Fig. 6
Confocal Raman microscopy characterization of the microspotted fraction D2. a optical image; b typical spectrum of a nanoparticle cluster (top curve) and PS reference (bottom curve), with the light blue spectral zones showing the presence of characteristic PS peaks; c color map of the clusters obtained by the base component analysis, identified as PS. In (a), the PS clusters appear light under white light illumination and are present throughout the deposit. The red box in (a) represents the scanned area by Raman spectroscopy