Growth of Colloidal Gold Nanostars and Nanowires Induced by Palladium Doping

Abstract

Gold-palladium nanocrystals with starlike shapes and high aspect ratio nanowires were grown in a surfactant solution. The incorporation of palladium into the growing gold nanostructures induced nanowire formation with high yield. Kinetic control of the metal deposition rate through tuning of the pH value to about 5 was crucial for the nanowire growth. The nanostructures were characterized by high-resolution electron microscopy and energy-dispersive X-ray spectroscopy. The Au-Pd nanowires were deposited on functionalized silicon wafers.

Plasmon-Resonant Nanoparticles and Nanostars with Magnetic Cores: Synthesis and Magnetomotive Imaging

“…The growth of NSTs was essentially complete within 15 minutes and the final nanostructures were stable for at least a month at room temperature, following the removal of excess CTAB (see below). HRTEM analysis along individual NST spines revealed the presence of multiple twinning defects and overall growth along the (111) direction, similar to that observed in previous analyses 36. Extinction spectra were characterized by strong NIR bands with a shoulder starting from 700 nm, corresponding to the NSTs’ anisotropic projections 37.…”

Recent Advances in the Liquid‐Phase Synthesis of Metal Nanostructures with Controlled Shape and Size for Catalysis

“…Polycrystalline Au nanowires were formed with a preferential growth of the (111) facet (94). Growth of colloidal gold nanowires (along with nanostars) was shown to be induced by Pd doping (95). Using a combined solution of aqueous HAuCl 4 and triethylamine at room temperature, gold threads were obtained.…”

Gold Nanoprobes for Theranostics

“…By assuming a star morphology, gold nanocrystals increase in proportion to the exposed {111} planes and have low surface energy that could be highly useful for creating stable and biologically active surfaces. Gold nanostars exhibit high plasmonic resonance due to juxtapositioning of the tips that radially emerge from the core making these structures useful for imaging by dark field microscopy, SERS and plasmonics [33–37]. …”

“…Gold nanostars [35–37] exhibit a short wavelength plasmon band (nanostar core) in the mid-visible region and a long-wavelength plasmon band (nanostar arms), which appears following nucleation and evolves over time in the NIR region [35]. The short and long plasmon peaks are attributed to the plasmon modes associated with the inner core and branch tips, respectively.…”