“…Cytc can be replaced by an electrode, either by using mediators or via direct electron transfer (DET), and SOx can hence be used to make both second and third generations enzymatic sensors (Pundir and Rawal, 2013;Spricigo et al, 2010). DET between SOx and different electrodes have been reported (Elliott et al, 2002;Ferapontova et al, 2003;Frasca et al, 2012;Sezer et al, 2010), where efficient ET can be achieved by employing cationic surface modifiers to promote adsorption of SOx in a suitable orientation.…”