Protonation of acridine orange in dye-surfactant ion pair micelles

► Acridine orange forms protonated dye-surfactant ion pair with anionic surfactants. ► Spectrophotometric and surface tension behavior evidence the formation. ► Two CMC's of the surfactants in presence of AO revealed from surface tension. ► Fluorescence behavior provides insight to the microenvironment of AO.