The spectra were normalized at a common and maximum peak and averaged. The normalization was performed to exclude the influence of tip-surface specifications using different tips or encountering various surface roughness or laser power fluctuations. The spectra on Au(111) sc /C9t were normalized at approx. 1030 cm -1 assigned to ν s (PO 2 ) -. The spectra on Au(111) sc /PEG-C9t, in the range from 905 w to 1500 were also normalized at ν s (PO 2 ) - to visualize the impact of PEG tethering regardless of molecular orientation change in the spectra. The spectra were normalized at 954 cm -1 in the range from 1400 a to 1900 as a common band for an optimum signal-to-noise ratio. In the higher wavenumber region, the spectra were normalized at 2865 cm -1 assigned to ν(CH) vibration.