First principal study of interaction of copper doped gold nanoclusters with glycine

•Adsorption energy, UV–Visible spectrum, Reduced Density Gradient (RDG), HOMO-LUMO gap were calculated for all systems.•The Au7Cu nanoclusters and their complexes with glycine have maximum HOMO-LUMO gap therefore they have more stability or less reactivity in comparison to the other nanoclusters in this work.•The maximum adsorption energy is found in the small copper doped gold nanoclusters [Au4Cug(A,B)] and in spherically shaped thirteen atoms nanoclusters [Au12Cug(C)].•Five and fifteen-atom nanoclusters could be observed red shift and eight, thirteen, and eighteen atoms and their complexes have shown a blue shift in the UV–Visible spectra when glycine is adsorbed on Cu doped Au nanoclusters.