Multi-Channel Anti-Counterfeiting Labels via Guided Chiral Au Nanoparticle Arrays Derived from Self-Assembled Block Copolymers

Abstract

Large-scale counterfeit operations have emerged as a significant global concern, possibly leading to substantial economic losses and severe threats to the safety of society. Considerable research efforts have been devoted to plasmonic and optical anticounterfeiting technologies, aiming at distinguishing counterfeit labels for straightforward, rapid identification. Herein, we present multichannel anticounterfeiting labels featuring directional, plasmonic, and chiroptical properties, characterized by grazing-incidence small-angle X-ray scattering, Raman spectral shifts, and circular dichroism, respectively. Multichannel anticounterfeiting labels incorporating guided chiral Au nanoparticles were fabricated via the directed self-assembly of polystyrene-block-poly(methyl methacrylate) block copolymers in conjunction with nanoimprint lithography. Unique chiroptical properties induced by photodeposition under circularly polarized light were integrated with directional information and pronounced plasmonic responses, yielding a trimodal signature suitable for high-security anticounterfeiting applications. Our multichannel anticounterfeiting approach presents a platform for information encryption with significantly enhanced data security.