Self-assembled organic templates for the selective adsorption of gold nanoparticles into confined domains

A simple procedure for the fabrication of submicron-sized functional organic templates is demonstrated. Native silicon samples are partially coated in millimolar octadecyltrichlorosilane (OTS) solutions. After coating, atomic force microscopy (AFM) reveals islands with diameters ranging from 0.6 to 1 μm. The hydrocarbon chains of the self-assembled silane entities within these islands subsequently are chemically functionalized following a robust preparation scheme. X-ray photoelectron spectroscopy (XPS) and water contact angle measurements were used for characterization. After functionalization, alkylsiloxane islands provide a versatile means to direct the deposition of nanoscopic components. In particular, citrate-stabilized gold nanoparticles (d = 16 ± 2 nm) are shown to selectively adsorb onto aminated islands, whereas adsorption on areas between these islands is negligible.