XPS Examination of the Chemical Composition of PEGMUA?Coated Gold Nanoparticles

A surface chemical analysis of 12 nm diameter gold nanoparticles (AuNPs) coated with polyethylene glycol (PEG)-11-mercaptoundecanoic acid (MUA) is performed by means X-ray photoelectron spectroscopy (XPS). For this purpose, the PEGMUA-coated AuNPs are deposited using two different deposition techniques, drop-casting or spin-coating, on a thin-film carbon substrate. The measurements show that present in +I oxidation state due to synthesis process AuNPs, and Au(0) state. Carbon oxygen contaminations detected both coating While sputtering sample argon enables removal contaminations, it also removes part surface. methods, however, do not cause any structural changes nanoparticles.