Fig. 7

a Enlarged detail of the reflectance of our PEG-conjugated metasurface in the 1430–1800 cm⁻¹, spectral range measured in a dry environment (blue dashed line), together with the spectral response of the same sample after Neutravidin and Anti-CD63 functionalization (black solid line) and the red-shift compensated reflectance of the PEG conjugated metasurface. b enlarged detail of the reflectance of our PEG-conjugated metasurface in the 1430–1800 cm⁻¹environment (blue dashed line), together with the spectral response of the same device after EV immunocapture and the red-shift compensated reflectance of the PEG conjugated metasurface. c Absorbance in the Amide I/II region of Anti-CD63 and Neutrovidin molecules with (green dashed line) and without (orange dashed line) immunocaptured EVs. d Enlarged detail of the Amide I region for EVs extracted from the Caco2 cells in the Epithelial Phenotype (upper panel) and the mesenchymal Phenotype (lower panel). A peak deconvolutional analysis with gaussian fits is superimposed on each plot