TY  - JOUR
A1  - Peter, Martin G.
A1  - Wollenberger, Ursula
T1  - Phenol-oxidizing enzymes : mechanisms and applications
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Streffer, Katrin
A1  - Kaatz, Helvi
A1  - Bauer, Christian G.
A1  - Makower, Alexander
A1  - Schulmeister, Thomas
A1  - Scheller, Frieder W.
A1  - Peter, Martin G.
A1  - Wollenberger, Ursula
T1  - Application of a sensitive catechol detector for determination of tyrosinase inhibitors
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Kaatz, Helvi
A1  - Streffer, Katrin
A1  - Wollenberger, Ursula
A1  - Peter, Martin G.
T1  - Inhibition of mushroom tyrosinase by kojic acid octanoates
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Yarman, Aysu
A1  - Nagel, Thomas
A1  - Gajovic-Eichelmann, Nenad
A1  - Fischer, Anna
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Bioelectrocatalysis by Microperoxidase-11 in a Multilayer Architecture of Chitosan Embedded Gold Nanoparticles
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
N2  - We report on the redox behaviour of the microperoxidase-11 (MP-11) which has been electrostatically immobilized in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode. MP-11 contains a covalently bound heme c as the redox active group that exchanges electrons with the electrode via the gold nanoparticles. Electroactive surface concentration of MP-11 at high scan rate is between 350+/-50 pmol cm(-2), which reflects a multilayer process. The formal potential (E degrees') of MP-11 in the gold nanoparticles-chitosan film was estimated to be -(267.7+/-2.9) mV at pH 7.0. The heterogeneous electron transfer rate constant (k(s)) starts at 1.21 s(-1) and levels off at 6.45 s(-1) in the scan rate range from 0.1 to 2.0 V s(-1). Oxidation and reduction of MP-11 by hydrogen peroxide and superoxide, respectively have been coupled to the direct electron transfer of MP-11.
KW  - Microperoxidase
KW  - Direct electron transfer
KW  - Nanoparticles
KW  - Hydrogen peroxide
KW  - Superoxide
KW  - Bioelectrocatalysis
Y1  - 2011
U6  - https://doi.org/10.1002/elan.201000535
SN  - 1040-0397
VL  - 23
IS  - 3
SP  - 611
EP  - 618
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Comminges, Clement
A1  - Frasca, Stefano
A1  - Suetterlin, Martin
A1  - Wischerhoff, Erik
A1  - Laschewsky, André
A1  - Wollenberger, Ursula
T1  - Surface modification with thermoresponsive polymer brushes for a switchable electrochemical sensor
JF  - RSC Advances
N2  - Elaboration of switchable surfaces represents an interesting way for the development of a new generation of electrochemical sensors. In this paper, a method for growing thermoresponsive polymer brushes from a gold surface pre-modified with polyethyleneimine (PEI), subsequent layer-by-layer polyelectrolyte assembly and adsorption of a charged macroinitiator is described. We propose an easy method for monitoring the coil-to-globule phase transition of the polymer brush using an electrochemical quartz crystal microbalance with dissipation (E-QCM-D). The surface of these polymer modified electrodes shows reversible switching from the swollen to the collapsed state with temperature. As demonstrated from E-QCM-D measurements using an original signal processing method, the switch is operating in three reversible steps related to different interfacial viscosities. Moreover, it is shown that the one electron oxidation of ferrocene carboxylic acid is dramatically affected by the change from the swollen to the collapsed state of the polymer brush, showing a spectacular 86% decrease of the charge transfer resistance between the two states.
Y1  - 2014
U6  - https://doi.org/10.1039/c4ra07190e
SN  - 2046-2069
VL  - 4
IS  - 81
SP  - 43092
EP  - 43097
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Zeng, Ting
A1  - Frasca, Stefano
A1  - Rumschöttel, Jens
A1  - Koetz, Joachim
A1  - Leimkühler, Silke
A1  - Wollenberger, Ursula
T1  - Role of Conductive Nanoparticles in the Direct Unmediated Bioelectrocatalysis of Immobilized Sulfite Oxidase
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
KW  - Direct electron transfer
KW  - Protein voltammetry
KW  - Human sulfite oxidase
KW  - Bioelectrocatalysis
KW  - Nanoparticles
Y1  - 2016
U6  - https://doi.org/10.1002/elan.201600246
SN  - 1040-0397
SN  - 1521-4109
VL  - 28
SP  - 2303
EP  - 2310
PB  - Wiley-VCH
CY  - Weinheim
ER  -