Investigation of the reproducibility and repeatability of commercial SERS substrates

Abstract Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for the observation, the detection and the identification of chemical or biological species at low concentrations due to it’s high sensitivity, specific fingerprinting spectra and real-time detection. However, an important task is to define a suitable and reliabale protocol to ensure the reproducibility and repeatability of the SERS measurements in teh framework of SERS sensors. In this paper , a special protocol of measurement have been applied to a commercial SERS Hamamatsu substrate from Hamamatsu Photonics by using diluted solution of 4-mercaptobenzoic acid (MBA) at excitation wavelengths 633nm. This protocol consists in recording 25 SERS maps equally distributed on the whole surface substrate. For each map, 16 spectra have been measure to calculate an average SERS signal of the map. A large set of recorded data for a total of 400 spectra have been collected and analyzed by using the integrated intensities of MBA bands to determine the reproducibility and repeatability of the substrate. This protocol could be applied to other substrates and to precisely evaluate their sensing performances.