Thrombin Assessment on Nanostructured Label-Free Aptamer-Based Sensors: A Mapping Investigation via Surface-Enhanced Raman Spectroscopy

Figure 4

Regional mapping of the SERS substrate for 87.3 nM thrombin concentration. (a), (b), and (c) show the individual Raman maps for the characteristic bands, while (d) reports the combined map and (e) reports the resulting one after applying the threshold of 60%.