Cucurbit[n]uril assemblies for biomolecular applications

Cucurbit[n]urils (CB[n]s) provide a class of macrocycles that are able to form stable host–guest complexes with various guests. A wide range of potential guests has stimulated an increasing number of fundamental molecular recognition studies that led to various biomolecular applications. The systems are intrinsically dynamic and can rearrange, while some of the interactions are reversible upon stimuli. We have discussed the origins of the molecular recognition properties of the CB[n] family and methods to gain control over the binding affinity to CB[n]. We have described the amino acid based recognition of CB[n] and subsequently review the literature on how these properties can be successfully employed to dynamically probe the properties and function of peptides, proteins and cells, which is important for bioanalytical and biomedical applications.