SERS active gold nanostructures for selective and ultrabright biolabelling: synthesis and quantitative study

Surface enhanced Raman scattering (SERS) probes based on gold nanoparticles (AuNPs) \u2013 organic dyes nanocomposites disclosed new opportunities for multiplexed ultrasensitive biolabelling in vitro or in vivo. SERS labels also have excellent biocompatibility and can be excited with near infrared laser sources, that match the transparency window of biological tissues. Here we report about the preparation of AuNPs obtained by laser ablation synthesis in solution (LASiS)[1,2] and their functionalization with a series of Raman reporter with different spectral fingerprints. The effective differential Raman scattering cross section of these labels were evaluated using liquid Raman standards and the analysis of the surface plasmon band of AuNPs with the Mie \u2013 Gans models.[3] We estimated that few (