TY  - JOUR
A1  - Yarman, Aysu
A1  - Kurbanoglu, Sevinc
A1  - Jetzschmann, Katharina J.
A1  - Ozkan, Sibel A.
A1  - Wollenberger, Ulla
A1  - Scheller, Frieder W.
T1  - Electrochemical MIP-Sensors for Drugs
JF  - Current Medicinal Chemistry
N2  - In order to replace bio-macromolecules by stable synthetic materials in separation techniques and bioanalysis biomimetic receptors and catalysts have been developed: Functional monomers are polymerized together with the target analyte and after template removal cavities are formed in the "molecularly imprinted polymer" (MIP) which resemble the active sites of antibodies and enzymes. Starting almost 80 years ago, around 1,100 papers on MIPs were published in 2016. Electropolymerization allows to deposit MIPs directly on voltammetric electrodes or chips for quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). For the readout of MIPs for drugs amperometry, differential pulse voltammetry (DPV) and impedance spectroscopy (EIS) offer higher sensitivity as compared with QCM or SPR. Application of simple electrochemical devices allows both the reproducible preparation of MIP sensors, but also the sensitive signal generation. Electrochemical MIP-sensors for the whole arsenal of drugs, e.g. the most frequently used analgesics, antibiotics and anticancer drugs have been presented in literature and tested under laboratory conditions. These biomimetic sensors typically have measuring ranges covering the lower nano-up to millimolar concentration range and they are stable under extreme pH and in organic solvents like nonaqueous extracts.
KW  - Biomimetic sensors
KW  - molecularly imprinted polymers
KW  - drug sensors
KW  - drug imprinting
KW  - electropolymerization
KW  - electrochemical sensors
Y1  - 2018
U6  - https://doi.org/10.2174/0929867324666171005103712
SN  - 0929-8673
SN  - 1875-533X
VL  - 25
IS  - 33
SP  - 4007
EP  - 4019
PB  - Bentham Science Publishers LTD
CY  - Sharjah
ER  - 
TY  - JOUR
A1  - Yarman, Aysu
A1  - Jetzschmann, Katharina J.
A1  - Neumann, Bettina
A1  - Zhang, Xiaorong
A1  - Wollenberger, Ulla
A1  - Cordin, Aude
A1  - Haupt, Karsten
A1  - Scheller, Frieder W.
T1  - Enzymes as Tools in MIP-Sensors
JF  - Chemosensors
N2  - Molecularly imprinted polymers (MIPs) have the potential to complement antibodies in bioanalysis, are more stable under harsh conditions, and are potentially cheaper to produce. However, the affinity and especially the selectivity of MIPs are in general lower than those of their biological pendants. Enzymes are useful tools for the preparation of MIPs for both low and high-molecular weight targets: As a green alternative to the well-established methods of chemical polymerization, enzyme-initiated polymerization has been introduced and the removal of protein templates by proteases has been successfully applied. Furthermore, MIPs have been coupled with enzymes in order to enhance the analytical performance of biomimetic sensors: Enzymes have been used in MIP-sensors as tracers for the generation and amplification of the measuring signal. In addition, enzymatic pretreatment of an analyte can extend the analyte spectrum and eliminate interferences.
KW  - enzymatic MIP synthesis
KW  - template digestion
KW  - enzyme tracer
KW  - enzymatic analyte conversion
KW  - molecularly imprinted polymers
Y1  - 2017
U6  - https://doi.org/10.3390/chemosensors5020011
SN  - 2227-9040
VL  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Yarman, Aysu
A1  - Gröbe, Glenn
A1  - Neumann, Bettina
A1  - Kinne, Mathias
A1  - Gajovic-Eichelmann, Nenad
A1  - Wollenberger, Ursula
A1  - Hofrichter, Martin
A1  - Ullrich, Rene
A1  - Scheibner, Katrin
A1  - Scheller, Frieder W.
T1  - The aromatic peroxygenase from Marasmius rutola-a new enzyme for biosensor applications
JF  - Analytical & bioanalytical chemistry
N2  - The aromatic peroxygenase (APO; EC 1.11.2.1) from the agraric basidomycete Marasmius rotula (MroAPO) immobilized at the chitosan-capped gold-nanoparticle-modified glassy carbon electrode displayed a pair of redox peaks with a midpoint potential of -278.5 mV vs. AgCl/AgCl (1 M KCl) for the Fe(2+)/Fe(3+) redox couple of the heme-thiolate-containing protein. MroAPO oxidizes aromatic substrates such as aniline, p-aminophenol, hydroquinone, resorcinol, catechol, and paracetamol by means of hydrogen peroxide. The substrate spectrum overlaps with those of cytochrome P450s and plant peroxidases which are relevant in environmental analysis and drug monitoring. In M. rotula peroxygenase-based enzyme electrodes, the signal is generated by the reduction of electrode-active reaction products (e.g., p-benzoquinone and p-quinoneimine) with electro-enzymatic recycling of the analyte. In these enzyme electrodes, the signal reflects the conversion of all substrates thus representing an overall parameter in complex media. The performance of these sensors and their further development are discussed.
KW  - Unspecific peroxygenase
KW  - Cytochrome P450
KW  - Biosensors
KW  - Phenolic substances
Y1  - 2012
U6  - https://doi.org/10.1007/s00216-011-5497-y
SN  - 1618-2642
VL  - 402
IS  - 1
SP  - 405
EP  - 412
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Yarman, Aysu
A1  - Dechtrirat, Decha
A1  - Bosserdt, Maria
A1  - Jetzschmann, Katharina J.
A1  - Gajovic-Eichelmann, Nenad
A1  - Scheller, Frieder W.
T1  - Cytochrome c-derived hybrid systems based on moleculary imprinted polymers
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
N2  - Hybrid architectures which combine a MIP with an immobilized affinity ligand or a biocatalyst sum up the advantages of both components. In this paper, hybrid architectures combining a layer of a molecularly imprinted electropolymer with a mini-enzyme or a self-assembled monolayer will be presented. (i) Microperoxidase-11 (MP-11) catalyzed oxidation of the drug aminopyrine on a product-imprinted sublayer: The peroxide dependent conversion of the analyte aminopyrine takes place in the MP-11 containing layer on top of a product-imprinted electropolymer on the indicator electrode. The hierarchical architecture resulted in the elimination of interfering signals for ascorbic acid and uric acid. An advantage of the new hierarchical structure is the separation of MIP formation by electropolymerization and immobilization of the catalyst. In this way it was for the first time possible to integrate an enzyme with a MIP layer in a sensor configuration. This combination has the potential to be transferred to other enzymes, e.g. P450, opening the way to clinically important analytes. (ii) Epitope-imprinted poly-scopoletin layer for binding of the C-terminal peptide and cytochrome c (Cyt c): The MIP binds both the target peptide and the parent protein almost eight times stronger than the non-imprinted polymer with affinities in the lower micromolar range. Exchange of only one amino acid in the peptide decreases the binding by a factor of five. (iii) MUA-poly-scopoletin MIP for cytochrome c: Cyt c bound to the MIP covered gold electrode exhibits direct electron transfer with a redox potential and rate constant typical for the native protein. The MIP cover layer suppresses the displacement of the target protein by BSA or myoglobin. The combination of protein imprinted polymers with an efficient electron transfer is a new concept for characterizing electroactive proteins such as Cyt c. The competition with other proteins shows that the MIP binds its target Cyt c preferentially and that molecular shape and the charge of protein determine the binding of interfering proteins.
KW  - Molecularly imprinted polymers
KW  - Microperoxidase-11
KW  - Cytochrome c
KW  - Catalytically active MIPs
KW  - Epitope imprinting
KW  - Monoclonal MIPs
Y1  - 2015
U6  - https://doi.org/10.1002/elan.201400592
SN  - 1040-0397
SN  - 1521-4109
VL  - 27
IS  - 3
SP  - 573
EP  - 586
PB  - Wiley-VCH
CY  - Weinheim
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  - 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  - Wu, Yunhua
A1  - Wollenberger, Ursula
A1  - Hofrichter, Martin
A1  - Ullrich, Rene
A1  - Scheibner, Katrin
A1  - Scheller, Frieder W.
T1  - Direct electron transfer of Agrocybe aegerita peroxygenase at electrodes modified with chitosan-capped Au nanoparticles and its bioelectrocatalysis to aniline
JF  - Sensors and actuators : B, Chemical
N2  - Three different sizes of chitosan-capped Au nanoparticles were synthesized and were used to incorporate Agrocybe aegerita peroxygenase (AaeAPO) onto the surface of glassy carbon electrode. The direct electron transfer of AaeAPO was achieved in all films. The highest amount of electroactive enzyme and highest electron transfer rate constant k(s) of AaeAPO were obtained in the film with the smallest size of chitosan-capped Au nanoparticles.
 In anaerobic solutions, quasi-reversible oxidation and reduction are obtained with a formal potential of -0.280V vs. Ag/AgCl 1 M KCl in 100 mM (pH 7.0) PBS at scan rate of 1 V s(-1). Bioelectrocatalytic reduction currents can be obtained with the AaeAPO-modified electrode on addition of hydrogen peroxide. This reaction was suppressed when sodium azide, an inhibitor of AaeAPO, was present. Furthermore, the peroxide-dependent conversion of aniline was characterized and it was found that a polymer product via p-aminophenol is formed. And the AaeAPO biosensor was applied to determine aniline and p-aminophenol.
KW  - Agrocybe aegerita peroxygenase
KW  - Au nanoparticles
KW  - Direct electron transfer
KW  - Aniline biosensor
KW  - Bioelectrocatalysis
Y1  - 2011
U6  - https://doi.org/10.1016/j.snb.2011.09.090
SN  - 0925-4005
VL  - 160
IS  - 1
SP  - 1419
EP  - 1426
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Schubert, Florian
A1  - Pfeiffer, Dorothea
A1  - Scheller, Frieder W.
T1  - Recycling sensors based on kinases : proceedings of Mosbach Symposion on Biochemical Technology
Y1  - 1996
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  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Enzyme activation for activator and enzyme activity measurement
Y1  - 1993
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Neumann, B.
A1  - Scheller, Frieder W.
T1  - Development of a biomimetic alkane sensor f
Y1  - 1998
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  - 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  - Lisdat, Fred
A1  - Scheller, Frieder W.
T1  - Enzymatic substrade recycling electrodes
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Hintsche, R.
A1  - Scheller, Frieder W.
T1  - Biosensors for analytical microsystems
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
A1  - Drungiliene, A.
A1  - Stöcklein, Walter F. M.
A1  - Kulys, J.
A1  - Scheller, Frieder W.
T1  - Direct electrocatalytic determination of dissolved peroxidases
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.
A1  - Schröder, W.
T1  - Reactive groups on polymer covered electrodes, 4. Lactate-oxidase-biosensor based on electrodes modifies by polyphiophene
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  - Warsinke, Axel
A1  - Stancik, L.
A1  - Macholán, L.
A1  - Pfeiffer, Dorothea
A1  - Scheller, Frieder W.
T1  - Biosensors for food analysis : application of biosensors to food requirements
Y1  - 1998
SN  - 0-85404-750-6
ER  - 
TY  - JOUR
A1  - Warsinke, Axel
A1  - Benkert, Alexander
A1  - Scheller, Frieder W.
T1  - Biomolecular modules for creatinine determination
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Warsinke, Axel
A1  - Benkert, Alexander
A1  - Scheller, Frieder W.
T1  - Electrochemical immunoassays
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Vijgenboom, E.
A1  - Vijgenboom, E.
A1  - Teppner, A. W. J. W.
A1  - Makower, Alexander
A1  - Scheller, Frieder W.
A1  - Canters, Gerard W.
A1  - Wollenberger, Ursula
T1  - Determination of phenolic compounds using recombinant tyrosinanse from Streptomyces antibioticus
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Teller, C.
A1  - Halamek, Jan
A1  - Makower, Alexander
A1  - Fournier, Didier
A1  - Schulze, H.
A1  - Scheller, Frieder W.
T1  - A piezoelectric sensor with propidium as a recognition element for cholinesterases
N2  - A piezoelectric biosensor has been developed on the basis of the reversible acetylcholinesterase (AChE) inhibitor propidium. The propidium cation was bound to a 11-mercaptoundecanoic acid monolayer on gold-coated quartz crystals. The immobilization was done via activation of carboxyl groups by 1,3-dicyclohexylcarbodiimide (DCC). Different types of cholinesterases (acetyl- and butyryl-ChE) from different origins were tested for their binding ability towards the immobilized propidium. Binding Studies were performed in a flow system, Furthermore, catalytically active and organophosphate-inhibited enzyme were compared re-aiding their binding capability. The binding constants were derived by using an one to one binding model and a refined model also including rebinding effects. It was shown that organophosphorylation of the active site hardly influences the affinity of AChE towards propidium. Furthermore the propidium-based biosensor provides equal sensitivity as compared with piezolelectric sensors with immobilized paraoxon- an active site ligand of AChE. (c) 2005 Elsevier B.V. All rights reserved
Y1  - 2006
U6  - https://doi.org/10.1016/j.snb.2005.02.053
ER  - 
TY  - JOUR
A1  - Tanne, Johannes
A1  - Jeoung, Jae-Hun
A1  - Peng, Lei
A1  - Yarman, Aysu
A1  - Dietzel, Birgit
A1  - Schulz, Burkhard
A1  - Schad, Daniel
A1  - Dobbek, Holger
A1  - Wollenberger, Ursula
A1  - Bier, Frank Fabian
A1  - Scheller, Frieder W.
T1  - Direct Electron Transfer and Bioelectrocatalysis by a Hexameric, Heme Protein at Nanostructured Electrodes
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
N2  - A nanohybrid consisting of poly(3-aminobenzenesulfonic acid-co-aniline) and multiwalled carbon nanotubes [MWCNT-P(ABS-A)]) on a gold electrode was used to immobilize the hexameric tyrosine-coordinated heme protein (HTHP). The enzyme showed direct electron transfer between the heme group of the protein and the nanostructured surface. Desorption of the noncovalently bound heme from the protein could be excluded by control measurements with adsorbed hemin on aminohexanthiol-modified electrodes. The nanostructuring and the optimised charge characteristics resulted in a higher protein coverage as compared with MUA/MU modified electrodes. The adsorbed enzyme shows catalytic activity for the cathodic H2O2 reduction and oxidation of NADH.
KW  - HTHP
KW  - Nanohybrid
KW  - Poylaniline
KW  - Multiwalled carbon nanotube
Y1  - 2015
U6  - https://doi.org/10.1002/elan.201500231
SN  - 1040-0397
SN  - 1521-4109
VL  - 27
IS  - 10
SP  - 2262
EP  - 2267
PB  - Wiley-VCH
CY  - Weinheim
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  - Szeponik, Jan
A1  - Möller, B.
A1  - Pfeiffer, Dorothea
A1  - Lisdat, Fred
A1  - Wollenberger, Ursula
A1  - Makower, Alexander
A1  - Scheller, Frieder W.
T1  - Ultrasensitive bienzyme sensor for adrenaline
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Stöllner, Daniela
A1  - Stöcklein, Walter F. M.
A1  - Scheller, Frieder W.
A1  - Warsinke, Axel
T1  - Membrane-immobilized haptoglobin as affinity matrix for a hemoglobin-A1c-immunosensor
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Warsinke, Axel
A1  - Scheller, Frieder W.
T1  - Organic solvent modified enzyme-liked immunoassay for the detection of triazine herbicides
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Warsinke, Axel
A1  - Micheel, Burkhard
A1  - Kempter, Gerhard
A1  - Höhne, Wolfgang
A1  - Scheller, Frieder W.
T1  - Diphenylurea hapten sensing with a monoclonal antibody and its Fab fragment : kinetic and thermodynamic investigations
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Warsinke, Axel
A1  - Micheel, Burkhard
A1  - Höhne, Wolfgang
A1  - Woller, Jochen
A1  - Kempter, Gerhard
A1  - Scheller, Frieder W.
T1  - Characterization of a monoclonal antibody and its Fab fragment against diphenylurea hapten with BIA
Y1  - 1998
SN  - 3-8154-3540-4
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Warsinke, Axel
A1  - Micheel, Burkhard
A1  - Höhne, Wolfgang
A1  - Woller, Jochen
A1  - Kempter, Gerhard
A1  - Scheller, Frieder W.
T1  - Detection of diphenylurea derivatives with biospecific interaction analysis (BIA) : Kinetic investigations
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Scheller, Frieder W.
A1  - Abuknesha, Rhamadan
T1  - Effects of organic solvents on semicontinuous immunochemical detection of coumarin derivatives
Y1  - 1995
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  - Stöcklein, Walter F. M.
A1  - Scheller, Frieder W.
T1  - Laccase : a marker enzyme for solvent modified immunoassays
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Stöcklein, Walter F. M.
A1  - Rohde, M.
A1  - Scharte, Gudrun
A1  - Behrsing, Olaf
A1  - Warsinke, Axel
A1  - Micheel, Burkhard
A1  - Scheller, Frieder W.
T1  - Sensitive detection of triazine and phenylurea pesticides in pure organic solvent by enzyme linked immunsorbent assay (ELISA): stabilities, solubilities and sensitives
Y1  - 2000
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  - 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  - 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  - Stoellner, Daniela
A1  - Scheller, Frieder W.
A1  - Warsinke, Axel
T1  - Activation of cellulose membranes with 1,1ï-carbonyldiimidazole or 1-cyano-4-4-dimethylaminopyridinium tetrafluoroborate as a basis for the development of immunosensors
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Stancík, L.
A1  - Macholán, L.
A1  - Pluhacek, I.
A1  - Scheller, Frieder W.
T1  - Biosensing of rapeseed glucosinolates using amperometric enzyme electrodes based on membrane-bound glucose oxidase or tyrosinase
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Stancik, L.
A1  - Macholán, L.
A1  - Scheller, Frieder W.
T1  - Biosensing of tyrosinase inhibitors in nonaqueous solvents
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Spricigo, Roberto
A1  - Richter, Claudia
A1  - Leimkühler, Silke
A1  - Gorton, Lo
A1  - Scheller, Frieder W.
A1  - Wollenberger, Ursula
T1  - Sulfite biosensor based on osmium redox polymer wired sulfite oxidase
N2  - A biosensor, based on a redoxactive osmium polymer and sulfite oxidase on screen-printed electrodes, is presented here as a promising method for the detection of sulfite. A catalytic oxidative current was generated when a sample containing sulfite was pumped over the carbon screen-printed electrode modified with osmium redox polymer wired sulfite oxidase. A stationary value was reached after approximately 50 s and a complete measurement lasted no more than 3 min. The electrode polarized at -0.1 V (vs. Ag vertical bar AgCl 1M KCl) permits minimizing the influence of interfering substances, since these compounds can be unspecific oxidized at higher potentials. Because of the good stability of the protein film on the electrode surface, a well functioning biosensor-flow system was possible to construct. The working stability and reproducibility were further enhanced by the addition of bovine serum albumin generating a more long-term stable and biocompatible protein environment. The optimized biosensor showed a stable signal for more than a week of operation and a coefficient of variation of 4.8% for 12 successive measurements. The lower limit of detection of the sensor was 0.5 mu M sulfite and the response was linear until 100 mu M. The high sensitivity permitted a 1:500 dilution of wine samples. The immobilization procedure and the operational conditions granted minimized interferences. Additionally, repeating the immobilization procedure to form several layers of wired SO further increased the sensitivity of such a sensor. Finally. the applicability of the developed sulfite biosensor was tested on real samples, such as white and red wines.
Y1  - 2010
UR  - http://www.sciencedirect.com/science/journal/09277757
U6  - https://doi.org/10.1016/j.colsurfa.2009.09.001
SN  - 0927-7757
ER  - 
TY  - JOUR
A1  - Spricigo, Roberto
A1  - Leimkühler, Silke
A1  - Gorton, Lo
A1  - Scheller, Frieder W.
A1  - Wollenberger, Ursula
T1  - The Electrically Wired Molybdenum Domain of Human Sulfite Oxidase is Bioelectrocatalytically Active
JF  - European journal of inorganic chemistry : a journal of ChemPubSoc Europe
N2  - We report electron transfer between the catalytic molybdenum cofactor (Moco) domain of human sulfite oxidase (hSO) and electrodes through a poly(vinylpyridine)-bound [osmium(N,N'-methyl-2,2'-biimidazole)(3)](2+/3+) complex as the electron-transfer mediator. The biocatalyst was immobilized in this low-potential redox polymer on a carbon electrode. Upon the addition of sulfite to the immobilized separate Moco domain, the generation of a significant catalytic current demonstrated that the catalytic center is effectively wired and active. The bioelectrocatalytic current of the wired separate catalytic domain reached 25% of the signal of the wired full molybdoheme enzyme hSO, in which the heme b(5) is involved in the electron-transfer pathway. This is the first report on a catalytically active wired molybdenum cofactor domain. The formal potential of this electrochemical mediator is between the potentials of the two cofactors of hSO, and as hSO can occupy several conformations in the polymer matrix, it is imaginable that electron transfer from the catalytic site to the electrode through the osmium center occurs for the hSO molecules in which the Moco domain is sufficiently accessible. The observation of catalytic oxidation currents at low potentials is favorable for applications in bioelectronic devices.
KW  - Metalloenzymes
KW  - Enzyme catalysis
KW  - Immobilization
KW  - Osmium
Y1  - 2015
U6  - https://doi.org/10.1002/ejic.201500034
SN  - 1434-1948
SN  - 1099-0682
IS  - 21
SP  - 3526
EP  - 3531
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Spricigo, Roberto
A1  - Dronov, Roman
A1  - Lisdat, Fred
A1  - Leimkühler, Silke
A1  - Scheller, Frieder W.
A1  - Wollenberger, Ursula
T1  - Electrocatalytic sulfite biosensor with human sulfite oxidase co-immobilized with cytochrome c in a polyelectrolyte-containing multilayer
N2  - An efficient electrocatalytic biosensor for sulfite detection was developed by co-immobilizing sulfite oxidase and cytochrome c with polyaniline sulfonic acid in a layer-by-layer assembly. QCM, UV-Vis spectroscopy and cyclic voltammetry revealed increasing loading of electrochemically active protein with the formation of multilayers. The sensor operates reagentless at low working potential. A catalytic oxidation current was detected in the presence of sulfite at the modified gold electrode, polarized at +0.1 V ( vs. Ag/AgCl 1 M KCl). The stability of the biosensor performance was characterized and optimized. A 17-bilayer electrode has a linear range between 1 and 60 mu M sulfite with a sensitivity of 2.19 mA M-1 sulfite and a response time of 2 min. The electrode retained a stable response for 3 days with a serial reproducibility of 3.8% and lost 20% of sensitivity after 5 days of operation. It is possible to store the sensor in a dry state for more than 2 months. The multilayer electrode was used for determination of sulfite in unspiked and spiked samples of red and white wine. The recovery and the specificity of the signals were evaluated for each sample.
Y1  - 2009
UR  - http://www.springerlink.com/content/100417
U6  - https://doi.org/10.1007/s00216-008-2432-y
SN  - 1618-2642
ER  - 
TY  - JOUR
A1  - Song, Min Ik
A1  - Bier, Frank Fabian
A1  - Scheller, Frieder W.
T1  - A method to detect superoxide radicals using teflon membrane and superoxide dismutase
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Sigolaeva, L. V.
A1  - Markower, Alexander
A1  - Eremenko, A. V.
A1  - Makhaeva, G. F.
A1  - Malygin, V. V.
A1  - Kurochkin, I. N.
A1  - Scheller, Frieder W.
T1  - Bioelectrochemical anaysis of neuropathy targes esterase activity in blood
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Shumyantseva, V. V.
A1  - Ivanov, Y. D.
A1  - Bistolas, Nikitas
A1  - Scheller, Frieder W.
A1  - Archakov, Alexander I.
A1  - Wollenberger, Ursula
T1  - Direct electron transfer of cytochrome P450 2B4 at electrodes modified with non-ionic detergent and colloidal clay nanoparticles
N2  - A method for construction of biosensors with membranous cytochrome P450 isoenzymes was developed based on clay/ detergent/protein mixed films. Thin films of sodium montmorillonite colloid with incorporated cytochrome P450 2134 (CYP2B4) with nonionic detergent were prepared on glassy carbon electrodes. The modified electrodes were electrochemically characterized, and bio-electrocatalytic reactions were followed. CYP2B4 can be reduced fast on clay- modified glassy carbon electrodes in the presence of the nonionic detergent Tween 80. In anaerobic solutions, reversible oxidation and reduction is obtained with a formal potential between -0.292 and - 0.305 V vs Ag/AgCl 1 M KCl depending on the preparation of the biosensor. In air-saturated solution, bio-electrocatalytic reduction currents can be obtained with the CYP2B4-modified electrode on addition of typical substrates such as aminopyrine and benzphetamine. This reaction was suppressed when methyrapone, an inhibitor of P450 reactions, was present. Measurement of product formation also indicates the bioelectrocatialysis by CYP2B4
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Schulmeister, Thomas
A1  - Scheller, Frieder W.
T1  - The mathematics of exponential signal amplification in amperometric three enzyme electrodes
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Schulmeister, Thomas
A1  - Rose, Jürgen
A1  - Scheller, Frieder W.
T1  - Mathematical modelling of exponential amplification in membrane-based enzyme sensors
Y1  - 1997
ER  -