Detection of hydrogen peroxide produced during the oxygen reduction reaction at self-assembled thiol-porphyrin monolayers on gold using SECM and nanoelectrodes.
Porphyrin molecules were immobilized on polycrystalline gold and glassy carbon by coordinating cobalt(II) 5,10,15,20-tetraphenyl-21H,23H-porphine to a 4-aminothiophenol self-assembled monolayer. The resulting electrocatalytic activity of the metalloporphyrin-modified substrates with regard to the oxygen reduction reaction was characterized by means of cyclic voltammetry and scanning electrochemical microscopy (SECM) using nanoelectrodes of well-defined geometry. From substrate generation tip collection (SG-TC) mode SECM measurements performed under steady-state conditions and at different applied substrate potentials, it is possible to extract kinetic information relevant to electrocatalyst substrates such as metalloporphyrin-modified gold and glassy-carbon electrodes. Such an approach allows for the isolation of the unique contribution of the electrocatalyst to the oxygen reduction reaction and peroxide formation.
Mezour
Mohamed A
MA
Laboratory for Electrochemical Reactive Imaging and Detection for Biological Systems, Department of Chemistry, NanoQAM Research Centre, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-ville, Montreal, QC, Canada H3C 3P8.
Cornut
Renaud
R
Hussien
Emad Mohamed
EM
Morin
Mario
M
Mauzeroll
Janine
J
D004563:Electrochemistry; D004566:Electrodes; D006046:Gold; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D036103:Nanotechnology / Q000379:methods*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*
D011166:Porphyrins; D006046:Gold; D006861:Hydrogen Peroxide; D010100:Oxygen