Pyrene acetylide nucleotides in GNA: probing duplex formation and sensing of copper(II) ions

The synthesis and evaluation of GNA duplexes containing fluorescent pyrene and pyrene acetylide nucleotides is reported. Interestingly, only the pyrene acetylides, but not the related plain pyrene nucleotides, form strong excimers upon stacking in glycol nucleic acid (GNA) duplexes. The ability of the large pyrene acetylide nucleotide to be accommodated in GNA duplexes opposite an abasic site was investigated by molecular modeling. The interstrand pyrene acetylide excimer formation was used to monitor GNA duplex formation and was applied to the design of a copper(II)-selective "turn-on" fluorescence sensor.