In Situ Electrochemistry of Cytochrome c at Lipid Monolayer-Modified Electrodes at the Air-Water Interface

Interaction of cytochrome c with monolayers of dipalmitoylphosphatidic acid (DPPA), dipalmitoylphosphatidylcholine (DPPC), and dioctadecyldimethylammonium poly(styrenesulfonate) (2C₁₈N⁺PSS⁻) has been investigated on the basis of the surface pressure-area (π-Α) and the in situ electrochemical measurements at the air-water interface. Results in the π-Α and the electrochemical measurements indicate that the electrostatic interaction between cytochrome c and the lipid monolayers plays an important role for the electron transfer reaction of cytochrome c at the lipid monolayer modified electrodes. Furthermore, the electrode reaction of cytochrome c is affected by the packing and stability of lipid monolayers on the electrode surface.