title: Differential adsorption of gold nanoparticles to gold/palladium and platinum surfaces.
abstract: Integration of molecule-capped gold nanoparticles (AuNP) into nanoelectronic devices requires detailed knowledge about the AuNP-electrode interface. Here, we report the pH-dependent adsorption of amine or carboxylic acid-terminated gold nanoparticles on platinum or gold/palladium (30% Pd) alloy, respectively. We synthesized amine-terminated AuNP, applying a new solid phase supported approach, as well as AuNP exhibiting carboxylic acid as terminal groups. The pH-induced agglomeration of the synthesized AuNP was investigated by UV-vis, DLS, and ζ-potential measurements. Depending on the pH and the ionic strength of the AuNP solution a preferential adsorption on the different metals occurred. Thereby, we demonstrate that by choosing the appropriate functional group and adjusting the pH as well as the ionic strength a directed binding can be achieved, which is an essential prerequisite for applications of these particles in nanoelectronics. These findings will pave the way for a controlled designing of the interface between molecule-capped AuNP and metallic electrodes for applications in nanoelectronics.
authors.affiliation: Institute of Inorganic Chemistry and JARA - Fundamentals of Future Information Technologies, RWTH Aachen University , 52074 Aachen, Germany.
authors.forename: Corinna
authors.initials: C
authors.lastname: Kaulen
authors.forename: Melanie
authors.initials: M
authors.lastname: Homberger
authors.forename: Svenja
authors.initials: S
authors.lastname: Bourone
authors.forename: Ninet
authors.initials: N
authors.lastname: Babajani
authors.forename: Silvia
authors.initials: S
authors.lastname: Karthäuser
authors.forename: Astrid
authors.initials: A
authors.lastname: Besmehn
authors.forename: Ulrich
authors.initials: U
authors.lastname: Simon