Blue-red emitting 2,12-disubstituted [5]helicenes for high fluorescence efficiency and sensing application

•We report photochemical synthesis of two new fluorene and carbazole-based 2,12-disubstituted [5]helicenes for Fe3+ ion sensor.•For the first time, we have extended our study to security purpose, here both dyes showed excellent application under excitation at 365 nm.•Both dyes FLU-HEL and CBZ-HEL can be used as a fluorescent ink under excitation at 365 nm, and can also replace traditional inks for security purposes.