The ability to rationally manipulate plasmonic nanoparticles into well‐defined hierarchically patterned arrays is crucial for exploiting the property of novel optical metamaterials and is of significance for designing plasmonic devices. Before the benefits offered by hybridized plasmon modes may be fully utilized in practice, programmable plasmonic nanostructures with preset morphology and composition should be developed in advance. However, it remains a grand challenge to fabricate large‐area patterned array with highly ordered nanostructure in a low‐expertise and straightforward route. Here, high‐throughput fabrication of multiscale patterned plasmonic arrays of macroscopic surfaces and nanoscale ordering is reported. The bottom‐up ligand‐guided crystallization of nanoparticles takes place upon drying‐mediated self‐assembly at air/solution/substrate interfaces, while the macroscopic topography is regulated by rational control over local nucleation in microwrinkles. Using bimetallic nanobricks as meta‐atoms, it is demonstrated that the configuration of patterned arrays can be finely engineered as required by simply customizing the wrinkled template. It is also proved that the fabricated plasmonic arrays exhibit nearly uniform hot‐spot distribution across the entire surface, which makes them as practical substrates for the surface‐enhanced Raman scattering (SERS) applications. This facile yet efficient methodology suggests a versatile step toward the fabricating of hierarchically patterned architectures for practical device construction.

Plasmonic superlattice membrane exhibits remarkable functional properties that are emerging from engineered assemblies of well-defined "meta-atoms," which is featured as a conceptual new category of two-dimensional optical metamaterials. The ability to build plasmonic membranes over macroscopic surfaces but with nanoscale ordering is crucial for systematically controlling the light-matter interactions and represents considerable advances for the bottom-up fabrication of soft optoelectronic devices and circuits. Through rational design, novel nanocrystals, and by engineering the packing orders, the hybridized plasmon signature can be customized, promoting controllable near-field confinement for surface-enhanced Raman scattering (SERS) based detection. However, building such 2D architectures has proven to be remarkably challenging due to the complicated interparticle forces and multiscale interactions during self-assembly. Here, we report on the fabrication of ultralong-nanobrick-based giant plasmonic superlattice membranes as high-performance SERS substrates for ultrasensitive and label-free protein detection. Using aspect-ratio controllable short-to-ultralong nanobricks as building blocks, we construct three distinctive plasmonic membranes by polymer-ligand-based strategy in drying-mediated self-assembly at the air/water interfaces. The plasmonic membranes exhibit monolayered morphology with nanoscale assembled ordering but macroscopic lateral dimensions, inducing enhanced near-field confinement and uniform hot-spot distribution. By choosing 4-aminothiophenol and bovine serum albumin (BSA) as a model analyte, we establish an ultrasensitive assay for label-free SERS detection. The detection limit of BSA can reach 15 nM, and the enhancement factor reached 4.3 × 10 5 , enabling a promising avenue for its clinical application in ultrasensitive biodiagnostics.

The self-assembly of plasmonic building blocks into superlattices has emerged as a promising route to fabricate metamaterials with customizable nanoscale architecture and collective properties. However, self-assembly of such plasmonic superlattice has proven challenging, owing to the low packing fraction, complex interparticle forces, and local heterogeneity. Besides, the conventional assembly of small nanoparticles usually exhibits localized defects and uncontrollable electromagnetic field distribution, limiting its functionality for real-world application. Here, we report on the self-assembly of multifacet gold nanopolyhedron (AuNPH) into high-quality giant plasmonic superlattice sheets. This bottom-up method involves soft ligandbalanced crystallization of AuNPHs in conjunction with drying-mediated self-assembly. Such AuNPHs superlattice sheets exhibit macroscopic surface area while maintaining a highly ordered nanoscopic structure. We also demonstrate by both experiment and theoretical simulation that the surface-plasmon-induced hotspots are uniformly distributed across the sheet surface, facilitating its application as flexible surface-enhanced Raman scattering (SERS) sensors for detection of 4-aminothiophenol. The Raman enhancement factor (EF) of this flexible SERS sensor can reach 1.7 × 10 6 with a detection limit reaching the nanomolar scale. Moreover, the Raman signals exhibited high homogeneity across the superlattice sheets with a low relative standard deviation of 4.3%. Such flexible AuNPHs superlattice sheets can be applied as nonconventional SERS platforms with well-defined customizability, suggesting a robust and efficient avenue for real-world applications in high-sensitive inspection of drugs, explosives, and environmental pollutants.