It has been demonstrated that patterned two-dimensional silver nano-arrays can be readily prepared by forming initially mixed self-assembled monolayers (SAMs) comprised of methyl and carboxylic groups and then allowing the selective growth of silver at the carboxylic acid groups. Microcontact printing was done to prepare patterned SAMs on a gold film, which is a method that uses an elastomeric stamp with micrometer-dimensional features to transfer organic thiols onto the metal surfaces. A modified mirror reaction was employed to prepare a silver nanostructure. The silver nanoparticles were selectively grown mainly on the regions exposed to the carboxylic groups of the patterned SAM gold substrates. Methanol was used as a reductant with high selectivity and atomic economy, and six silver ions can be reduced by only one methanol molecule. The morphologies of the silver nanostructures were confirmed with atomic force microscopy and scanning electron microscopy. The optical properties of the silver nanostructures were studied with Raman spectroscopy.

Key words: self-assembled monolayer, patterned 2-dimensional silver nano-array, selective reduction, microcontact printing, methanol