Retracted: Temperature effect on synthesis of amphiphilic gold nanoparticles

We investigate the effect of temperature on synthesis of amphiphilic gold nanoparticles (AuNPs) via ligand exchange. The AuNPs surface was functionalized with both hydrophilic and hydrophobic ligands via ligand exchange reactions. The fractions of the hydrophilic and hydrophobic ligands on the AuNPs surface at different temperatures (20 ˚C, 40 ˚C and 60 ˚C) were determined by electrostatic titrations by addition of positively charged surfactants. The AuNPs used were well-dispersed as individual NPs in water with pH ~ 11, confirmed by transmission electron microscopy (TEM) and UV-Vis spectroscopy. When the temperature increases, the hydrophobic ligand coverages on the AuNPs surface also increase. In this paper, we demonstrate that AuNPs surface properties such as hydrophobic and hydrophilic ligand ratios can be tuned by controlling the temperature during ligand exchange.