Human sulfite oxidase electrochemistry on gold nanoparticles modified electrode

Miniature direct electron transfer based sulphite/oxygen enzymatic fuel cells

“…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.…”

The Electrically Wired Molybdenum Domain of Human Sulfite Oxidase is Bioelectrocatalytically Active

“…[9,17] The formal potential of the heme b 5 domain was determined by cyclic voltammetry by using the isolated domain and a gold electrode modified with a positively charged self-assembled monolayer. At -0.1 V, the polymer could theoretically oxidize both domains.…”

“…[8][9][10][11] In contrast, in bacterial sulfite dehydrogenase (SDH), heme and Moco are located on separate subunits, and turnover does not require the repositioning of these subunits. [12] From measurements of chicken sulfite oxidase (cSO) on amino-functionalized electrodes, the heme domain has been identified as a relay for electrocatalysis.…”

“…[8] The introduction of nanoparticles further enhanced the efficiency of the unmediated bioelectrocatalytic response. [9] However, the only cofactor that could actively interact with the electrode was heme b 5 . The mechanism of cSO was also electrochemically studied with organic electron acceptors.…”

Ionic liquid-assisted morphosynthesis of gold nanorods using polyethyleneimine-capped seeds

“…PEI, which provides a high density of cationic amine moieties, acts as a polydentate capping layer of the gold surface therefore accounting for the high stability of these small particles. Interestingly, when similar Au seeds are prepared in 1-ethyl-3-methylimidazolium ethylsulfate (emimEtSO 4 ), 37 the seed stability is significantly reduced pointing to a complementary stabilizing effect of longer alkyl chain of the anions. Since both emimHexSO 4 and PEI are hydrophilic, these particles can directly act as seeds for the aqueous synthesis of Au NR.…”