Gutachten zur Umweltbiologie

Aquatic Ecotoxicity Effects of Gold Nanoparticles with Irregular Shapes

Tariq Altalhi

Aquatic Ecotoxicity Effects of Gold Nanoparticles with Irregular Shapes

A simple chemical route, based on a modified polyol process, is used to synthesize mono-disperse triangular gold nanoprisms (Tr-AuNPs) in triethylene glycol (TREG) with polyvinyl-pyrrolidone (PVP) as capping agent. Both the solvent and the surfactant in the solution play important roles in the formation of the Tr-Au NPs. Shape, size and optical properties of the particles were tuned by changing the molar ratio of PVP to metal salts. The formation of such large, single-crystal Tr-Au NPs is explained by the preferential adsorption of some species of molecules from the solution onto the {111} planes of Au nuclei. The anisotropy in the nanoparticles’ shape shows strong localized surface plasmon resonance (SPR) in the near infrared region of the electromagnetic spectrum. These nanostructures may be used in areas that include photonics, optoelectronics, optical sensing and also for inducing hyperthermia in tumors. For this reason, the ecotoxicological effects of the Tr-Au NPs and their interactions with marine organisms were also studied in this work. It was found that Tr-Au NPs don’t seem to have a large effect on the non-target marine organism R. decussatus. Indeed, no significant modification (p>0.05) was observed after 2 days on the glutathione-S-transferase activity of the clams exposed to Tr-Au NPs when compared to the control, both in the gill and the digestive glands.