Enhanced cellular uptake of amphiphilic gold nanoparticles with ester functionalityElectronic supplementary information (ESI) available: Synthesis of ligands, preparation of AuNPs, and experimental details. See DOI: 10.1039/c3cc48532c

Gold nanoparticles (AuNPs) coated with ester-headed or ether-headed PEG ligands were synthesized. Ester-headed AuNPs, but not ether-headed, were transferred from the organic phase (CH 2 Cl 2 ) to the alkali aqueous phase, indicating that the hydrolysis of the ester moiety triggered the phase transfer of the AuNPs. We found that AuNPs with ester-headed ligands (ester-AuNPs) were internalized into HeLa cells at a greater level than were ether-headed AuNPs. Gold nanoparticles (AuNPs) coated with ester-headed or ether-headed PEG ligands were synthesized.