Single molecular anatomy of solvophobic effects in host-guest interactions based on surface tension using atomic force microscopy.

The effectiveness of the mechanism of surface tension to analyze the host-guest interaction was demonstrated by measuring the unbinding force of the beta-Cyclodextrin (CyD)--adamantane molecules in a liquid environment at the single-molecule level. The contribution of the solvophobic effect was quantitatively distinguished from the intrinsic van der Waals force, and the effective length that produces the detected force through employing the notion of surface tension was determined to be , which is consistent with the perimeter of the adamantane molecule, . Specific strong interaction of water molecules was also confirmed on the nanoscale.