A sensor with a substrate includes nanowires extending vertically from the substrate, a hafnia coating on the nanowires that provides hafnia coated nanowires, and a noble metal coating on the hafnia coated nanowires. The top of the hafnia and noble metal coated nanowires bent onto one another to create a canopy forest structure. There are numerous randomly arranged holes that let through scattered light. The many points of contact, hot spots, amplify signals. The methods include the steps of providing a Raman spectroscopy substrate, introducing nano crystals to the Raman spectroscopy substrate, growing a forest of nanowires from the nano crystals on the Raman spectroscopy substrate, coating the nanowires with hafnia providing hafnia coated nanowires, and coating the hafnia coated nanowires with a noble metal or other metal.
STATEMENT AS TO RIGHTS TO APPLICATIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
 The United States Government has rights in this application pursuant to Contract No. DE-AC52-07NA27344 between the United States Department of Energy and Lawrence Livermore National Security, LLC for the operation of Lawrence Livermore National Laboratory.
CROSS-REFERENCE TO RELATED APPLICATIONS
 This application claims priority to and benefit under 35 U.S.C. .sctn.119(e) of U.S. Provisional Patent Application No. 61/862,405 filed Aug. 5, 2013 entitled "Reusable Template Based on Metal-Dielectric-CNT Nanowires for Surface-Enhanced Sensitivity," the content of which is hereby incorporated by reference in its entire for all purposes.