Electrochemistry of mercury supported phospholipid monolayers and bilayers

The field of supported monolayers and bilayers on mercury (Hg) electrodes has been reviewed. The paper has focused initially on the development of the area from the classical ideas and experiments of interfacial electrochemistry in particular the adsorption of organic compounds on Hg. This development includes the structure and properties of water soluble synthetic and biological polymers at Hg/electrolyte interfaces and investigations of the adsorption of insoluble compounds specifically lipids at the Hg/electrolyte interface. The review then discusses the applications of the monolayer on the Hg membrane model to understand better biological membrane structure and function including the following areas: phospholipid behaviour in electric field, monolayer permeability to ions, gramicidin ion channel properties, electron and proton transfer to ubiquinone-10 and, biosensor applications. Finally the most recent developments of the model are detailed including advances in the impedance analysis of ultra-thin films, the transformation of the monolayer to a more relevant bilayer model and the ruggedisation of the model for on-line toxicity testing.Major recent advances during 2009–20101.Robust platform for on-line biomembrane active compound and nanomaterial screening.2.Model relating impedance of thin films on electrodes to their structure and properties.3.Single ion channel activity in phospholipid bilayer on Hg film microelectrode.4.Full development of bilayer system to mimic biological membrane function in bilayers.

Graphical AbstractFrom top left hand corner clockwise shows: a) deposition of phospholipids at gas/electrolyte interface on HMDE, b) configuration of phospholipid molecules on the Hg surface at the PZC following deposition, c) effect on the phospholipid monolayer configuration when a potential is applied and increased, d) flow cell used for deposition of phospholipid monolayers on Pt/Hg microelectrodes on Si wafer, and e) current potential plots from different phospholipid monolayers on the Pt/Hg microelectrodes recorded by RCV.Figure optionsDownload high-quality image (46 K)Download as PowerPoint slideResearch Highlights
► From interfacial electrochemistry to phospholipid monolayers on Hg.
► Phospholipid monolayers on Hg.
► Phospholipids in electric field.
► Ionic permeability.
► Gramicidin, Ubiquinone-10.
► Biosensors.
► Charge properties.
► Recent developments.
► Impedance studies.
► Monolayer to bilayer.
► Model ruggedisation.