Large-area and cost-effective fabrication of Ag-coated polymeric nanopillar array for surface-enhanced Raman spectroscopy

Abstract

The throughput and cost of surface-enhanced Raman scattering (SERS) substrates are considered the main obstacles for widespread commercialization of this spectroscopy technology. Here, we demonstrate a facile, large-area, and cost-effective method for fabricating SERS substrates based on Ag-coated polyurethane acrylate (PUA) nanopillar arrays. Using a multistep anodization-widening and replication process we could cost-effectively produce the shape-controlled nanopillars and observed a unique beer-bottle morphology arranged in large-area of ca. 150 mm x 95 mm. Due to the softness and flexibility of PUA, the porous anodic aluminum oxide (AAO) template was repeatedly reused without requiring etching of the template to improve the reproducibility of nanopillar arrays. When the beer-bottle-shaped nanopillar array was uniformly coated with Ag nanoparticles and then thermally aged at 50 degrees C, the resulting SERS substrate exhibited a high enhancement factor of 2.8 x 10(6) with a low relative standard deviation of 9.0%. The linear sensitivity of our SERS substrate was also demonstrated, indicating that such a method is promising for developing Ag-coated nanopillar arrays suitable for quantitative chemical sensing. (C) 2018 Elsevier B.V. All rights reserved.