title: Directed assembly of single colloidal gold nanowires by AFM nanoxerography.
abstract: Ultrathin gold nanowires (NWs) dispersed in hexane were prepared by chemical reduction of HAuCl4 in oleylamine, along with nanospheres (NSs), side products of the reaction. X-ray photoelectron spectroscopy and small-angle X-ray scattering evidenced a stabilization of these nano-objects by oleylammonium chloride surfactants. The directed assembly of these nano-objects on surfaces was performed by atomic force microscopy (AFM) nanoxerography in a few seconds. Selective assembly of gold NWs only occurred on positively charged patterns, while NSs assembled more specifically on the negatively charged ones. This sorting suggests that the strong electric field generated by the charge patterns induced a negative effective charge on the gold NWs and a weak positive effective charge on the NSs. Such difference could be explained by the ion organization at the colloid surface, monolayered in the case of NWs, and bilayered in the case of NSs. By adjusting the design of the positive patterns and the experimental conditions of development, single gold nanowires were successfully assembled by AFM nanoxerography on predefined sites of surfaces without damaging them, opening the way for future electrical and mechanical characterizations.
authors.affiliation: †Université de Toulouse, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), UMR 5215 INSA-CNRS-UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Moutet
authors.affiliation: †Université de Toulouse, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), UMR 5215 INSA-CNRS-UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France.
authors.forename: Lise-Marie
authors.initials: LM
authors.lastname: Lacroix
authors.affiliation: †Université de Toulouse, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), UMR 5215 INSA-CNRS-UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Robert
authors.affiliation: ‡Laboratoire de Physique de Solides, UMR 8502, Bat. 510, Université Paris-Sud, F-91405 Orsay, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Impéror-Clerc
authors.affiliation: †Université de Toulouse, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), UMR 5215 INSA-CNRS-UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Viau
authors.affiliation: †Université de Toulouse, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), UMR 5215 INSA-CNRS-UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Ressier