TY  - JOUR
A1  - Altintas, Zeynep
A1  - Takiden, Aref
A1  - Utesch, Tillmann
A1  - Mroginski, Maria A.
A1  - Schmid, Bianca
A1  - Scheller, Frieder W.
A1  - Süssmuth, Roderich D.
T1  - Integrated approaches toward high-affinity artificial protein binders obtained via computationally simulated epitopes for protein recognition
JF  - Advanced functional materials
N2  - Widely used diagnostic tools make use of antibodies recognizing targeted molecules, but additional techniques are required in order to alleviate the disadvantages of antibodies. Herein, molecular dynamic calculations are performed for the design of high affinity artificial protein binding surfaces for the recognition of neuron specific enolase (NSE), a known cancer biomarker. Computational simulations are employed to identify particularly stabile secondary structure elements. These epitopes are used for the subsequent molecular imprinting, where surface imprinting approach is applied. The molecular imprints generated with the calculated epitopes of greater stability (Cys-Ep1) show better binding properties than those of lower stability (Cys-Ep5). The average binding strength of imprints created with stabile epitopes is found to be around twofold and fourfold higher for the NSE derived peptide and NSE protein, respectively. The recognition of NSE is investigated in a wide concentration range, where high sensitivity (limit of detection (LOD) = 0.5 ng mL(-1)) and affinity (dissociation constant (K-d) = 5.3 x 10(-11)m) are achieved using Cys-Ep1 imprints reflecting the stable structure of the template molecules. This integrated approach employing stability calculations for the identification of stabile epitopes is expected to have a major impact on the future development of high affinity protein capturing binders.
KW  - artificial protein binders
KW  - cancer markers
KW  - computationally simulated epitopes
KW  - molecular imprinting
KW  - protein recognition
Y1  - 2019
U6  - https://doi.org/10.1002/adfm.201807332
SN  - 1616-301X
SN  - 1616-3028
VL  - 29
IS  - 15
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Caserta, Giorgio
A1  - Zhang, Xiaorong
A1  - Yarman, Aysu
A1  - Supala, Eszter
A1  - Wollenberger, Ulla
A1  - Gyurcsányi, Róbert  E.
A1  - Zebger, Ingo
A1  - Scheller, Frieder W.
T1  - Insights in electrosynthesis, target binding, and stability of peptide-imprinted polymer nanofilms
JF  - Electrochimica acta : the journal of the International Society of Electrochemistry (ISE)
N2  - Molecularly imprinted polymer (MIP) nanofilms have been successfully implemented for the recognition of different target molecules: however, the underlying mechanistic details remained vague. 
This paper provides new insights in the preparation and binding mechanism of electrosynthesized peptide-imprinted polymer nanofilms for selective recognition of the terminal pentapeptides of the beta-chains of human adult hemoglobin, HbA, and its glycated form HbA1c. 
To differentiate between peptides differing solely in a glucose adduct MIP nanofilms were prepared by a two-step hierarchical electrosynthesis that involves first the chemisorption of a cysteinyl derivative of the pentapeptide followed by electropolymerization of scopoletin. 
This approach was compared with a random single-step electrosynthesis using scopo-letin/pentapeptide mixtures. Electrochemical monitoring of the peptide binding to the MIP nanofilms by means of redox probe gating revealed a superior affinity of the hierarchical approach with a Kd value of 64.6 nM towards the related target. 
Changes in the electrosynthesized non-imprinted polymer and MIP nanofilms during chemical, electrochemical template removal and rebinding were substantiated in situ by monitoring the characteristic bands of both target peptides and polymer with surface enhanced infrared absorption spectroscopy. 
This rational approach led to MIPs with excellent selectivity and provided key mechanistic insights with respect to electrosynthesis, rebinding and stability of the formed MIPs.
KW  - SEIRA spectroelectrochemistry
KW  - peptide imprinting
KW  - electrosynthesis
KW  - MIP
KW  - glycated peptide
Y1  - 2021
U6  - https://doi.org/10.1016/j.electacta.2021.138236
SN  - 0013-4686
SN  - 1873-3859
VL  - 381
PB  - Elsevier
CY  - New York, NY [u.a.]
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  - 
TY  - JOUR
A1  - Buttermeyer, R.
A1  - Philipp, A. W.
A1  - Mall, J. W.
A1  - Ge, Bixia
A1  - Scheller, Frieder W.
A1  - Lisdat, Fred
T1  - In vivo measurement of oxygen derived free radicals during reperfusion injury
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Bauer, Christian G.
A1  - Makower, Alexander
A1  - Wollenberger, Ursula
A1  - Warsinke, Axel
A1  - Bier, Frank Fabian
T1  - Immunoassays using enzymatic amplification electrodes
Y1  - 2002
SN  - 0-7484-0791-X
ER  - 
TY  - JOUR
A1  - Beissenhirtz, Moritz Karl
A1  - Scheller, Frieder W.
A1  - Lisdat, Fred
T1  - Immobilized cytochrome c sensor in organic / aqueous media for the characterization of hydrophilic and hydrophobic antioxidants
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Lettau, Kristian
A1  - Gajovic-Eichelmann, N.
A1  - Kwak, Young-Keun
A1  - Scheller, Frieder W.
A1  - Warsinke, Axel
T1  - Hydroxylasen und katalytische Polymere für Biochips
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Xie, B.
A1  - Tang, X.
A1  - Wollenberger, Ursula
A1  - Johansson, G.
A1  - Gorton, Lo
A1  - Scheller, Frieder W.
A1  - Danielsson, B.
T1  - Hybrid biosensor for simultaneous electrochemical and thermal detection
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Bier, Frank Fabian
A1  - Ehrentreich-Förster, Eva
A1  - Bauer, Christian G.
A1  - Scheller, Frieder W.
T1  - High sensitive competitive immunodetection of 2,4-dichlorophenoxyacetic acid using enzymatic amplification with electrochemical detection
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Yarman, Aysu
A1  - Bachmann, Till
A1  - Hirsch, Thomas
A1  - Kubick, Stefan
A1  - Renneberg, Reinhard
A1  - Schumacher, Soeren
A1  - Wollenberger, Ursula
A1  - Teller, Carsten
A1  - Bier, Frank Fabian
ED  - Gu, MB
ED  - Kim, HS
T1  - Future of biosensors: a personal view
JF  - Advances in biochemical engineering, biotechnology
JF  - Advances in Biochemical Engineering-Biotechnology
N2  - Biosensors representing the technological counterpart of living senses have found routine application in amperometric enzyme electrodes for decentralized blood glucose measurement, interaction analysis by surface plasmon resonance in drug development, and to some extent DNA chips for expression analysis and enzyme polymorphisms. These technologies have already reached a highly advanced level and need minor improvement at most. The dream of the "100-dollar' personal genome may come true in the next few years provided that the technological hurdles of nanopore technology or of polymerase-based single molecule sequencing can be overcome. Tailor-made recognition elements for biosensors including membrane-bound enzymes and receptors will be prepared by cell-free protein synthesis. As alternatives for biological recognition elements, molecularly imprinted polymers (MIPs) have been created. They have the potential to substitute antibodies in biosensors and biochips for the measurement of low-molecular-weight substances, proteins, viruses, and living cells. They are more stable than proteins and can be produced in large amounts by chemical synthesis. Integration of nanomaterials, especially of graphene, could lead to new miniaturized biosensors with high sensitivity and ultrafast response. In the future individual therapy will include genetic profiling of isoenzymes and polymorphic forms of drug-metabolizing enzymes especially of the cytochrome P450 family. For defining the pharmacokinetics including the clearance of a given genotype enzyme electrodes will be a useful tool. For decentralized online patient control or the integration into everyday "consumables' such as drinking water, foods, hygienic articles, clothing, or for control of air conditioners in buildings and cars and swimming pools, a new generation of "autonomous' biosensors will emerge.
KW  - Biosensors
KW  - Molecularly imprinted polymers
KW  - Personalized medicine
Y1  - 2014
SN  - 978-3-642-54143-8; 978-3-642-54142-1
U6  - https://doi.org/10.1007/10_2013_251
SN  - 0724-6145
VL  - 140
SP  - 1
EP  - 28
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Jin, Wen
A1  - Bernhardt, Rita
A1  - Lehmann, Claudia
A1  - Stöcklein, Walter F. M.
A1  - Brigelius-Flohé, Regina
A1  - Scheller, Frieder W.
T1  - Funktionalisierung von Elektroden für den direkten heterogenen Elektrotransfer
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Tadjoung Waffo, Armel Franklin
A1  - Yesildag, Cigdem
A1  - Caserta, Giorgio
A1  - Katz, Sagie
A1  - Zebger, Ingo
A1  - Lensen, Marga C.
A1  - Wollenberger, Ulla
A1  - Scheller, Frieder W.
A1  - Altintas, Zeynep
T1  - Fully electrochemical MIP sensor for artemisinin
JF  - Sensors and actuators : B, Chemical
N2  - This study aims to develop a rapid, sensitive and cost-effective biomimetic electrochemical sensor for artemisinin determination in plant extracts and for pharmacokinetic studies. A novel molecularly imprinted polymer (MIP)based electrochemical sensor was developed by electropolymerization of o-phenylenediamine (o-PD) in the presence of artemisinin on gold wire surface for sensitive detection of artemisinin. The experimental parameters, including selection of functional monomer, polymerization conditions, template extraction after polymerization, influence of pH and buffer were all optimized. Every step of imprinted film synthesis were evaluated by employing voltammetry techniques, surface-enhanced infrared absorption spectroscopy (SEIRAS) and atomic force microscopy (AFM). The specificity was further evaluated by investigating non-specific artemisinin binding on non-imprinted polymer (NIP) surfaces and an imprinting factor of 6.8 was achieved. The artemisinin imprinted polymers using o-PD as functional monomer have provided highly stable and effective binding cavities for artemisinin. Cross-reactivity studies with drug molecules showed that the MIPs are highly specific for artemisinin. The influence of matrix effect was further investigated both in artificial plant matrix and diluted human serum. The results revealed a high affinity of artemisinin-MIP with dissociation constant of 7.3 x 10(-9) M and with a detection limit of 0.01 mu M and 0.02 mu M in buffer and plant matrix, respectively.
KW  - Electro-synthesized molecularly imprinted polymer
KW  - o-Phenylenediamine
KW  - Artemisinin
KW  - Antimalarial drug detection
KW  - Electrochemical sensor
Y1  - 2018
U6  - https://doi.org/10.1016/j.snb.2018.08.018
SN  - 0925-4005
VL  - 275
SP  - 163
EP  - 173
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Wagener, C.
T1  - From gene to life
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Baeumner, Antje J.
A1  - Gauglitz, Guenter
A1  - Scheller, Frieder W.
T1  - Focus on bioanalysis
N2  - Editoria
Y1  - 2010
UR  - http://www.springerlink.com/content/100417
U6  - https://doi.org/10.1007/s00216-010-4203-9
SN  - 1618-2642
ER  - 
TY  - JOUR
A1  - Kleinjung, Frank
A1  - Beier, Frank F.
A1  - Warsinke, Axel
A1  - Scheller, Frieder W.
T1  - Fibre-optic genosensor for specific determination of femtomolar DNA oligomers
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Liu, Songqin
A1  - Wollenberger, Ursula
A1  - Katterle, Martin
A1  - Scheller, Frieder W.
T1  - Ferroceneboronic acid-based amperometric biosensor for glycated hemoglobin
N2  - An amperometric biosensor for the determination of glycated hemoglobin in human whole blood is proposed. The principle is based on the electrochemical measurement of ferroceneboronic acid (FcBA) that has been specifically bound to the glycated N-terminus. Hemoglobin is immobilized on a zirconium dioxide nanoparticle modified pyrolytic graphite electrode (PGE) in the presence of didodecyldimethylammonium bromide (DDAB). The incubation of this sensor in FcBA solution leads to the formation of an FcBA-modified surface due to the affinity interaction between boronate and the glycated sites of the hemoglobin. The binding of FcBA results in well-defined redox peaks with an E-0' of 0.299 V versus Ag/AgCl (1 M KCl). The square wave voltammetric response of the bound FcBA reflects the amount of glycated hemoglobin at the surface. This signal increases linearily with the degree of glycated hemoglobin from 6.8 to 14.0% of total immobilized hemoglobin. The scheme was applied to the determination of the fraction of glycated hemoglobin in whole blood samples.
Y1  - 2006
UR  - http://www.sciencedirect.com/science/journal/09254005
U6  - https://doi.org/10.1016/j.snb.2005.07.011
SN  - 0925-4005
ER  - 
TY  - JOUR
A1  - Halamek, Jan
A1  - Teller, Carsten
A1  - Makower, Alexander
A1  - Fournier, Didier
A1  - Scheller, Frieder W.
T1  - EQCN-based cholinesterase biosensors
N2  - The binding of acetylcholinesterase (AChE) to a propidium-modified piezoelectric quartz crystal and its surface enzymatic activity have been investigated. Propidium binds to a site remote to the active center of AChE - the peripheral anionic site (PAS) - which is located on the rim of the gorge to the active site. The gold electrodes of the quartz crystal were first modified with 11-mercaptoundecanoic acid to which propidium was coupled. AChE binding was monitored by a quartz crystal nanobalance (QCN), followed by amperometric activity evaluation of the AChE loaded on the sensor. Interestingly, the binding is strong but does not inhibit AChE. However, an excess of propidium in solution inhibits the immobilized enzyme. The surface enzymatic activities observed depend on the amount of enzyme and differ according to the type and species, i.e. number of enzyme subunits (Electrophorus electricus tetrameric, Drosophila melanogaster mono- and dimeric form - DmAChE). The operational stability and regeneration, effect of propidium in solution and detection limit for substrate for various AChEs were investigated amperometrically.
Y1  - 2006
UR  - http://www.sciencedirect.com/science/journal/00134686
U6  - https://doi.org/10.1016/j.electacta.2006.03.047
SN  - 0013-4686
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Makower, Alexander
A1  - Bier, Frank Fabian
A1  - Wollenberger, Ursula
A1  - Ghindilis, A. L.
A1  - Eremenko, A. V.
A1  - Pfeiffer, Dorothea
T1  - Enzymsensoren zur Bestimmung subnanomolarer Konzentrationen
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Kirstein, Dieter
A1  - Schubert, Florian
A1  - Pfeiffer, Dorothea
A1  - McNeil, C. J.
T1  - Enzymes in electrochemical biosensors
Y1  - 1993
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Scheller, Frieder W.
T1  - Enzymes and antibodies in organic media : analytical applications
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Kaisheva, A.
A1  - Iliev, I.
A1  - Kazareva, R.
A1  - Christov, S.
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Enzyme/gas diffusion electrodes for determination of phenol
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Makower, Alexander
A1  - Ghindilis, A. L.
A1  - Bier, Frank Fabian
A1  - Ehrentreich-Förster, Eva
A1  - Wollenberger, Ursula
A1  - Bauer, Christian G.
A1  - Micheel, Burkhard
A1  - Pfeiffer, Dorothea
A1  - Szeponik, Jan
A1  - Michael, N.
A1  - Kaden, H.
T1  - Enzyme sensors for subnanomolar concentrations
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Makower, Alexander
A1  - Bier, Frank Fabian
A1  - Scheller, Frieder W.
T1  - Enzyme sensors and enzyme amplifification systems
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Behrsing, Olaf
A1  - Scharte, Gudrun
A1  - Micheel, Burkhard
A1  - Benkert, Alexander
A1  - Schössler, W.
A1  - Warsinke, Axel
A1  - Scheller, Frieder W.
T1  - Enzyme kinetic assays with surface plasmon resonance (BIAcore) based on competition between enzyme and creatinine antibody
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Wollenberger, Ursula
T1  - Enzyme Electrodes
Y1  - 2003
SN  - 3-527-30401-0
ER  - 
TY  - JOUR
A1  - Yarman, Aysu
A1  - Badalyan, Artavazd
A1  - Gajovic-Eichelmann, Nenad
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Enzyme electrode for aromatic compounds exploiting the catalytic activities of microperoxidase-11
JF  - Biosensors and bioelectronics : the principal international journal devoted to research, design development and application of biosensors and bioelectronics
N2  - Microperoxidase-11 (MR-11) which has been immobilised in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode catalyzes the conversion of aromatic substances. This peroxide-dependent catalysis of microperoxidase has been applied in an enzyme electrode for the first time to indicate aromatic compounds such as aniline. 4-fluoroaniline, catechol and p-aminophenol. The electrode signal is generated by the cathodic reduction of the quinone or quinoneimine which is formed in the presence of both MP-II and peroxide from the substrate. The same sensor principle will be extended to aromatic drugs.
KW  - Microperoxidase-11
KW  - Nanoparticles
KW  - p-Aminophenol
KW  - Aniline
KW  - Catechol
KW  - 4-Fluoroaniline
KW  - Biosensors
Y1  - 2011
U6  - https://doi.org/10.1016/j.bios.2011.09.004
SN  - 0956-5663
VL  - 30
IS  - 1
SP  - 320
EP  - 323
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Pfeiffer, Dorothea
A1  - Lisdat, Fred
A1  - Bauer, Christian G.
A1  - Gajovic, Nenad
T1  - Enzyme biosensors based on oxygen detection
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Neumann, B.
A1  - Riedel, K.
A1  - Scheller, Frieder W.
T1  - Enzyme and microbial sensors for phosphate, phenols, pesticides and peroxides
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Neumann, B.
A1  - Scheller, Frieder W.
T1  - Enzyme and microbial sensors for environmental Monitoring
Y1  - 1993
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Enzyme activation for activator and enzyme activity measurement
Y1  - 1993
ER  - 
TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Pfeiffer, Dorothea
A1  - Schubert, Florian
A1  - Wollenberger, Ursula
T1  - Enzyme - based electrodes
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Lisdat, Fred
A1  - Scheller, Frieder W.
T1  - Enzymatic substrade recycling electrodes
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Schubert, Florian
A1  - Pfeiffer, Dorothea
A1  - Scheller, Frieder W.
T1  - Enhancing biosensor performance using multienzyme systems
Y1  - 1993
ER  - 
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  - Beissenhirtz, Moritz Karl
A1  - Scheller, Frieder W.
A1  - Viezzoli, Maria Silvia
A1  - Lisdat, Fred
T1  - Engineered superoxide dismutase monomers for superoxide biosensor applications
N2  - Because of its high reaction rate and specificity, the enzyme superoxide dismutase (SOD) offers great potential for the sensitive quantification of superoxide radicals in electrochemical biosensors. In this work, monomeric mutants of human Cu,Zn-SOD were engineered to contain one or two additional cysteine residues, which could be used to bind the protein to gold surfaces, thus making the use of promotor molecules unnecessary. Six mutants were successfully designed, expressed, and purified. All mutants bound directly to unmodified gold surfaces via the sulfur of the cysteine residues and showed a quasireversible, direct electron transfer to the electrode. Thermodynamic and kinetic parameters of the electron transfer were characterized and showed only slight variations between the individual mutants. For one of the mutants, the interaction with the superoxide radical was studied in more detail. For both partial reactions of the dismutation, an interaction between protein and radical could be shown. In an amperometric biosensorial approach, the SOD-mutant electrode was successfully applied for the detection of superoxide radicals. In the oxidation region, the electrode surpassed the sensitivity of the commonly used cytochrome c electrodes by similar to 1 order of magnitude while not being limited by interferences, but the electrode did not fully reach the sensitivity of dimeric Cu,Zn-SOD immobilized on MPA-modified gold
Y1  - 2006
UR  - http://pubs.acs.org/journal/ancham
U6  - https://doi.org/10.1021/Ac051465g
SN  - 0003-2700
ER  - 
TY  - JOUR
A1  - Kirstein, Dieter
A1  - Kirstein, Lincoln
A1  - Scheller, Frieder W.
A1  - Dieckmann, St.
A1  - Ronnenberg, J.
A1  - Beckmann, Dieter
A1  - Weckenbrock, E.
T1  - Elektroenzymatische Reduktion von Nitrat
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Bistolas, Nikitas
A1  - Jung, Christiane
A1  - Shumyantseva, V. V.
A1  - Ruzgas, T.
A1  - Scheller, Frieder W.
T1  - Elektroden-Design für elektronische Wechselwirkung mit Monooxygenasen
Y1  - 2004
SN  - 3-8047-2132-x
ER  - 
TY  - JOUR
A1  - Stojanovic, Zorica
A1  - Erdossy, Julia
A1  - Keltai, Katalin
A1  - Scheller, Frieder W.
A1  - Gyurcsanyi, Robert E.
T1  - Electrosynthesized molecularly imprinted polyscopoletin nanofilms for human serum albumin detection
JF  - Analytica chimica acta : an international journal devoted to all branches of analytical chemistry
N2  - Molecularly imprinted polymers (MIPs) rendered selective solely by the imprinting with protein templates lacking of distinctive properties to facilitate strong target-MIP interaction are likely to exhibit medium to low template binding affinities. While this prohibits the use of such MIPs for applications requiring the assessment of very low template concentrations, their implementation for the quantification of high-abundance proteins seems to have a clear niche in the analytical practice. We investigated this opportunity by developing a polyscopoletin-based MIP nanofilm for the electrochemical determination of elevated human serum albumin (HSA) in urine. As reference for a low abundance protein ferritin-MIPs were also prepared by the same procedure. Under optimal conditions, the imprinted sensors gave a linear response to HSA in the concentration range of 20-100 mg/dm(3), and to ferritin in the range of 120-360 mg/dm(3). While as expected the obtained limit of detection was not sufficient to determine endogenous ferritin in plasma, the HSA-sensor was successfully employed to analyse urine samples of patients with albuminuria. The results suggest that MIP-based sensors may be applicable for quantifying high abundance proteins in a clinical setting. (c) 2017 Elsevier B.V. All rights reserved.
KW  - Human serum albumin
KW  - Ferritin
KW  - Molecularly imprinted polymer
KW  - Scopoletin
KW  - Urine
Y1  - 2017
U6  - https://doi.org/10.1016/j.aca.2017.04.043
SN  - 0003-2670
SN  - 1873-4324
VL  - 977
SP  - 1
EP  - 9
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Zhang, Xiaorong
A1  - Yarman, Aysu
A1  - Erdossy, Julia
A1  - Katz, Sagie
A1  - Zebger, Ingo
A1  - Jetzschmann, Katharina J.
A1  - Altintas, Zeynep
A1  - Wollenberger, Ulla
A1  - Gyurcsanyi, Robert E.
A1  - Scheller, Frieder W.
T1  - Electrosynthesized MIPs for transferrin
BT  - Plastibodies or nano-filters?
JF  - Biosensors and bioelectronics : the principal international journal devoted to research, design development and application of biosensors and bioelectronics
N2  - Molecularly imprinted polymer (MP) nanofilrns for transferrin (Trf) have been synthesized on gold surfaces by electro-polymerizing the functional monomer scopoletin in the presence of the protein target or around pre-adsorbed Trf. As determined by atomic force microscopy (AFM) the film thickness was comparable with the molecular dimension of the target. The target (re)binding properties of the electro-synthesized MIP films was evaluated by cyclic voltammetry (CV) and square wave voltammetry (SWV) through the target-binding induced permeability changes of the MIP nanofilms to the ferricyanide redox marker, as well as by surface plasmon resonance (SPR) and surface enhanced infrared absorption spectroscopy (SEIRAS) of the immobilized protein molecules. For Trf a linear concentration dependence in the lower micromolar range and an imprinting factor of similar to 5 was obtained by SWV and SPR. Furthermore, non-target proteins including the iron-free apo-Trf were discriminated by pronounced size and shape specificity. Whilst it is generally assumed that the rebinding of the target or of cross-reacting proteins exclusively takes place at the polymer here we considered also the interaction of the protein molecules with the underlying gold transducers. We demonstrate by SWV that adsorption of proteins suppresses the signal of the redox marker even at the bare gold surface and by SEIRAS that the treatment of the MIP with proteinase K or NaOH only partially removes the target protein. Therefore, we conclude that when interpreting binding of proteins to directly MIP-covered gold electrodes the interactions between the protein and the gold surface should also be considered.
KW  - Molecularly imprinted polymer
KW  - Scopoletin
KW  - Transferrin
KW  - Protein adsorption
KW  - Redox marker
Y1  - 2018
U6  - https://doi.org/10.1016/j.bios.2018.01.011
SN  - 0956-5663
SN  - 1873-4235
VL  - 105
SP  - 29
EP  - 35
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Lei, Chenghong
A1  - Wollenberger, Ursula
A1  - Bistolas, Nikitas
A1  - Guiseppi-Eli, A.
A1  - Scheller, Frieder W.
T1  - Electron transfer of hemoglobin at electrodes modified with colloidal clay nanoparticles
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Ge, Bixia
A1  - Scheller, Frieder W.
A1  - Lisdat, Fred
T1  - Electrochemistry of immobilized CuZnSOD and FeSOD and their interaction with superoxide radicals
N2  - Copper, zinc superoxide dismutase (CuZnSOD) from bovine erythrocytes and iron superoxide dismutase from Escherichia coli (FeSOD) were immobilized on 3-mercaptopropionic acid (MPA)-modified gold electrodes, respectively. The characterization of the SOD electrodes showed a quasi-reversible, electrochemical redox behavior with a formal potential of 47 ñ 4 mV and -154 ñ 5 mV (vs. Ag/AgCl, 1 M KCl) for surface adsorbed CuZnSOD and FeSOD, respectively. The heterogeneous electron transfer rate constants were determined to be about 65 and 35/s, respectively. Covalent fixation of both SODs was also feasible with only slight changes in the formal potential. The interaction of superoxide radicals (O2-) with the SOD electrode was investigated. No catalytic current could be observed. However, due to the fast cyclic reaction of SOD with superoxide, the communication of the protein with the electrode was strongly influenced. The amperometric detection of superoxide radicals is discussed.
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Katterle, Martin
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Electrochemistry of hemoglobin at modified silver electrodes is not a redox-process of iron protoporhyrin IX
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Ju, Huangxian
A1  - Liu, Songqin
A1  - Ge, Bixia
A1  - Lisdat, Fred
A1  - Scheller, Frieder W.
T1  - Electrochemistry of cytochrome c immobilized on colloidal gold modified carbon paste electrodes and its electrocatalytic activity
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Pfeiffer, Dorothea
A1  - Schubert, Frank
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Electrochemical sensors : enzyme electrodes and field effect transistors
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Welzel, H.-P.
A1  - Kossmehl, G.
A1  - Engelmann, G.
A1  - Neumann, B.
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Electrochemical polymerization of functionalized thiohene derivatives for immobilization of proteins
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Kulys, J.
A1  - Krikstopaitis, K.
A1  - Scheller, Frieder W.
A1  - Wollenberger, Ursula
T1  - Electrochemical parameters of phenoxazine derivatives in solution and at monolayer-modified gold electrodes
N2  - Electrochemical properties of beta-(10-phenoxazinyl) propylamine (APPX) and beta-(10-phenoxazinyl) propionic acid (PPX) have been studied in solution, and in immobilized state on gold electrodes modified with monolayers of cystamine and mercaptoundecanoic acid. A reversible diffusion-controlled process of APPX and PPX was observed at a bare gold electrode. The electrochemical conversion of both compounds at modified gold electrodes was a quasireversible diffusion-controlled process. The redox potential of immobilized APPX (443 mV) was similar to the potential in solution, while the value of the immobilized PPX was 131 mV higher than in solution. The immobilized mediators were electrocatalytically active in the fungal peroxidase-catalyzed hydrogen peroxide reduction
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Ozcelikay, Goksu
A1  - Kurbanoglu, Sevinc
A1  - Zhang, Xiaorong
A1  - Söz, Çağla Kosak
A1  - Wollenberger, Ulla
A1  - Ozkan, Sibel A.
A1  - Yarman, Aysu
A1  - Scheller, Frieder W.
T1  - Electrochemical MIP Sensor for Butyrylcholinesterase
JF  - Polymers
N2  - Molecularly imprinted polymers (MIPs) mimic the binding sites of antibodies by substituting the amino acid-scaffold of proteins by synthetic polymers. In this work, the first MIP for the recognition of the diagnostically relevant enzyme butyrylcholinesterase (BuChE) is presented. The MIP was prepared using electropolymerization of the functional monomer o-phenylenediamine and was deposited as a thin film on a glassy carbon electrode by oxidative potentiodynamic polymerization. Rebinding and removal of the template were detected by cyclic voltammetry using ferricyanide as a redox marker. Furthermore, the enzymatic activity of BuChE rebound to the MIP was measured via the anodic oxidation of thiocholine, the reaction product of butyrylthiocholine. The response was linear between 50 pM and 2 nM concentrations of BuChE with a detection limit of 14.7 pM. In addition to the high sensitivity for BuChE, the sensor responded towards pseudo-irreversible inhibitors in the lower mM range.
KW  - molecularly imprinted polymers
KW  - biomimetic sensors
KW  - butyrylcholinesterase
KW  - o-phenylenediamine
KW  - rivastigmine
Y1  - 2019
U6  - https://doi.org/10.3390/polym11121970
SN  - 2073-4360
VL  - 11
IS  - 12
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Jin, Wen
A1  - Wollenberger, Ursula
A1  - Kärgel, E.
A1  - Schunck, W.-H.
A1  - Scheller, Frieder W.
T1  - Electrochemical investigation of the intermolecular electron transfer between cytochrome c and NADPH-cytochrome P450-reductase
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Fridman, Vadim
A1  - Wollenberger, Ursula
A1  - Bogdanovskaya, V. A.
A1  - Lisdat, Fred
A1  - Ruzgas, T.
A1  - Lindgren, A.
A1  - Gorton, Lo
A1  - Scheller, Frieder W.
T1  - Electrochemical investigation of cellobiose oxidation by cellobiose dehydrogenase in the presence of cytochrome c as mediator
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Warsinke, Axel
A1  - Benkert, Alexander
A1  - Scheller, Frieder W.
T1  - Electrochemical immunoassays
Y1  - 2000
ER  -