Impact of strong and weak lipid-protein interactions on the structure of a lipid bilayer on a gold electrode surface.

A lipid bilayer deposited on an electrode surface can serve as a benchmark system to investigate lipid-protein interactions in the presence of physiological electric fields. Recoverin and myelin-associated glycoprotein (MAG) are used to study the impact of strong and weak protein-lipid interactions on the structure of model lipid bilayers, respectively. The structural changes in lipid bilayers are followed using electrochemical polarization modulation infrared reflection-absorption spectroscopy (PM IRRAS).

Structural analysis of HS(CD(2))(12)(O-CH(2)-CH(2))(6)OCH(3) monolayers on gold by means of polarization modulation infrared reflection absorption spectroscopy. progress of the reaction with bromine.

A self-assembled monolayer (SAM) on gold was formed with specifically perdeuterated hexaethylene glycol-terminated alkanethiol HS(CD(2))(12)(O-CH(2)-CH(2))(6)OCH(3) (D-OEG). The structure of the d-alkane and the oligoethylene glycol (OEG) parts of the molecule in a SAM was studied by means of polarization modulation infrared reflection absorption spectroscopy. The D-OEG monolayers are highly ordered and exist in a crystalline phase.

Application of thin titanium/titanium oxide layers deposited on gold for infrared reflection absorption spectroscopy: structural studies of lipid bilayers.

Ultrathin titanium layers when deposited on the surface of gold can be successfully applied for infrared reflection absorption spectroscopy (IRRAS) investigations. It was shown that the reflectivity, the phase shift, and the mean square electric field of the p- and s-polarized IR radiation in up to 20 nm thick titanium layers covered with a 3-4 nm thick layer of native oxide are comparable to those of the air/gold interface. The surface selection rule is fulfilled.

Microelectrochemical modulation of micropatterned cellular environments.

Patterned cell cultures obtained by microcontact printing have been modified in situ by a microelectrochemical technique. It relies on lifting cell-repellent properties of oligo(ethylene glycol)-terminated self-assembled monolayers (SAMs) by Br2, which is produced locally by an ultramicroelectrode of a scanning electrochemical microscope (SECM). After Br2 treatment the SAM shows increased permeability and terminal hydrophobicity as characterized by SECM approach curves and contact angle measurements, respectively.