TY  - JOUR
A1  - Neumann, Bettina
A1  - Kielb, Patrycja
A1  - Rustam, Lina
A1  - Fischer, Anna
A1  - Weidinger, Inez M.
A1  - Wollenberger, Ulla
T1  - Bioelectrocatalytic Reduction of Hydrogen Peroxide by Microperoxidase-11 Immobilized on Mesoporous Antimony-Doped Tin Oxide
JF  - ChemElectrChem
N2  - The heme-undecapeptide microperoxidase-11 (MP-11) was immobilized on mesoporous antimony-doped tin oxide (ATO) thin-film electrodes modified with the positively charged binding promotor polydiallyldimethylammonium chloride. Surface concentrations of MP-11 of 1.5 nmol cm(-2) were sufficiently high to enable spectroelectrochemical analyses. UV/Vis spectroscopy and resonance Raman spectroscopy revealed that immobilized MP-11 adopts a six-coordinated low-spin conformation, as in solution in the presence of a polycation. Cathodic reduction of hydrogen peroxide at potentials close to +500mV versus Ag/AgCl indicates that the reaction proceeds via a Compound I-type like intermediate, analogous to natural peroxidases, and confirms mesoporous ATO as a suitable host material for adsorbing the heme-peptide in its native state. A hydrogen peroxide sensor is proposed by using the bioelectrocatalytic properties of the MP-11-modified ATO.
KW  - electrochemistry
KW  - enzyme catalysis
KW  - mesoporous materials
KW  - microperoxidase
KW  - spectroelectrochemistry
Y1  - 2017
U6  - https://doi.org/10.1002/celc.201600776
SN  - 2196-0216
VL  - 4
IS  - 4
SP  - 913
EP  - 919
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Brietzke, Thomas Martin
A1  - Dietz, Thomas
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Bois, Juliana
A1  - Kelm, Harald
A1  - Reh, Manuel
A1  - Schmitz, Markus
A1  - Koerzdoerfer, Thomas
A1  - Leimkühler, Silke
A1  - Wollenberger, Ulla
A1  - Krueger, Hans-Joerg
A1  - Holdt, Hans-Jürgen
T1  - The 1,6,7,12-Tetraazaperylene Bridging Ligand as an Electron Reservoir and Its Disulfonato Derivative as Redox Mediator in an Enzyme-Electrode Process
JF  - Chemistry - a European journal
N2  - The homodinuclear ruthenium(II) complex [{Ru(l-N4Me2)}(2)(-tape)](PF6)(4) {[1](PF6)(4)} (l-N4Me2=N,N-dimethyl-2,11-diaza[3.3](2,6)-pyridinophane, tape=1,6,7,12-tetraazaperylene) can store one or two electrons in the energetically low-lying * orbital of the bridging ligand tape. The corresponding singly and doubly reduced complexes [{Ru(l-N4Me2)}(2)(-tape(.-))](PF6)(3) {[2](PF6)(3)} and [{Ru(l-N4Me2)}(2)(-tape(2-))](PF6)(2) {[3](PF6)(2)}, respectively, were electrochemically generated, successfully isolated and fully characterized by single-crystal X-ray crystallography, spectroscopic methods and magnetic susceptibility measurements. The singly reduced complex [2](PF6)(3) contains the -radical tape(.-) and the doubly reduced [3](PF6)(2) the diamagnetic dianion tape(2-) as bridging ligand, respectively. Nucleophilic aromatic substitution at the bridging tape in [1](4+) by two sulfite units gave the complex [{Ru(l-N4Me2)}(2){-tape-(SO3)(2)}](2+) ([4](2+)). Complex dication [4](2+) was exploited as a redox mediator between an anaerobic homogenous reaction solution of an enzyme system (sulfite/sulfite oxidase) and the electrode via participation of the low-energy *-orbital of the disulfonato-substituted bridging ligand tape-(SO3)(2)(2-) (E-red1=-0.1V versus Ag/AgCl/1m KCl in water).
KW  - electrochemistry
KW  - enzyme catalysis
KW  - N-ligands
KW  - redox-active ligands
KW  - ruthenium
Y1  - 2017
U6  - https://doi.org/10.1002/chem.201703639
SN  - 0947-6539
SN  - 1521-3765
VL  - 23
SP  - 15583
EP  - 15587
PB  - Wiley-VCH
CY  - Weinheim
ER  -