2-Arylazo-imidazolium was investigated as a new hydrophilic head group for ionic liquid surfactants. With the azo moiety at the 2-C site of imidazolium, it was designed to expand the extensibility of the functionalization and controllability of assembly. Structural designability was displayed by the colloidal chemical properties like surface tension, conductivity and steady fluorescence quenching of the designed surfactants. Their corresponding responsiveness towards photo stimuli was compared. Further properties like the reversible electrochemical redox responsiveness and the instinctive fluorescence of the designed surfactants were discovered. A potential application was demonstrated by the photo-controllable fabrication of Au nanostars.