A CuAu₃₈ bimetallic nanocluster was synthesized by adding a single copper atom to the Au₃₈(2-PET)₂₄ nanocluster. The absence of Cu_xAu₃₈(2-PET)₂₄ doped species was demonstrated by MALDI-TOF mass spectrometry. A separation of bimetallic clusters was attained for the first time where isomers of the E2 enantiomer of the Au₃₈Cu₁(2-PET)₂₄ adduct were successfully isolated from their parent cluster using chiral HPLC. The CD of the isolated isomers revealed a change in their electronic structure upon copper addition. The luminescence of the Au₃₈Cu₁ adduct is significantly enhanced in comparison with the parent Au₃₈ nanocluster. The stability of the newly formed adduct is strongly dependent on the coexistence of the Au₃₈ nanoclusters.