Tuning the shape and size of hybrid gold nanoparticles by porphyrins using seed-mediated synthesis

We report the synthesis of hybrid gold nanostructures by means of seed/growth approach, using porphyrin molecules (protoporphyrin IX) in addition to cetyltetraammonium bromide (CTAB) as surfactants and/or shape-modulating agents. The combination of CTAB and porphyrin yields stable complexes that act as co-directing agents and favor the anisotropic growth of gold nanostructures. Our results revealed the ability of porphyrins to tune the shape and size of gold nanostructures, leading to the formation of a variety of hybrid nano-objects, including bones, thorns, polyhedral and stars.