Recent advances in nanoporous AAO based substrates for surface-enhanced raman scattering

Abstract

Nanoporous anodic aluminium oxide (AAO) has become one of the most attractive engineered template for sensing, drug delivery, catalysis, photonics, electronics, energy generation, and storage applications. The formation of AAO is based on the low-cost self-ordering anodization of pure aluminium, which provides perpendicularly aligned, well-organized nanoporous structures with hexagonal symmetry. Due to its distinctive physical and chemical characteristics, it has been widely examined for the development of advanced, cheap, reproducible, and portable sensing devices. On the other hand, from the last few decades, surface-enhanced Raman scattering (SERS) spectroscopy has drawn a wide range of attention because of its label-free detection capability and extreme sensitivity towards the detection of a lower limit of analytes. The key barrier to the extensive use of SERS for regular recognition is the lack of reproducibility of the substrate (periodicity, surface roughness, thickness) as well as the signal (wavelength position and intensity) which are significant for SERS applications. This paper provides a review of AAO templates for the fabrication of reproducible SERS active substrate for sensing various kind of molecules.