Related publication: De Marchi, S; García-Lojo, D; Bodelón, G; Pérez-Juste, J; Pastoriza-Santos, I. Plasmonic Au@Ag@mSiO2 Nanorattles for In Situ Imaging of Bacterial Metabolism by Surface-Enhanced Raman Scattering Spectroscopy. ACS Applied Materials & Interfaces 2021. DOI: 10.1021/acsami.1c21812. Abstract: It is well known that microbial populations and their interactions are largely influenced by their secreted metabolites. Noninvasive and spatiotemporal monitoring and imaging of such extracellular metabolic byproducts can be correlated with biological phenotypes of interest and provide new insights into the structure and development of microbial communities. Herein, we report a surface-enhanced Raman scattering (SERS) hybrid substrate consisting of plasmonic Au@Ag@mSiO2 nanorattles for optophysiological monitoring of extracellular metabolism in microbial populations. A key element of the SERS substrate is the mesoporous silica shell encapsulating single plasmonic nanoparticles, which furnishes colloidal stability and molecular sieving capabilities to the engineered nanostructures, thereby realizing robust, sensitive, and reliable measurements. The reported SERS-based approach may be used as a powerful tool for deciphering the role of extracellular metabolites and physicochemical factors in microbial community dynamics and interactions.

This work was supported by the Xunta de Galicia/FEDER (grant GRC ED431C 2020/09). G.B., J.P.-J., and I.P.-S. acknowledge financial support from the MCIN/AEI /10.13039/501100011033 (grant nos. PID2019-109669RB-I00, PID2019-108954RB-I00, and BES-2017-081670) and Ramon Areces Foundation (Grant SERSforSAFETY). G.B. acknowledges financial support from the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2019-2022) and the European Union (European Regional Development Fund-ERDF).