N-Dansyl-carbazoloquinone; a chemical and electrochemical fluorescent switch

A new 'push-pull' molecule having an efficient fluorophore (dansyl) in electronic communication with an active redox quencher (phenyl-carbazoloquinone) through an NH-bridge was designed and synthesized. This all-organic molecule is suggested as a highly reversible 'on/off' molecular switching system. Chemical and electrochemical inter-conversion between the quinone acceptor and the dansyl donor were demonstrated via UV-vis, cyclic voltammetry and fluorescence measurements.