Tunable Spin‐Polarized Chiral Plasmonic Films for Dual‐Mode Enantiomer Recognition

Chirality‐induced spin selectivity (CISS) has emerged as a frontier research direction in chiral recognition. However, existing CISS‐based sensing platforms are often constrained by structural disorder, limited spin selectivity, and insufficient electrical conductivity, which restrict their practical application in high‐performance chiral sensing. Inspired by the coherent potential fields generated through the hierarchical and ordered assembly of biomacromolecules, which enable efficient long‐range spin transport, we constructed chiral gold superlattice nanofilms (CANFs) through the precise self‐assembly of chiral gold nanoparticles. The CANFs achieved a spin polarization efficiency of up to +94.17% ± 3.72%. Benefiting from their excellent electrical conductivity and spatial‐confinement‐enhanced signal amplification, the CANFs enable dual‐mode enantioselective recognition of kynurenine enantiomers, with a photo‐driven ionic‐current discrimination ratio as high as 10.3. The platform further exhibits outstanding analytical performance, including low limits of detection of 0.024 nM in the photo‐driven mode and 0.012 µM in the electrochemical mode, broad linear response ranges, and good applicability in complex clinical matrices. By integrating CISS‐mediated spin‐polarized transport with nanoconfinement‐enhanced signal transduction, this work establishes a versatile strategy for developing next‐generation real time, high‐performance chiral sensing platforms.