Liquid chromatography—electrochemical detection of ferro- and ferricytochrome c at a chemically modified gold electrode

LCEC determination of the copper protein ceruloplasmin in human serum at a polyaniline chemically modified electrode

“…Among these, the best example is provided by the family of pyridinemodified gold electrodes, which have been shown to give nearly reversible redox waves for cytochrome c (molecular weight 12,400) [ll-141. One of these electrodes, prepared by adsorbing 4,4'-dithiodipyridine onto a polyvinylferrocene-treated gold surface, has been used in LCEC to determine both the ferri-and ferro-forms of the protein at the picomole level [14]. More recently, a CME formed by adsorption of the electrocatalyst methylene blue onto a graphite surface has been reported to give an excellent LCEC response for myoglobin (molecular weight 17,000) and hemoglobin (molecular weight 64,500) at very modest values of applied potential [IS].…”