Self-Assembly of Glutamic Acid and Serine on Au(111).

Amino acids provide novel and superior performance for two-dimensional materials and bio-based devices. The interaction and adsorption of amino acid molecules on substrates have thus attracted extensive research for exploring the driving forces involved in the formation of nanostructures. Nevertheless, the interactions within amino acid molecules on inert surfaces have not been fully understood. Herein, from the interplay of high-resolution scanning tunneling microscopy imaging and density functional theory calculations, we show the self-assembled structures of Glu and Ser molecules on Au(111), which are dominated by intermolecular hydrogen bonds, and further investigate their most stable structural models at the atomic scale. This study would be of fundamental importance in understanding the formation processes of biologically relevant nanostructures and provide possibilities for chemical modification.