A fluorescent perylene dye with two aromatic units was designed for binding to cucurbit[8]uril. The binding affinity of the complexes increased about 3 orders of magnitude compared to the dye without a secondary aromatic unit. The high affinity allows the complexes to act as fluorescent probes for detection of strong binding guests with nanomolar sensitivity.

We have developed host–guest fluorescent complexes based on cucurbit[8]uril and a perylenemonoimide for selective and sensitive detection of N-terminal phenylalanine peptides.

A napthalimide based fluorescenct sensor displaying a significant increase in emission upon binding CB[7] with excellent pH stability was developed and utilized in a surface-bound displacement assay for the rapid detection of CB[7] encapsulation of therapeutically relevant drug classes. Previously unknown binders with moderate to strong affinities were discovered.