6,6-ionene-stabilized gold nanoparticles: synthesis, characterization and prospects of use

Synthesis of new polycation-stabilized gold nanoparticles was performed by the borohydride approach. 6,6-ionene was used as a polycationic stabilizer. The influence of several factors such as the acidity, the Au:ionene ratio and the concentration of sodium borohydride during the synthesis were investigated. The key role of the amount of HCl added during the synthesis on the behaviour of the products in time was shown. Optimal conditions for the synthesis were chosen. The prepared gold nanoparticles were characterized by surface plasmon resonance band at 520 nm. Their average diameter is 16 nm. Apart from spherical (73%), there were pentagonal (14%), hexagonal (7%), triangular (4%) and cylindrical (2%) nanoparticles. These particles were stable in solution for at least four month.s Aggregative stability of the nanoparticles in the presence of different inorganic anions was tested. It was shown that the most aggregative effect was produced by sulfate, which reveals the prospects for use of ionene-stabilized gold nanoparticles for the selective detection of sulfate. These nanoparticles can be easily adsorbed on hydrophobic C-8-silica, which may offer the way to new solid-phase nanomaterials for recovering and separation.