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  - 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  -