Photochemically amplified detection of molecular recognition events: an ultra-sensitive fluorescence turn-off binding assay.

Amplified fluorescence quenching methodology based on massive autocatalytic photo-unmasking of a dual function sensitizer-quencher is developed and adopted for photoassisted ultra-sensitive detection of molecular recognition events. The resulting binding assay, based on a molecular recognition-triggered photo-amplified cascade with concomitant decrease of fluorescence is validated with the biotin-avidin pair, achieving attomolar detection.