title: Role of a distal pocket in the catalytic O2 reduction by cytochrome c oxidase models immobilized on interdigitated array electrodes.
abstract: Five iron porphyrins with different superstructures were immobilized on self-assembled-monolayer (SAM)-coated interdigitated-array (IDAs) gold-platinum electrodes. The selectivity of the catalysts i.e., limited formation of partially reduced oxygen species (PROS) in the electrocatalytic reduction of dioxygen, is a function of 2 rates: (i) the rate of electron transfer from the electrode to the catalyst, which is controlled by the length, and conjugation of the linker from the catalyst to the electrode and (ii) the rate of bound oxygen (superoxide) hydrolysis, which correlates with the presence of a water cluster in the gas-binding pocket influencing the rate of oxygen binding; these factors are controlled by the nature of the porphyrin superstructure. The structurally biomimetic Tris-imidazole model is the most selective.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, CA 94305, USA. jpc@stanford.edu
authors.forename: James P
authors.initials: JP
authors.lastname: Collman
authors.forename: Richard A
authors.initials: RA
authors.lastname: Decréau
authors.forename: Hengwei
authors.initials: H
authors.lastname: Lin
authors.forename: Ali
authors.initials: A
authors.lastname: Hosseini
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Abhishek
authors.initials: A
authors.lastname: Dey
authors.forename: Todd A
authors.initials: TA
authors.lastname: Eberspacher
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D002384:Catalysis; D004566:Electrodes; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006868:Hydrolysis; D007093:Imidazoles / Q000737:chemistry; D046228:Microarray Analysis; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry; D013481:Superoxides / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D007093:Imidazoles; D011166:Porphyrins; D013481:Superoxides; D010984:Platinum; D006046:Gold; C029899:imidazole; D003576:Electron Transport Complex IV; D010100:Oxygen