(Keynote) Surfactant and Halide Control in Gold Nanorod Synthesis

Abstract

Gold nanorods have been of continuing interest to many scientists due to their brilliant optical properties that are dictated by particle shape. Nanorods exhibit both transverse and longitudinal plasmon bands that are tunable from the visible into the near-infrared. Applications areas include plasmon-based sensors, diagnostics, imaging agents, and even photothermal therapeutics due to reasonably efficient light-to-heat conversion. The primary synthesis of these materials starts with a gold salt, and various reduction steps with various reducing agents, in the presence of particular surfactants and ions, do produce gold nanorods of tunable aspect ratio; yet the details of the synthetic steps and the "true" source of the symmetry-breaking anisotropy to produce rods instead of spheres are still the subject of debate. In this talk we will examine the state of the art in gold nanorod synthesis, including recent work that used a design-of-experiment multifactorial approach to gain deeper mechanistic insights into synergistic effects between the various reagents in the synthesis.