Gold Nanoparticles Stabilized by Glycodendrimers: Synthesis and Application to the Catalytic Reduction of 4-Nitrophenol.

Air-stable gold nanoparticles stabilized by glycodendrimers (AuDSNs) in water were prepared in the presence of a reducing agent, NaBH₄. A UV/Vis spectroscopy study demonstrates that no spontaneous reduction of Au³⁺ ions occurs in the presence of glycodendrimers. The AuDSNs were characterized by UV/Vis spectroscopy and transmission electron microscopy (TEM). TEM images show that the AuDSNs were very small (average diameter: 2.6 nm). The catalytic activity of these AuDSNs was evaluated for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH₄ monitored by UV/Vis spectroscopy. Studies of the reduction reaction reveal that the rate constant depends on the concentration of 4-NP. [ABSTRACT FROM AUTHOR]