Fabrication of Au-Decorated Al Nanoconcavities Platform for Augmented SERS

Abstract

A robust and competitive technology to synthesize arranged high-density gold nanoparticles on highly uniform Al nanoconcavities substrates is presented. The nanoparticles are formed through sputtering and thermal annealing treatment on Al templates, which are synthesized through particular removal of nanoporous anodic alumina structure with controlled anodization conditions and with phosphoric acid as electrolyte. This scalable fabrication mechanism regulates the particle size, arrangement, shape and interparticle separation across large surface areas, which empowers the optimization of their surface enhanced Raman scattering (SERS) activities. 4-mercaptopyridine is selected as a probe molecule. Analysis reveals that Au-decorated Al nanoconcavities substrates are highly competitive for the enhancement of Raman signals and could be employed as self-sustaining nanosensors. By using these templates, a concentration as low as 10−7 M of 4-mercaptopyridine is easily detected. Finally, the calculated EF factor of 1.1 × 107 confirms the suitability for effective and sensitive SERS detection of the developed substrates.