Complexes between C.I. Acid Orange 6 and human serum albumin, a multi-spectroscopic approach to investigate the binding behavior

► Utilized multi-spectroscopy technique and molecular modeling method. ► Investigated the interaction between AO6 and HSA qualitatively and quantitatively. ► The intrinsic fluorescence of HSA was quenched through dynamic quenching mechanism. ► The addition of AO6 can induce the conformational changes of HSA. ► Both hydrophobic forces and hydrogen bonding play a major role in the interaction.