Chiral Photoswitch with a Reversible Photofluorochromic Enhancement and Circularly Polarized Luminescence for Optical Encryption

Stimuli‐responsive circularly polarized luminescence (CPL) based chiral encryption systems are demonstrated potential in anticounterfeit applications ranging from daily life to advanced security domains. However, the efficient communication between responsive elements, structure transitions, and optical performances toward dynamically reconfigurable chiroptical signals still remains a significant challenge in responsive CPL systems. Benefiting from the highly modularized designability of peptoids, this study designed a programmable CPL platform through light‐driven structural reconfiguration of sequence‐defined amphiphilic alternating azopeptoids (AAAPs). Atomically‐precise synthesis enabled the optimize incorporation of azobenzene photoswitches and Rhodamine B with ( R/S )‐1‐naphthylamine units within tailored AAAPs, which self‐assembled into monodisperse peptoidosomes (323 nm diameter) with a vesicular thickness of ≈20.6 Å. Due to the UV‐triggered trans‐ to ‐cis isomerization of azobenzene units, the as‐produced superstructure experienced a reversible structural evolution from isotropic vesicles to anisotropic helical nanoribbons (81.6 nm width), where the corresponding chiroptical responses ( g abs = 6.9 × 10⁻⁴) are amplified and chiral fluorescence intensity are nearly enhanced twice via strong symmetry‐breaking and dispersion‐induced alleviation of quenching. This spatiotemporal modulation toward CPL‐based inks generated photo‐controllable anti‐counterfeiting patterns, enabling high‐contrast information concealment. The work establishes a prospective paradigm for adaptive chiral nanomaterials, offering transformative potential in anti‐counterfeiting technologies and reconfigurable photonic systems.