The enhancing properties of silver nanoparticles in surface-enhanced Raman scattering (SERS) and metalenhanced uorescence (MEF) are studied in this work. The obtained results conrm that the partial aggregation of nanoparticles leads to a great increase of Raman scattering cross-section but there are signicant dierences in SERS-activity of colloidal silver treated with various aggregating compounds. The dierences are interpreted through the analysis of both experimental and computational results. The same silver colloid covered with silica shell preventing the uorescence quenching makes possible a several-fold increase in uorescence emission. The eect strongly depends on thickness of the outer layer of nanoparticles. Geometrical parameters of nanoparticles (radius or radius and thickness of the adsorption layer in core-shell systems) are determined on the basis of the dynamic light scattering (DLS) data and extinction spectra analysis
