Targeting imaging and enhanced radiotherapy are very important issues for decrease in diagnosis and therapy. Functionalized gold nanostructures show low toxicity and excellent optical properties, and thus, they can be used as the contrast agent in cancer cell imaging. Furthermore, gold nanostructures can enhance radiotherapy due to strong photoelectric absorption and second electron caused by gamma or X-ray irradiation. This critical review provides a recent progress in fabrication, optical properties (especially, fluorescence of nanoclusters), surface modification, targeting imaging, and enhanced radiotherapy of gold nanostructures. It will interest the radiation medicine, chemistry, spectroscopy, biochemistry, biophysics, and nanoscience communities.
Keywords: Gold nanoparticles, nanoclusters, cancer cell imaging, radiotherapy, Nanostructure, Fabrication,, Surface Modification, Targeting Imaging,, Enhanced Radiotherapy, photoelectric absorption, surface plasmon resonance, novel photolumi-nescence, Gold colloids, microwave irradiation, chemical reduction, auric acid, nanorods, nanocages, Turkevich method, sodium borohydride, Seed-mediated growth method, hydroxylamine hydrochlo-ride, hexadecyltrimethylammonium bromide, monodispersity nanorods, nanocrystals, polyvinylpyrrolidone (PVP), polyacrylamide gel electrophoresis (PAGE), near infrared (NIR) region, PEG- Au Nanoparticle Bioconjugation, Antibody-Au Nanoparticle Bioconjugation, Thiol protection, etching method, Toxicity of Nanostructures, brachytherapy, radiosensitization