Broadband SERS detection with disordered plasmonic hybrid aggregates

Nanoscale. 2020 Jan 7;12(1):93-102. doi: 10.1039/c9nr08118f. Epub 2019 Nov 1.

Abstract

Plasmonic nanostructures possessing broadband intense field enhancement over a large area are highly desirable for nanophotonic and plasmonic device applications. In this study, 3D Ag hybrid nanoaggregates (3D-Ag-HNAs) are achieved via a highly efficient oblique angle gas-phase cluster beam deposition method. Not only can such structures produce a high density of plasmonic hot-spots to improve Raman sensitivity, but more importantly they generate kissing point-geometric singularities with a broadband optical response. We succeed in obtaining an experimental SERS enhancement factor beyond 4 × 107 in the visible range, providing an optimal sensing platform for different analytes. Combined with good uniformity, reproducibility and ease of fabrication, our 3D-Ag-HNA offers a candidate for new generations of SERS systems.