Morphology-Controlled Versatile One-Pot Synthesis of Hydrophobic Gold Nanodots, Nanobars, Nanorods, and Nanowires and Their Applications in Surface-Enhanced Raman Spectroscopy

Abstract

Many previously reported syntheses of gold nanoparticles required lengthy reaction times, complicated operations, high temperatures, or multi-step manipulations. In this work, a morphology-controlled versatile one-pot synthesis of hydrophobic gold nanodots, nanobars, nanorods, and nanowires has been developed. A series of gold nanomaterials ranging from round nanodots, short nanobars, and long nanorods to ultrathin and ultralong nanowires (diameter <2 nm, length >2 μm) have been readily prepared by simply adjusting the feeding ratio of chloroauric acid to oleylamine, oleic acid, and triphenylsilane. The silk-like ultralong and ultrathin nanowires were found to have a single crystalline structure and may have significant potential applications in microelectronics and biosensors. Large sizes of gold spherical nanoparticles were obtained from gold nanodots via a seed-mediated growth approach. These nanoparticles and ultralong nanowires showed excellent surface-enhanced Raman scattering (SERS) activity in organic solvents and, therefore, were employed as efficient organic-soluble SERS substrates for the detection of hydrophobic food toxicants, such as 3,4-benzopyrene, and carcinogens, such as benzidine.

Keywords

• synthesis
• gold nanodots
• nanobars
• nanorods
• nanowires
• surface-enhanced Raman spectroscopy