Mercaptohexanol assembled on gold: FM-AFM imaging in water

Mercaptohexanol is adsorbed on gold (1 1 1) and probed in an aqueous KCl solution by frequency-modulation atomic force microscopy (FM-AFM). Two different features, dot-like and rod-like protrusions, appear in the surface topography. Laterally periodic modulation of the solution density is recognized in the tip-surface force distribution cross-sectional to the surface. A possible assembly of mercaptohexanol, in which two mercaptohexanol molecules are laid down in a rectangular ( 3 × 2 3 ) unit cell, is proposed to explain the experimental results.