An enhanced synthesis of gold nanorods by the addition of Pluronic (F-127) via a seed mediated growth process

The synthesis of stable gold nanorods with higher aspect ratios ( similar to 15-20) and more enhanced uniformity by a modified seed mediated growth approach is reported. A binary surfactant system consisting of CTAB and Pluronic F-127 was used to overcome limitations of the previous approach prepared in the presence of AgNO3: the continuous blue-shifting of the plasmon absorption peaks and the reshaping of the gold nanorods upon storage. The addition of Pluronic F-127 resulted in higher yield and better uniformity of the synthesized nanorods. It also led to the enhanced production of higher aspect ratio nanorods prepared in the absence of AgNO3. The growth conditions were optimized by varying the concentrations of reactants, mainly surfactants and gold seed. The formation, and the stability of the synthesized nanorods were characterized by VIS-NIR absorption spectra and electron microscopy.