A turn-on dual emissive nucleobase sensitive to mismatches and duplex conformational changesElectronic supplementary information (ESI) available: Experimental procedures, analytical data, and spectra. See DOI: 10.1039/c6ra19061h

Herein, a 2-furyl-3-hydroxychromone-based deoxyuridine analogue was synthesized and incorporated into DNA. Its ESIPT mechanism, investigated by steady-state and time-resolved spectroscopy, was found to be highly sensitive to hydration through its ratiometric response. As a result, this analogue demonstrated a unique on-off dual emissive behavior which allows monitoring DNA hybridization as well as discriminating matched from mismatched duplexes, and B from A conformations. Herein, we demonstrate the on-off dual emissive behaviour of a fluorescent nucleoside sensitive towards DNA hybridization and conformational changes as well as detection of single nucleotide polymorphisms.