Layer-by-layer self-assembled multilayers of polyelectrolytes and gold nanoparticles

NANCY FERREYRA, MANUEL LOPEZ TEIJELO AND PIERRE LABBÉ

Il Ciocco, Luca, Italia

Congreso; Gordon Research Conference, Ion-Containing Polymers; 2005

Nanoparticles based nanostructured films are currently under intense investigation since they offer the potential for applications in various fields such as semiconductors, molecular electronics, photovoltaic, chemical and biological sensing and catalysis [1]. The assembly of metal nanoparticles into bi or tri dimensional superstructures has been reported using several kinds of linkers. Electrostatically layer-by-layer (LbL) growth of polyelectrolyte/gold nanoparticle films has also been reported [2] using the electrostatic method popularised by Decher [3]. The structure properties of these films depend on the polyelectrolyte characteristic, the nanoparticle morphology as well as the experimental conditions for self-assembling. In this work we describe the electrostatic LbL assemblies of negatively charged gold nanoparticles (NP) with a viologen-based cationic redox polyelectrolyte called polyviologen (PV) [4]. The growing of PV-NP assemblies was demonstrated by in situ UV-Vis and electrochemical experiments. For this propose, the multilayers were growth up on the top of a quartz or a gold modified surface respectively. The effects of NP size, the polymer charge density and the adsorption time for NP were evaluated. In addition, ellipsometric studies were performed to follow step by step the film thickness increase and to determine the corresponding optical properties.