Ordered Anodic Aluminum Oxide-Based Nanostructures for Surface-Enhanced Raman Scattering: A Review

As a promising spectroscopic technique, surface enhanced raman spectroscopy (SERS) has been intensively used in bio/chemical sensing, attributing to its unique advantages of ultrasensitive and accurate detection of trace amounts of analytes, high specific fingerprint-like features, fast response, and noninvasive sensing. The robustness and consistency of SERS signals in practical analytical applications highly rely on the composition, structural morphology, and uniformity of SERS substrates. These factors play a pivotal role in determining the intensity and reproducibility of the detected signals. SERS substrates based on ordered nanostructures that are fabricated from anodic aluminum oxide (AAO)-template-assisted approaches are of significant interest due to their cost effectiveness, scalability, precise structural control, and exceptionally ordered features. In this review, recent progress in SERS substrates with high sensitivity and reproducibility prepared from AAO templates is highlighted. We emphasize the optimization strategies toward achieving efficient SERS-active substrates by fine-tuning the size, composition, and morphology of AAO-derived ordered nanostructures. Furthermore, we delve into the discussion of flexible and smart SERS substrates, while also exploring key aspects pertinent to further amplifying SERS signals. Overall, this review aims to offer insights into the future integration of the AAO templates technique with SERS, providing crucial perspectives for forthcoming research in this field.