Development of a Smart Fluorescent Probe Specifically Interacting with C-Myc I-Motif.

I-motifs play key regulatory roles in biological processes, holding great potential as attractive therapeutic targets. In the present study, we developed a novel fluorescent probe with strong and selective binding to the gene promoter i-motif. had an i-motif-binding carbazole moiety conjugated with naphthalimide fluorescent groups. could differentiate the i-motif from other DNA structures through selective activation of its fluorescence, with its apparent visualization in solution. The smart probe showed excellent sensitivity, with a low fluorescent detection limit of 154 nM and effective stabilization to the i-motif. could serve as a rapid and sensitive probe for label-free screening of selective i-motif binding ligands under neutral crowding conditions. To the best of our knowledge, is the first fluorescent probe with high sensitivity for recognizing the i-motif structure and screening for selective binding ligands.