Through Diamond Robust Surface Enhanced Raman Spectroscopy

ABSTRACT Surface‐Enhanced Raman Spectroscopy (SERS) is a form of Raman spectroscopy which utilizes nanoparticle plasmonic interactions to enable trace‐level molecular measurement. However, conventional SERS measurements are restricted to the laboratory environment due to the fragile nature of the plasmonic nanostructures required. Therefore, to enable the use of SERS in extreme environments for in situ analysis, a robust and chemically stable plasmonic substrate is required. Moreover, the deployment of SERS systems in extreme environments would be greatly enhanced if the optical illumination technology could be placed behind a SERS active surface. Laboratory‐based growth of thin diamond films offers a unique opportunity for SERS substrates; the encapsulation of plasmonic nanostructures within a transparent, chemically stable, and physically robust shell. In this work, the diamond acts as both a window and protective layer, enabling illumination of the plasmonic nanostructures through the diamond itself, with light stimulating NPs encapsulated on the opposite face. This innovative ‘rear‐illumination’ approach enables spectrometer protection via through‐diamond measurements. nm Au nanostructures have been encapsulated in varied diamond film thicknesses, providing an optimized SERS enhancement of 6.2 10 3 . This enhancement is comparable to commercially available SERS substrates, while the novel diamond platform offers conceivably near‐infinite reusability in virtually any environment.