Facile Fabrication of Metallic Nanoembossing Surfaces Using Anodic Aluminum Oxide-Derived Nanobowl Templates

Periodic nanostructures interact strongly with light, producing unique optical responses such as structural coloration, surface plasmon resonance (SPR), and photonic-crystal effects that are promising for optical devices and sensing applications. However, conventional nanofabrication techniques are costly, complex, and challenging to scale to large areas. Here, we introduce a facile, highly reproducible replication strategy for fabricating large-area Au and Ag nanoembossing surfaces from anodic aluminum oxide (AAO) based nanobowl templates. Microscopic analyses confirm faithful, high-fidelity transfer of the nanobowl morphology into the metallic films, while UV–ozone (UVO) pre-treatment tailors surface wettability and enables defect-free stripping of the noble-metal layers. Notably, the optical response critically depends on structural periodicity: substrates with a larger periodicity (~ 260 nm) exhibit pronounced spectral modulations and vivid structural coloration, whereas those with a smaller periodicity (~ 80 nm) show no visible color change, underscoring periodicity and geometry as key design parameters governing plasmonic responses. The proposed replication strategy is simple, reproducible, and extendable to various metals and dimensions, offering a versatile platform for next-generation plasmonic devices, including structural color filters, anti-counterfeiting tags, and optical sensors.