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 - Caserta, Giorgio A1 - Yarman, Aysu A1 - Supala, Eszter A1 - Tadjoung Waffo, Armel Franklin A1 - Wollenberger, Ulla A1 - Gyurcsanyi, Robert E. A1 - Zebger, Ingo A1 - Scheller, Frieder W. T1 - "Out of Pocket" protein binding BT - a dilemma of epitope imprinted polymers revealed for human hemoglobin JF - Chemosensors N2 - The epitope imprinting approach applies exposed peptides as templates to synthesize Molecularly Imprinted Polymers (MIPs) for the recognition of the parent protein. While generally the template protein binding to such MIPs is considered to occur via the epitope-shaped cavities, unspecific interactions of the analyte with non-imprinted polymer as well as the detection method used may add to the complexity and interpretation of the target rebinding. To get new insights on the effects governing the rebinding of analytes, we electrosynthesized two epitope-imprinted polymers using the N-terminal pentapeptide VHLTP-amide of human hemoglobin (HbA) as the template. MIPs were prepared either by single-step electrosynthesis of scopoletin/pentapeptide mixtures or electropolymerization was performed after chemisorption of the cysteine extended VHLTP peptide. Rebinding of the target peptide and the parent HbA protein to the MIP nanofilms was quantified by square wave voltammetry using a redox probe gating, surface enhanced infrared absorption spectroscopy, and atomic force microscopy. While binding of the pentapeptide shows large influence of the amino acid sequence, all three methods revealed strong non-specific binding of HbA to both polyscopoletin-based MIPs with even higher affinities than the target peptides. KW - Molecularly Imprinted Polymers KW - epitope imprinting KW - non-specific KW - binding KW - redox gating KW - SEIRA spectroelectrochemistry Y1 - 2021 U6 - https://doi.org/10.3390/chemosensors9060128 SN - 2227-9040 VL - 9 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Menger, Marcus A1 - Yarman, Aysu A1 - Erdössy, Júlia A1 - Yildiz, Huseyin Bekir A1 - Gyurcsányi, Róbert E. A1 - Scheller, Frieder W. T1 - MIPs and Aptamers for Recognition of Proteins in Biomimetic Sensing JF - Biosensors : open access journal N2 - Biomimetic binders and catalysts have been generated in order to substitute the biological pendants in separation techniques and bioanalysis. The two major approaches use either "evolution in the test tube" of nucleotides for the preparation of aptamers or total chemical synthesis for molecularly imprinted polymers (MIPs). The reproducible production of aptamers is a clear advantage, whilst the preparation of MIPs typically leads to a population of polymers with different binding sites. The realization of binding sites in the total bulk of the MIPs results in a higher binding capacity, however, on the expense of the accessibility and exchange rate. Furthermore, the readout of the bound analyte is easier for aptamers since the integration of signal generating labels is well established. On the other hand, the overall negative charge of the nucleotides makes aptamers prone to non-specific adsorption of positively charged constituents of the sample and the "biological" degradation of non-modified aptamers and ionic strength-dependent changes of conformation may be challenging in some application. KW - biomimetic recognition elements KW - aptamers KW - molecularly imprinted polymers KW - chemical sensors KW - aptasensors KW - in vitro selection KW - SELEX Y1 - 2016 U6 - https://doi.org/10.3390/bios6030035 SN - 2079-6374 VL - 6 SP - 4399 EP - 4413 PB - MDPI CY - Basel ER - TY - GEN A1 - Menger, Marcus A1 - Yarman, Aysu A1 - Erdőssy, Júlia A1 - Yildiz, Huseyin Bekir A1 - Gyurcsányi, Róbert E. A1 - Scheller, Frieder W. T1 - MIPs and aptamers for recognition of proteins in biomimetic sensing N2 - Biomimetic binders and catalysts have been generated in order to substitute the biological pendants in separation techniques and bioanalysis. The two major approaches use either "evolution in the test tube" of nucleotides for the preparation of aptamers or total chemical synthesis for molecularly imprinted polymers (MIPs). The reproducible production of aptamers is a clear advantage, whilst the preparation of MIPs typically leads to a population of polymers with different binding sites. The realization of binding sites in the total bulk of the MIPs results in a higher binding capacity, however, on the expense of the accessibility and exchange rate. Furthermore, the readout of the bound analyte is easier for aptamers since the integration of signal generating labels is well established. On the other hand, the overall negative charge of the nucleotides makes aptamers prone to non-specific adsorption of positively charged constituents of the sample and the "biological" degradation of non-modified aptamers and ionic strength-dependent changes of conformation may be challenging in some application. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 357 KW - biomimetic recognition elements KW - aptamers KW - molecularly imprinted polymers KW - chemical sensors KW - aptasensors KW - in vitro selection KW - SELEX Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400496 ER - TY - CHAP A1 - Lück, Erika A1 - Balderjahn, Ingo A1 - Kamm, Birgit A1 - Greil, Holle A1 - Wallschläger, Hans-Dieter A1 - Jessel, Beate A1 - Böckmann, Christine A1 - Oberhänsli, Roland A1 - Soyez, Konrad A1 - Schmeer, Ernst A1 - Blumenstein, Oswald A1 - Berndt, Klaus-Peter A1 - Edeling, Thomas A1 - Friedrich, Sabine A1 - Kaden, Klaus A1 - Scheller, Frieder W. A1 - Petersen, Hans-Georg A1 - Asche, Hartmut A1 - Bronstert, Axel A1 - Giest, Hartmut A1 - Gaedke, Ursula A1 - Löhmannsröben, Hans-Gerd A1 - Jeltsch, Florian A1 - Jänkel, Ralph A1 - Gzik, Axel A1 - Bork, Hans-Rudolf A1 - Bork, Hans-Rudolf T1 - Umweltforschung für das Land Brandenburg : Arbeitsgruppen und Professuren Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-3797 ER - TY - CHAP A1 - Asche, Hartmut A1 - Böckmann, Christine A1 - Laue, Steffen A1 - Löhmannsröben, Hans-Gerd A1 - Lemke, Matthias A1 - Schober, Lars A1 - Reich, Oliver A1 - Lück, Erika A1 - Schütte, Marc A1 - Domsch, Horst A1 - Makower, Alexander A1 - Scheller, Frieder W. A1 - Stöcklein, Wolfgang A1 - Wollenberger, Ursula A1 - Schultze, Rainer A1 - Hengstermann, Theo A1 - Schael, Frank T1 - Umweltforschung für das Land Brandenburg : Projekt Umweltanalytik / Umweltmeßtechnik / Informationssysteme Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-3862 SP - 176 EP - 227 ER -