AFM-IR characterization of the Ryugu IOM A0106-IOM residue_3, zoom-in on the organic nanoparticles identified in situ in Fig. 3. (a) RGB image of the region including the organic nanoparticles (C=O at 1720 cm⁻¹ in red, C=C at 1600 cm⁻¹ in green, CH_X 1460 cm⁻¹ minus 1520 cm⁻¹) in blue. The white line shows the location of individual AFM-IR spectra taken across one organic nanoparticle. The colored dots (S₁ to S₃) correspond to the average spectra taken on each side (S₁ and S₃ in blue) and on the organic nanoparticle (S₂ in red). (b) Intensity ratios of frequencies corresponding to CH_X/C=C (1460/1600) and C=O/C=C (1700/1600) along the white line shown in (a). The location of the S₁ to S₃ spectra is recalled on the left axis. (c) Average AFM-IR spectra on each side (blue, S₁ and S₃) and on the organic nanoparticle (red, S₂).