Top: far-field spectrum (global spectrum acquired with a Nicolet Continuum II IR microscope on the SOLEIL SMIS beam line) of UCAMM DC16-07-18b. The inset displays the spectrum in the range covered by the laser for the AFMIR measurements. The band at 1710 cm⁻¹ (green) is attributed to C=O, while the band at 1600 cm⁻¹ (red) reflects the presence of C=C/C=N bonds. Bottom: false colour maps showing the measured intensity maps of the bands at 1710 cm⁻¹ (green) and 1600 cm⁻¹ (red), and a composite image (red-green). Bottom right: topographical map recorded during the AFM measurements (greyscale).