Photochemical reactions of thiol-terminated self-assembled monolayers (SAMs) for micropatterning of gold nanoparticles and controlled surface functionality

Abstract

This paper reported a facile method for the patterning of gold nanoparticles (AuNPs) on SiO2/Si by combining photochemical reaction and self-assembly techniques, and the conversion of surface functionality through thiol-ene click chemistry. The oxidation of terminal thiols in self-assembled monolayer of (3-mercaptopropyl)trimethoxysilane upon exposure to 254nm UV light under ambient atmosphere was investigated. Chemically well-defined microstructures were obtained by UV irradiation through a mask, and subsequent immersion of the substrate into a dispersion of AuNPs resulted in site-specific assembly of AuNPs via Au–S covalent bond in the unexposed area. Thiol-ene “click” reaction between surface thiol-group and alkene-containing molecules under illumination of 365nm UV light was also demonstrated. X-ray photoelectron spectroscopy study indicated the successful conversion of surface functionality.