STUDIES OF PROTEIN-ELECTRODE INTERACTIONS BY ORGANOSILYL DERIVATIZATION OF PYROLYTIC-GRAPHITE ELECTRODES

The authors studied the effects, on protein electrochemistry, of selective derivatisation of C-O functionalities with the blocking groups Me//3Si- and Ph//3Si-. Comparisons are made between the behaviour of two proteins, cytochrome c and azurin, and that of three small inorganic redox couples, at native and modified electrode surfaces. The results give a simple demonstration of the increased interfacial specificity displayed by the biological macromolecules. It is found that the loss of cytochrome c electroactivity must arise from modification of electrode surface functionalities which are essential for interaction with the protein. The observation of virtually unchanged kinetics with azurin shows furthermore that the interactive requirements of the two proteins are very different.