Characterization of Gold Nanoparticles Synthesized Using Sucrose by Seeding Formation in the Solid Phase and Seeding Growth in Aqueous Solution

Abstract

A simple method for safely preparing Au nanoparticles of a few to 20 nm in diameter has been developed on the basis of chemical reduction of HAuCl4 with glucose and fructose produced by the acidic hydrolysis of sucrose. The method includes seeding formation in the solid mixture of HAuCl4 and sucrose via heat treatment at 70−100 °C and seeding growth after dissolving the heated mixture in water at room temperature. The X-ray photoelectron spectroscopic analyses of the HAuCl4−sucrose mixture heated at 80 °C for 15 min confirmed the presence of Au(0) and Au(I) in the sample. Both the X-ray diffraction and UV−vis spectroscopic measurements of the heated mixture suggest the very small sizes of gold clusters in the sample. The particle growth in the aqueous solution was followed by in-situ monitoring of the surface plasmon band with a time-resolved UV−vis spectrometer. The size and size distribution of the resulting nanoparticles were measured by both dynamic light scattering and transmission electron microscopy. Electrophoresis combined with visible spectroscopy confirmed that gold nanoparticles in the aqueous solution carried negative charges that resulted from carboxylic acid groups bound to the particles, based on the infrared spectroscopic measurement.