Easy-to-make-and-use gold nanotrench arrays for surface-enhanced Raman scattering

Abstract

To achieve a surface-enhanced Raman spectroscopy (SERS) sensor that is easy to make and use, we propose periodic gold nanotrench arrays, which can be fabricated without surface contamination and intricate sensor alignment. Deep and narrow plasmonic nanotrenches for amplifying local electromagnetic fields were reliably generated on a wafer-scale substrate by nanoimprint lithography and two successive oblique-angle depositions. Electromagnetic simulations and Raman measurements show that the proposed plasmonic nanostructures function as SERS sensors, enabling nanomolar sensitivity. Furthermore, we successfully confirmed the microRNA detection capability of the proposed nanostructures to demonstrate their promising potential and feasibility for use in biomedical diagnostic sensors.