Design and Synthesis of a Dimethylindole Red Trimer: A New Light‐Up Red‐Emitting Fluorescent Probe for G‐Quadruplexes

Abstract

AbstractWe present a zwitterionic fluorescent probe based on dimethylindole red (Dir) derivative (named Dir‐Trimer), which was synthesized by organic amine covalently linking three red‐emitting Dir units. The unique structure of Dir‐Trimer with three zwitterionic units largely decreased its intrinsic fluorescence. Fluorescence experiments exhibit that Dir‐Trimer selectively interacts with G‐quadruplexes with large fluorescence enhancement and sensitivity. Further studies indicate that Dir‐Trimer could visualize G‐quadruplexes on cell level.