Low-energy ion scattering: Determining overlayer thickness for functionalized gold nanoparticles

TitleLow-energy ion scattering: Determining overlayer thickness for functionalized gold nanoparticles
Publication TypeJournal Article
Year of Publication2013
AuthorsRafati A., R. Veen ter, Castner D.G
JournalSurface and Interface Analysis
Date PublishedNov
ISBN Number0142-2421
Keywordsauger-electron-spectroscopy, biology, characterization, delivery, flat, gold nanoparticles, growth, hs-leis, Nanotechnology, overlayer thickness, ray photoelectron-spectroscopy, self-assembled monolayers, sessa, simulation, surfaces, xps

With the widespread use of engineered nanoparticles for biomedical applications, detailed surface characterization is essential for ensuring reproducibility and the quality/suitability of the surface chemistry to the task at hand. One important surface property to be quantified is the overlayer thickness of self-assembled monolayer (SAM) functionalized nanoparticles, as this information provides insight into SAM ordering and assembly. We demonstrate the application of high sensitivity low-energy ion scattering (HS-LEIS) as a new analytical method for the fast thickness characterization of SAM functionalized gold nanoparticles (AuNPs). HS-LEIS demonstrates that a complete SAM is formed on 16-mercaptohexadecanoic acid (C16COOH) functionalized 14 nm AuNPs. HS-LEIS also experimentally provides SAM thickness values that are in good agreement with previously reported results from simulated electron spectra for surface analysis of X-ray photoelectron spectroscopy data. These results indicate HS-LEIS is a valuable surface analytical method for the characterization of SAM functionalized nanomaterials. Copyright (c) 2013 John Wiley & Sons, Ltd.