Preparation and characterization of some gold nanometric compounds with simple organic materials as precursor: Spectroscopic, biological and anti-cancer assessments

This study reports the synthesis of the gold nano-particles assembly mediated by some amino acids, such as ornithine (Orn), isoleucine (i-Leu), serine (Ser) and histidine (His). The structural characterization of [Au2(AA)2(Cl)2]2+Cl2 (where AA = Orn, i-Leu, Ser and His) compounds were done by using elemental analysis, molar conductance, FT-IR, Raman, UV–vis, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) spectroscopy. It has been found from the elemental analysis, spectroscopic and the thermal studies that the amino acids ligand behaves as bidentate ligand forming chelates with 1:1 (metal:ligand) stoichiometry. The molar conductance measurements of the complexes in DMSO indicate that the complexes are electrolyte. The thermal decomposition mechanisms were discussed for compounds Orn, i-Leu, Ser and His and occurred in two consecutive steps. The TG curves of the gold(III) compounds suggest the loss of the ligands (Orn, i-Leu, Ser and His) within two steps, with probable formation of a gold free metal. The biological and anti-cancer activities (Breast carcinoma cells (MCF-7-cell line) of the nano-sized complexes have also been studied.