title: Scanning electrochemical microscopy. 24. Enzyme ultramicroelectrodes for the measurement of hydrogen peroxide at surfaces.
abstract: Hydrogen peroxide sensing microelectrodes for scanning electrochemical microscopy (SECM) have been developed and used to measure hydrogen peroxide in the diffusion layer during electrochemical reduction of oxygen on gold and carbon electrodes. These microelectrode biosensors were also used to detect immobilized glucose oxidase through the production of hydrogen peroxide during enzymatic oxidation of glucose. Images of hydrogen peroxide concentration profiles near a platinum microdisk during catalytic decomposition of peroxide and in the diffusion layer of a carbon-platinum composite electrode during oxygen reduction are presented. The factors limiting the spatial resolution (tens of micrometers) and potential applications of the technique are discussed.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Austin 78712.
authors.forename: B R
authors.initials: BR
authors.lastname: Horrocks
authors.forename: D
authors.initials: D
authors.lastname: Schmidtke
authors.forename: A
authors.initials: A
authors.lastname: Heller
authors.forename: A J
authors.initials: AJ
authors.lastname: Bard
mesh_terms: D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry; D004058:Diffusion; D004800:Enzymes, Immobilized; D005949:Glucose Oxidase / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000032:analysis*; D008839:Microelectrodes; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D010984:Platinum; D002244:Carbon; D006046:Gold; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase