³⁺ Complexes Enabling Multistimuli-Responsive Data Encryption

Multistimuli-responsive luminescent materials are pivotal for next-generation information encryption, yet integrating orthogonal stimuli-responsiveness, high reversibility, and nanoscale programmability remains a formidable challenge. Herein, Eu³⁺-based nanoparticles (Eu-NPs) are constructed with triply orthogonal stimuli-responsive luminescence (pH/thermal/light) through J-aggregation-driven self-assembly of a tailored β-diketone complex (Eu(THA)₃). Spatial confinement within the nanostructure suppresses non-radiative decay, enhancing the luminescence quantum yield while extending the lifetime. Crucially, the Eu-NPs enable: i) Reversible pH-switching between red Eu³⁺ emission (614 nm) and green ligand AIE (480 nm) with good cyclability; ii) Linear thermal quenching for dual-mode thermometry (intensity sensitivity: 3.82%·K^-1; lifetime sensitivity: 7.46%·K^-1); iii) UV/Vis-light-modulated FRET with dithienylethene (DTE) enabling single-particle ON/OFF switching. Leveraging these properties, hierarchical encryption platforms are developed, including dynamically responsive printed labels, QR codes, and hydrogels. Furthermore, exploiting inherent assembly randomness, physically unclonable functions (PUFs) are fabricated with dual-key (intensity/lifetime) authentication and ultrahigh encoding capacity (4^1,600). This strategy establishes a new paradigm for adaptive anti-counterfeiting by integrating dynamic data encryption with physically unclonable security in a single rare-earth nanoplatform.