TY  - JOUR
A1  - Yarman, Aysu
A1  - Scheller, Frieder W.
T1  - Coupling biocatalysis with molecular imprinting in a biomimetic sensor
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
KW  - biomimetic sensors
KW  - electropolymers
KW  - enzymes
KW  - hierarchical structures
KW  - molecularly imprinted polymers
Y1  - 2013
U6  - https://doi.org/10.1002/anie.201305368
SN  - 1433-7851
SN  - 1521-3773
VL  - 52
IS  - 44
SP  - 11521
EP  - 11525
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bosserdt, Maria
A1  - Gajovic-Eichelman, Nenad
A1  - Scheller, Frieder W.
T1  - Modulation of direct electron transfer of cytochrome c by use of a molecularly imprinted thin film
JF  - Analytical & bioanalytical chemistry
N2  - We describe the preparation of a molecularly imprinted polymer film (MIP) on top of a self-assembled monolayer (SAM) of mercaptoundecanoic acid (MUA) on gold, where the template cytochrome c (cyt c) participates in direct electron transfer (DET) with the underlying electrode. To enable DET, a non-conductive polymer film is electrodeposited from an aqueous solution of scopoletin and cyt c on to the surface of a gold electrode previously modified with MUA. The electroactive surface concentration of cyt c was 0.5 pmol cm(-2). In the absence of the MUA layer, no cyt c DET was observed and the pseudo-peroxidatic activity of the scopoletin-entrapped protein, assessed via oxidation of Ampliflu red in the presence of hydrogen peroxide, was only 30 % of that for the MIP on MUA. This result indicates that electrostatic adsorption of cyt c by the MUA-SAM substantially increases the surface concentration of cyt c during the electrodeposition step, and is a prerequisite for the productive orientation required for DET. After template removal by treatment with sulfuric acid, rebinding of cyt c to the MUA-MIP-modified electrode occurred with an affinity constant of 100,000 mol(-1) L, a value three times higher than that determined by use of fluorescence titration for the interaction between scopoletin and cyt c in solution. The DET of cyt c in the presence of myoglobin, lysozyme, and bovine serum albumin (BSA) reveals that the MIP layer suppresses the effect of competing proteins.
KW  - Cytochrome c
KW  - Molecularly imprinted polymer film
KW  - Mercaptoundecanoic acid
KW  - Direct electron transfer
KW  - Scopoletin (7-hydroxy-6-methoxycoumarin)
Y1  - 2013
U6  - https://doi.org/10.1007/s00216-013-7009-8
SN  - 1618-2642
VL  - 405
IS  - 20
SP  - 6437
EP  - 6444
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Yarman, Aysu
A1  - Wollenberger, Ursula
A1  - Scheller, Frieder W.
T1  - Sensors based on cytochrome P450 and CYP mimicking systems
JF  - ELECTROCHIMICA ACTA
N2  - Cytochrome P450 enzymes (CYPs) act on more than 90 percent of all drugs currently on the market. The catalytic cycle requires electron supply to the heme iron in the presence of oxygen. Electrochemistry allows to characterise the reaction mechanism of these redox enzymes by observing the electron transfer in real time. According to the number of publications on protein electrochemistry CYP has the third position after glucose oxidase and cytochrome c. CYP based enzyme electrodes for the quantification of drugs, metabolites or pesticides have been developed using different iso-enzymes. A crucial step in the sensor development is the efficiency of coupling the biocatalytic systems with the electrode is. In the 1970s the direct electron transfer of heme and heme peptides called microperoxidases (MPs) was used as model of oxidoreductases. They exhibit a broad substrate spectrum including hydroxylation of selected aromatic substrates, demethylation and epoxidation by means of hydrogen peroxide. It overlaps with that of P450 making heme and MPs to alternate recognition elements in biosensors for the detection of typical CYP substrates. In these enzyme electrodes the signal is generated by the conversion of all substrates thus representing in complex media an overall parameter. By combining the biocatalytic substrate conversion with selective binding to a molecularly imprinted polymer layer the specificity has been improved. Here we discuss different approaches of biosensors based on CYP, microperoxidases and catalytically active MIPs and discuss their potential as recognition elements in biosensors. The performance of these sensors and their further development are discussed. (C) 2013 Elsevier Ltd. All rights reserved.
KW  - Cytochrome P450
KW  - Microperoxidases
KW  - Catalytically active molecularly imprinted polymers
KW  - Biosensors
KW  - Personalised medicine
Y1  - 2013
U6  - https://doi.org/10.1016/j.electacta.2013.03.154
SN  - 0013-4686
SN  - 1873-3859
VL  - 110
SP  - 63
EP  - 72
PB  - PERGAMON-ELSEVIER SCIENCE LTD
CY  - OXFORD
ER  -