Comparing the effects of Fe(III) and Cu(II) on the binding affinity of erlotinib to bovine serum albumin using spectroscopic methods

► Interaction of erlotinib (ET) with BSA in the presence of Cu(II) and Fe(III) was studied. ► Using various spectroscopic methods such as UV, CD, fluorescence and three-dimensional (3D) fluorescence. ► Effects of metal ions on the binding activity of ET to BSA have not been reported. ► Ternary system Cu(II)/Fe(III)-ET-BSA induced the conformational change of BSA.