Engineered Chiroplasmonic Nanointerfaces Enable High‐Dissymmetry Circularly Polarized Electrochemiluminescence From Achiral Luminophores

ABSTRACT Circularly polarized electrochemiluminescence (CP‐ECL) provides an emerging route to encode chiral information into electrochemically generated light, but current strategies largely rely on intrinsically chiral luminophores, limiting molecular diversity, device integration, and dissymmetry‐factor amplification. Here, a strategy based on engineered chiroplasmonic nanointerfaces is developed for high‐dissymmetry CP‐ECL from achiral luminophores. In this design, luminophores are spatially confined around helicoid Au nanocrystals within a nanoscale plasmonic environment, and the resulting hybrid nanocrystals are assembled into monolayer films to couple chiroplasmonic near fields with electrochemically generated excited states. Using Ru(bpy) 3 2+ as a model achiral ECL luminophore, the helicoid Au@SiO 2 ‐Ru nanocrystal monolayer electrode produces mirror‐image CP‐ECL responses with a high dissymmetry factor of |g CP‐ECL | ≈ 1.1. Control experiments and electromagnetic simulations reveal a synergistic mechanism in which chiroplasmonic near‐field induction predominantly breaks the emission symmetry, whereas circular‐polarization‐dependent extinction further amplifies the far‐field circular polarization contrast. Extension to another achiral ECL luminophore suggests that this strategy may be applicable beyond the Ru(bpy) 3 2+ system. By enabling circular polarization without requiring intrinsically chiral luminophores, this approach can be readily integrated with established achiral ECL chemistries and devices, offering opportunities for chiral sensing, electrochemiluminescent photonics, and optical information encoding.