Recent advances in chiral nanoparticle superstructures with long-range order

Long-range ordered chiral nanoparticle superstructures, formed via colloidal self-assembly, exhibit geometrically asymetric structures-such as helices, twisted arrangements, or lattices with low-symmetry space groups-endowed with distinctive chiroptical properties. This review highlights that spherical inorganic nanoparticles typically require chiral templates (e.g., supramolecular polymers, DNA, proteins or liquid crystals) to induce asymmetric spatial organization. In contrast, anisotropic inorganic nanoparticles (e.g., nanorods, tetrahedra, or nanodumbbells) can achieve chiral assembly both with and without templates, the latter driven by interfacial directional forces or geometric curvature matching. These assemblies often exhibit strong chiroptical responses, including high dissymmetry factors (g-factors) and circularly polarized luminescence (CPL), with tunable performance via precise control of interparticle spacing, helical pitch, and other structural parameters. Chiral nanoparticle superstructures present versatile platforms for applications in circularly polarized optoelectronics, metamaterials, biosensing, and drug screening. Future directions include uncovering the mechanisms of chirality transfer and exploring strong coupling effects, paving the way for advances in quantum photonics and precision medicine.