The characteristics of lysine-mediated self-assembly of gold nanoparticles on the ITO glass

► Lysine played as a cross-linker for the assembly of gold nanoparticles (GNPs). ► α, ɛ-amine mediated cross-linking was dominant at strong acidic conditions (pH2∼3). ► Zwitterions-mediated interaction was favorable at slightly acidic conditions (pH4∼5).