Seed-mediated growth of jack-shaped gold nanoparticles from cyclodextrin-coated gold nanospheres

Abstract

Branched gold nanoparticles were prepared by a seed-mediated approach using per-6-thio-6-deoxy-β-cyclodextrin capped gold nanospheres as seeds and a growth medium similar to those commonly employed to prepare gold nanorods, containing AgNO₃, ascorbic acid and cetyltrimethylammonium bromide. Novel jack-shaped gold nanoparticles (102–105 nm) were obtained at a specific range of Ag⁺ ion concentrations (62–102 μM). The crystalline structure of these nanoparticles was confirmed by high-resolution transmission electron microscopy. The influence of the perthiolated β-cyclodextrin on the successful preparation of gold nanojacks was demonstrated. The jack-shaped gold nanoparticles showed strong absorption in the near infrared region and excellent catalytic activity for the electrochemical oxidation of H₂O₂.