Voltammetric and visual evidence of adsorption reactions at the liquid-liquid interfaces supported on a metallic electrode

A three electrode configuration consisting of an aqueous drop containing a redox couple of Fe2+/Fe3+ or IrCl62-/IrCl63- attached onto the surface of a platinum electrode and immersed into an organic electrolyte solution was apply to evaluate the adsorption-desorption processes associated with L-alpha-dipalmitoyl phosphatidylcholine (DPPC) interfacial complex formation. It has been observed that a significant deformation of the aqueous droplet immersed into the solution occurs in the presence of the phospholipid at potentials where the adsorption occurs. Nevertheless as the potential increases, the desorption of charged complexes of DPPC takes place, resulting in a potential-dependent drop shape phenomenon. (C) 2011 Elsevier Ltd. All rights reserved.