Permselective-membrane pyrolytic graphite electrode for the study of microvolumes of [2Fe-2S] ferredoxin.

A permselective-membrane pyrolytic graphite electrode was used to study the electrochemistry of [2Fe-2S] ferredoxin entrapped between the membrane and the graphite surface, in the presence of poly(l-Lysine). Factors influencing the electrode response [such as the concentration of poly(l-lysine), ionic strength and pH] were explored. The analytical performance of this permselective-membrane electrode, which allows 20 pmol of ferredoxin to be detected, was examined.