![Figure 3 (A) Cyclic voltammetry of cytochrome c a tin doped indium oxide optically transparent electrode after purification. Solutions contained [Cyt c]=73 mM, 0.21 M Tris and 0.24 M cacodylic acid, pH 7.0, electrode area=0.71 cm . Potential scan rates in](https://images.tandf.co.uk/common/jackets/crclarge/978082470/9780824707316.jpg "Figure 3 (A) Cyclic voltammetry of cytochrome c a tin doped indium oxide optically transparent electrode after purification. Solutions contained [Cyt c]=73 mM, 0.21 M Tris and 0.24 M cacodylic acid, pH 7.0, electrode area=0.71 cm . Potential scan rates in")
ABSTRACT
An earlier extensive study by Edmund Bowden had demonstrated the importance of using electrodes with hydrophilic surfaces in electrochemical studies of cytochrome c [46]. At that time the cyclic voltammetry of cytochrome c at gold was found to decay with time, but the response could be restored on cleaning the electrode in a soft hydrogen flame that rendered the surface hydrophilic. It is now clear that the lack of stability was due to these samples being chromatographically purified, lyophilized, and then stored at −4°C for later use. This produced oligomeric forms of cytochrome c that fouled metal electrode surfaces. Metal surfaces are more active to adsorption of protein impurities than tin oxide and indium oxide and more easily fouled by protein adsorption.
