Surface-enhanced Raman scattering (SERS) evaluation protocol for nanometallic surfaces

We present the results of a three-year collaboration between the U.S. Army Edgewood Chemical Biological Center and the U.S. Army Research Laboratory-Aldelphi Laboratory Center on the evaluation of selected nanometallic surfaces developed for the Defense Advanced Research Projects Agency Surface-Enhanced Raman Scattering (SERS) Science and Technology Fundamentals program. The primary role of the two Army labs was to develop the analytical and spectroscopic figures of merit to unambiguously compare the sensitivity and reproducibility of various SERS substrates submitted by the program participants. We present the design and implementation of an evaluation protocol for SERS active surfaces enabling an enhancement value calculation from which different substrates can be directly compared. This method was established to: (1) collect physical and spectral characterization data from the small number of substrates (performer supplied) typically encountered, and (2) account for the complex fabrication technique and varying nature of the substrate platforms encountered within this program.