New directions and challenges in electrochemistry - Bioelectrochemistry atmetal/water interfaces

Some aspects of bioelectrochemistry at metal \ water interfaces which may p rovide useful information on the role played by biomolecules in biological processes are overviewed and assessed. Electrochemical reactions of water-s oluble redox proteins, either immobilized on bare or functionalized electro de surfaces or free to diffuse toward the electrode, are briefly reviewed. The preparation and architecture of metal-supported biomembrane models, bot h noncovalently and covalently attached to the metal surface, are described . The structure of self-organized phospholipid monolayers interposed betwee n the metal surface and the aqueous phase is examined, with particular rega rd to the ionizable groups and the surface dipole potential of their polar heads. Particular attention is focused on the preparation of biomembrane mo dels capable of incorporating integral proteins in a functionally active st ate. The use of experimental models of biomembranes for investigating the f unction of integral proteins, either incorporated in biomembrane fragments or proteoliposomes adsorbed on metal-supported mixed alkanethiol \ lipid bi layers, or directly incorporated in metal-supported lipid bilayers, is desc ribed. The potential of metal-supported lipid bilayers with a hydrophilic ' spacer' interposed between the metal surface and the bilayer for fundamenta l studies on the function of integral proteins and for reliable and rapid d rug screening is emphasized. (C) 2001 Elsevier Science B.V. All rights rese rved.