Morphological Control of Gold Nanoparticles by Green Synthesis Using l-Tryptophan and Other Additives

This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent l -Tryptophan ( l -Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV–Vis spectrophotometer and X-ray diffraction (XRD) for size and morphological information. The effects of the specific additives of PVP ((C 6 H 9 NO) n ), CTAB (C 16 H 33 (CH 3 ) 3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.