TY  - JOUR
A1  - Scheller, Frieder W.
A1  - Zhang, Xiaorong
A1  - Yarman, Aysu
A1  - Wollenberger, Ulla
A1  - Gyurcsányi, Róbert E.
T1  - Molecularly imprinted polymer-based electrochemical sensors for biopolymers
JF  - Current opinion in electrochemistry
N2  - Electrochemical synthesis and signal generation dominate among the almost 1200 articles published annually on protein-imprinted polymers. Such polymers can be easily prepared directly on the electrode surface, and the polymer thickness can be precisely adjusted to the size of the target to enable its free exchange. In this architecture, the molecularly imprinted polymer (MIP) layer represents only one ‘separation plate’; thus, the selectivity does not reach the values of ‘bulk’ measurements. The binding of target proteins can be detected straightforwardly by their modulating effect on the diffusional permeability of a redox marker through the thin MIP films. However, this generates an ‘overall apparent’ signal, which may include nonspecific interactions in the polymer layer and at the electrode surface. Certain targets, such as enzymes or redox active proteins, enables a more specific direct quantification of their binding to MIPs by in situ determination of the enzyme activity or direct electron transfer, respectively.
KW  - Electropolymerization
KW  - Direct electron transfer
KW  - Redox marker
KW  - Epitope imprinting
KW  - Biomarker
Y1  - 2018
U6  - https://doi.org/10.1016/j.coelec.2018.12.005
SN  - 2451-9103
VL  - 14
SP  - 53
EP  - 59
PB  - Elsevier
CY  - Amsterdam
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  -