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  - 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  -