ELECTROCHEMICAL PROPERTIES OF PYROLYTIC-GRAPHITE ELECTRODES MODIFIED THROUGH ADSORBED PROTEINS

The adsorption of various proteins at the PG electrode has been studied electrochemically using the film transfer technique. When the transfer is performed into probe systems such as Fe(CN) 3- 4-6 or spinach ferredoxin, three possibilities exist: inhibition, no effect, promotion. The different factors which may govern the properties of these modified electrodes have been examined: the pH of the solution investigated, the pH at which the PG electrode was treated, the polarization of the PG electrode, the coadsorption of two proteins. A special attention has been drawn on the promotion of slow electrochemical systems such as ferredoxins or flavodoxins when using the PG electrode modified by adsorbed Desulfovibrio vulgaris cytochrome c3. A pattern of behaviour has been proposed by taking into account several factors: coulombic interactions, hydrophobicity, the effect of electric field on adsorbed molecules. © 1990.