Development of sorptive sers platforms for identification of chemical threats in gas phase

Resumen del póster presentado a la XXXVIII Reunión Bienal de la Real Sociedad Española de Química, celebrada en el Palacio de Congresos de Granada, del 27 de junio al 30 de junio de 2022.Surface Enhanced Raman Spectroscopy (SERS) is one of the leading techniques for specifically acquiring a label-free, ultrasensitive, vibrational fingerprint of a variety of molecular compounds. However, trace level detection (ppbV) of gaseous compounds is hampered by the fact that only a few molecules will be in the region of substrate signal amplification (“hot-spots”). Thus, our objective is to advance in the development of SERS substrates, based on distinct plasmonic/metallic nanoparticles, for a more robust, ultrasensitive, and reliable gas detection. Here we present a SERS substrate series fabricated from core-shell nanostructures comprising Au@Ag rod nanoparticles (of tunable size and aspect ratio) as the core and mesoporous silica-based material (MCM-48) as the shell. The high surface area and specific sorption properties of MCM-48 is of interest to preconcentrate gaseous molecules at the amplification regions of the metallic cores, where the electromagnetic field is amplified due to the localized plasmon resonance effect. The resulting nanostructure is denoted as Au@Ag@MCM-48. The SERS substrates series is obtained by spin coating the colloidal suspensions on transparent glassware/holders. Its performance considers the analytical enhancement factor (AEF) as a comparative parameter and was calculated for the standard molecule 4-nitrothiophenol (4-NBT). The current substrate fabrication conditions are being improved for a more reliable gas detection of, at present, the Sarine surrogate DMMP. At the moment, our efforts in the European project SERSing (EU H2020 grant agreement nº 883390) are dedicated in evaluating the SERS performance of these substrates in the gas-phase detection of nerve substitutes and vesicants.Peer reviewe