Specific (host–guest) and unspecific (substrate–guest) interactions between self-assembled monolayers of cucurbituril (CB) on gold (Au) substrates and neutral adamantyl (Ad) guests were resolved by studying these interactions at the single molecule level using dynamic force spectroscopy. The dissociation rate constants of the Ad–Au and the Ad–CB interactions were 0.3 s–1 and 0.03 s–1, respectively, indicating that the specific binding is more stable. The probability of observing a specific interaction (40 ± 9%) is similar to the reported surface coverages of CB monolayers on Au substrates. The higher strength and stability of the Ad–CB interactions explains why, although presenting an imperfect coverage, CB[n] monolayers can be used successfully as a platform for surface immobilization.
|Number of pages||6|
|Publication status||Published - 2011|