The dependencies shown in Fig. prove that the ratio of the marker bands and the centroid of the marker bands region can be used to reliably estimate the composition of the surface layer comprising Cys-cabn and Cys-CABN molecules adsorbed onto AgNPs in the selected concentration regime. This approach was further employed to investigate the changes in the composition of the monolayer in the temperature-dependent SERS measurements of the exchange of the two isotopologues at the surface of AgNPs.