A Plasmonic Coupling Substrate Based on Sandwich Structure of Ultrathin Silica-Coated Silver Nanocubes and Flower-Like Alumina-Coated Etched Aluminum for Sensitive Detection of Biomarkers in Urine

作者：Minh Kha Nguyen; Su Wei Nien; Hwang Bing Joe^*

来源：Advanced Healthcare Materials, 2017, 6(10): 1601290.

DOI：10.1002/adhm.201601290

Interactions between substrate and plasmonic nanostructures can give rise to unique optical properties and influence performance in plasmonic biosensing applications. In this study, a substrate with low refractive index and roughness based on flower-like alumina-coated etched aluminum foil (f-Al2O3/e-Al) has been fabricated. Silver@silica (Ag@SiO2) nanocubes (NCs) assemble in an edge-edge configuration when deposited on this substrate. The rough surface texture of f-Al2O3/e-Al provides a pathway for coupling of incident light to surface plasmons. The Ag@SiO2/f-Al2O3/e-Al substrate exhibits a coupling efficiency of laser light sources into surface plasmon hotspots for both surface-enhanced Raman scattering (SERS) and metal-enhanced photoluminescence (MEPL). Moreover, the shelf life of this substrate is significantly improved due to a reduction in oxygen diffusion rate mediated by the ultrathin silica spacer and the flower-like Al2O3 dielectric layer. Creatinine and flavin adenine dinucleotide are biomolecules present in human blood and urine. With advanced label-free SERS and MEPL techniques, it is possible to detect these biomarkers in urine, allowing cheap, noninvasive, yet sensitive analysis. The approach explored in this work can be developed into a powerful encoding tool for high-throughput bioanalysis.

• 出版日期2017-5-24