Enhanced Stability of Thiolate Self-Assembled Monolayers (SAMs) on Nanostructured Gold Substrates

EMILIANO CORTÉS; ALDO A. RUBERT; GUILLERMO A. BENITEZ; PILAR CARRO; MARIA E. VELA; ROBERTO C. SALVAREZZA

LANGMUIR

ACS Publications

Año: 2009 p. 5661 - 5666

0743-7463

Degradation of thiolate self-assembled monolayers (SAMs) in ambient conditions and liquid environments seriouslylimits the fabrication of thiol-based devices. Here, we demonstrate that nanostructured gold exhibits higher resistance toSAM degradation and increased electrochemical stability against thiolate desorption in relation to polycrystallinepreferred oriented Au(111). The increased stability can be related to the presence of a large number of defects, such asadatoms, vacancies, and steps where the thiolate binding energy is stronger than at terraces. The nanostructured Au is aninteresting platform because it can be easily prepared, has surface enhanced Raman spectroscopy (SERS) activity, andexhibits a high signal/noise ratio for amperometric detection because of its large real surface area.