Synthesis of gold nanoparticles with glycosides: Synthetic trends based on the structures of glycones and aglycones

A new, room temperature synthetic method for gold nanoparticles from auric acid with glycosides as reducing agents in aqueous NaOH is presented. As a mechanistic study of the oxidation sites on the glycosides, eight sugar-containing reductants (glycoside, glucose, glucuronic acid) have been tested in the synthesis of gold nanoparticles to determine their trends based on the structures of glycones and aglycones. As a result of the comparison among the eight sugar-containing reductants, it was determined that C-6 of glycosides is oxidized to a carboxylic acid during the reduction of auric acid. To detect the oxidized compounds of the glycosides, the reaction mixtures were monitored by ¹³C NMR. Among the eight sugar-containing reductants, phenyl β-d-glucoside generated the highest synthetic yield of mono-dispersed, round gold nanoparticles (13.15 ± 1.30 nm, 99.7% yield).