Efficient Fluorescence Enhancement and Cooperative Binding of an Organic Dye in a Supra‐biomolecular Host–Protein Assembly

A factor of 300 enhancement in fluorescence and increased binding is observed when the triphenylmethane dye Brilliant Green binds to bovine serum albumin (BSA) in the presence of the macrocyclic host cucurbit7uril (CB7) as a supramolecular “enhancer” (see picture). Thus, a cumulative (multiplicative) fluorescence enhancement occurs compared to the effects observed in the presence of CB7 alone (factor of 6) or BSA alone (factor of 45).