Naphthalene-based environmentally sensitive fluorescent 8-substituted 2′-deoxyadenosines: Application to DNA detection

We synthesized various C8-naphthylethynylated 2′-deoxyadenosine derivatives and investigated their photophysical properties. Among them, cyano- and N,N-dimethylamino-substituted 8-naphthylethynylated 2′-deoxyadenosine derivatives (^cnA and ^dnA) showed strong fluorescence with high quantum yields and a remarkable solvatofuorochromicity. In particular, fluorescence of N,N-dimethylamino-substituted ^2,6dnA was not quenched by neighboring guanines (Gs) when incorporated in DNA duplexes, in contrast to ^cnA. We developed a new fluorescent probe containing ^2,6dnA that can be used for the detection of target DNA via a bulge formation regardless of the neighboring sequences.