TY  - JOUR
A1  - Neumann, Bettina
A1  - Götz, Robert
A1  - Wrzolek, Pierre
A1  - Scheller, Frieder W.
A1  - Weidinger, Inez M.
A1  - Schwalbe, Matthias
A1  - Wollenberger, Ulla
T1  - Enhancement of the Electrocatalytic Activity of Thienyl-Substituted Iron Porphyrin Electropolymers by a Hangman Effect
JF  - ChemCatChem : heterogeneous & homogeneous & bio- & nano-catalysis ; a journal of ChemPubSoc Europe
N2  - The thiophene-modified iron porphyrin FeT3ThP and the respective iron Hangman porphyrin FeH3ThP, incorporating a carboxylic acid hanging group in the second coordination sphere of the iron center, were electropolymerized on glassy carbon electrodes using 3,4-ethylenedioxythiophene (EDOT) as co-monomer. Scanning electron microscopy images and Resonance Raman spectra demonstrated incorporation of the porphyrin monomers into a fibrous polymer network. Porphyrin/polyEDOT films catalyzed the reduction of molecular oxygen in a four-electron reaction to water with onset potentials as high as +0.14V vs. Ag/AgCl in an aqueous solution of pH7. Further, FeT3ThP/polyEDOT films showed electrocatalytic activity towards reduction of hydrogen peroxide at highly positive potentials, which was significantly enhanced by introduction of the carboxylic acid hanging group in FeH3ThP. The second coordination sphere residue promotes formation of a highly oxidizing reaction intermediate, presumably via advantageous proton supply, as observed for peroxidases and catalases making FeH3ThP/polyEDOT films efficient mimics of heme enzymes.
KW  - activation of oxygen species
KW  - electro-polymerization
KW  - Hangman porphyrin
KW  - heterogeneous catalysis
KW  - immobilization
Y1  - 2018
U6  - https://doi.org/10.1002/cctc.201800934
SN  - 1867-3880
SN  - 1867-3899
VL  - 10
IS  - 19
SP  - 4353
EP  - 4361
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Loew, Noya
A1  - Bogdanoff, Peter
A1  - Herrmann, Iris
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
A1  - Katterle, Martin
T1  - Influence of modifications on the efficiency of pyrolysed CoTMPP as electrode material for horseradish peroxidase and the reduction of hydrogen peroxide
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
N2  - A tailor-made horseradish peroxidase (HRP) bulk composite electrode was developed on the basis of pyrolyzed cobalt tetramethoxyphenylporphyrin (CoTMPP) by modifying pore size and surface area of the porous carbon material through varying amounts of iron oxalate and sulfur prior to pyrolyzation. The materials were used to immobilize horseradish peroxidase (HRP). These electrodes were characterized in terms of their efficiency to reduce hydrogen peroxide. The heterogeneous electron transfer rate constants of different materials were determined with the rotating disk electrode method and a k(S) (401 +/- 61 s(-1)) exceeding previously reported values for native HRP was found.
KW  - cobalt porphyrin
KW  - electron transfer
KW  - horseradish peroxidase
KW  - hydrogen peroxide
KW  - immobilization
Y1  - 2006
U6  - https://doi.org/10.1002/elan.200603664
SN  - 1040-0397
VL  - 18
IS  - 23
SP  - 2324
EP  - 2330
PB  - Wiley-VCH
CY  - Weinheim
ER  -