Chiral Azobenzene‐Based Ultrathin Peptoidoplatelets Enabling Circularly Polarized Luminescence Switches for Multilevel Information Encryption

ABSTRACT Stimuli‐responsive circularly polarized luminescence (CPL)‐active materials are critical for advanced security systems due to their unique chiroptical signatures in enhancing anti‐counterfeiting dimensionalities. However, inefficient coupling of stimulus response to chiroptical output, together with the difficulty in achieving high dissymmetry factors ( g lum ), poses challenges for visualized encryption applications. Herein, we established a molecular engineering paradigm for dynamically photo‐responsive chiroptical materials through the self‐assembly of sequence‐defined alternating amphiphilic chiral azopeptoids ( S/R ‐AACAPs). Pendant hydrophobic conjugate stacking mechanism accounted for the successive generation of ultrathin 2D achiral peptoidoplatelets (∼2.3 nm). Subsequent trans‐ to ‐cis photoisomerization of azobenzenes was beneficial to trigger efficient chirality transfer and amplify, consequently driving a photo‐modulated reversible structural transition to ultrathin helical nanobelts (∼20 nm pitch). Such light‐switchable and recyclable chirality transfer induced CPL modulations after conjugation of S/R ‐AACAPs with fluorescein fluorophore. Notably, encapsulation of these chiral aggregates into a hydrogel matrix dramatically rose the g lum value to 0.1 (two‐orders‐of‐magnitude larger than the relative aqueous solution) due to the chirality coupling and imprinting effects, conveying multilevel encryption information with spatially resolved cryptographic patterns. This sequence‐defined peptoids engineering synergistically fuses light‐responsivity with supramolecular chirality transfer and CPL optical property, opening prospective avenues for responsive photonic devices and adaptive security platforms.