Light-up fluorescent probes utilizing binding behavior of perylenediimide derivatives to a hydrophobic pocket within DNA

Here we study the binding behavior of perylenediimide (PDI) derivatives to a hydrophobic pocket created inside DNA and their photochemical properties capable of designing a light-up fluorescent sensor for short single-stranded DNA or RNA. The perylenediimide derivative with alkoxy groups (PO) suppressing electron transfer quenching was examined. The PO bound randomly to DNA showed negligible fluorescence due to the aggregation-induced quenching, whereas the PO bound to the pocket as a monomeric form showed more than 100-fold fluorescence enhancement. Switching the binding states of the PO corresponded to a change in the fluorescence response for the hybridization event, which allowed us to design a fluorescent sensor of nucleic acids with a nanomolar detection limit.