CONICET | Buscador de Institutos y Recursos Humanos

One way to achieve surfaces with controlled and adjustable properties is to modify them with well-defined molecular films. In particular, the self-assembly of thiols on gold is a method that provides a convenient and simple way to create a thin and very ordered molecular film with adapted chemical and electrical properties. On the other hand, heavy metal ions are common pollutants in water and can cause severe health damage. They are not biodegradable and can be bioaccumulated.1In this work, the affinity of the copper (II) ion to self-assembled monolayers on bifunctional thiol on gold was studied. The thiols chosen exposed hydroxyl and carboxylic acid groups. Infrared spectroscopy of absorption reflection with Polarization modulation and X-ray photoelectronic spectroscopy was used to the physicochemical characterization of the structure and the structure-function relationship of the modified surfaces. And also their interaction with the Cu2+ ion and the influence of the alkyl chain length. PM-IRRAS gave information about the functional groups present on the surface, their environment, and how they were modified with the presence of the copper ion. Additionally, XPS provided information on the presence of copper in all tested monolayers and on the elementary relationships between S: Cu at each step of the treatment.Results showed that all of the SAMs retained similar amounts of copper and that for short chain thiols, the copper was electrically connected to the electrode. Furthermore, upon interaction with the copper solution, most of the carboxylic acid moieties deprotonated, forming a complex with the copper cation.(1) Brewer, G. J. J Am Coll Nutr , 2009, 28 (3), 238?242