One-pot radiolytic synthesis of gold nanorods and their optical properties

A novel one-pot synthesis method to prepare gold nanorods of different aspect ratios using radiolysis is presented. The gold nanorods are synthesized by radiolytic reduction of AuIII complexes in a micellar solution formed by a mixture of cationic surfactants (cetyltrimethylammonium bromide and tetraoctylammonium bromide) and in the presence of acetone and silver ions. The mechanisms of reduction of gold complexes and formation of the nanorods are discussed. The nanorods can be trapped in a poly(vinyl alcohol) gel formed under irradiation. The UV-visible absorption spectra of nanorod solutions are compared with calculations performed by using the discrete dipole approximation method, underlying the effect of the rod aspect ratio distribution.