Rapid Synthesis of Size-controlled Gold Nanoparticles by Complex Intramolecular Photoreduction

A rapid synthesis of size-controlled gold nanoparticles was proposed. The method is based on the sensitive intramolecular photoreduction reaction of Fe (III)-EDTA complex in chloroacetic acid-sodium acetate buffer solution, where Fe(II)-EDTA complex generated by photo-promotion acts as a reductant of AuCl−4 ions. Gold nanoparticles formed were stabilized by EDTA ligand or other protective agents added. As a result, well-dispersed gold nanoparticles with an average diameter range of 6.7 to 50.9 nm were obtained. According to the characterizations by the UV spectrum and TEM, the intramolecular charge transfer of the excited states of complex Fe(III)-EDTA and the mechanism of forming gold nanoparticles were discussed in detail.