@article{MachatschekSchulzLendlein2018,
  author    = {Machatschek, Rainhard Gabriel and Schulz, Burkhard and Lendlein, Andreas},
  title     = {The influence of pH on the molecular degradation mechanism of PLGA},
  series = {MRS Advances},
  volume    = {3},
  journal   = {MRS Advances},
  number    = {63},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {2059-8521},
  doi       = {10.1557/adv.2018.602},
  pages     = {3883 -- 3889},
  year      = {2018},
  abstract  = {Poly[(rac-lactide)-co-glycolide] (PLGA) is used in medicine to provide mechanical support for healing tissue or as matrix for controlled drug release. The properties of this copolymer depend on the evolution of the molecular weight of the material during degradation. which is determined by the kinetics of the cleavage of hydrolysable bonds. The generally accepted description of the degradation of PLGA is a random fragmentation that is autocatalyzed by the accumulation of acidic fragments inside the bulk material. Since mechanistic studies with lactide oligomers have concluded a chain-end scission mechanism and monolayer degradation experiments with polylactide found no accelerated degradation at lower pH, we hypothesize that the impact of acidic fragments on the molecular degradation kinetics of PLGA is overestimated By means of the Langmuir monolayer degradation technique. the molecular degradation kinetics of PLGA at different pH could be determined. Protons did not catalyze the degradation of PLGA. The molecular mechanism at neutral pH and low pH is a combination of random and chainend-cut events, while the degradation under strongly alkaline conditions is determined by rapid chainend cuts. We suggest that the degradation of bulk PLGA is not catalyzed by the acidic degradation products. Instead. increased concentration of small fragments leads to accelerated mass loss via fast chain-end cut events. In the future, we aim to substantiate the proposed molecular degradation mechanism of PLGA with interfacial rheology.},
  language  = {en}
}
@article{NieWangXuetal.2019,
  author    = {Nie, Yan and Wang, Weiwei and Xu, Xun and Zou, Jie and Bhuvanesh, Thanga and Schulz, Burkhard and Ma, Nan and Lendlein, Andreas},
  title     = {Enhancement of human induced pluripotent stem cells adhesion through multilayer laminin coating},
  series = {Clinical hemorheology and microcirculation : blood flow and vessels},
  volume    = {70},
  journal   = {Clinical hemorheology and microcirculation : blood flow and vessels},
  number    = {4},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1386-0291},
  doi       = {10.3233/CH-189318},
  pages     = {531 -- 542},
  year      = {2019},
  abstract  = {Bioengineered cell substrates are a highly promising tool to govern the differentiation of stem cells in vitro and to modulate the cellular behavior in vivo. While this technology works fine for adult stem cells, the cultivation of human induced pluripotent stem cells (hiPSCs) is challenging as these cells typically show poor attachment on the bioengineered substrates, which among other effects causes substantial cell death. Thus, very limited types of surfaces have been demonstrated suitable for hiPSC cultures. The multilayer coating approach that renders the surface with diverse chemical compositions, architectures, and functions can be used to improve the adhesion of hiPSCs on the bioengineered substrates. We hypothesized that a multilayer formation based on the attraction of molecules with opposite charges could functionalize the polystyrene (PS) substrates to improve the adhesion of hiPSCs. Polymeric substrates were stepwise coated, first with dopamine to form a polydopamine (PDA) layer, second with polylysine and last with Laminin-521. The multilayer formation resulted in the variation of hydrophilicity and chemical functionality of the surfaces. Hydrophilicity was detected using captive bubble method and the amount of primary and secondary amines on the surface was quantified by fluorescent staining. The PDA layer effectively immobilized the upper layers and thereby improved the attachment of hiPSCs. Cell adhesion was enhanced on the surfaces coated with multilayers, as compared to those without PDA and/or polylysine. Moreover, hiPSCs spread well over this multilayer laminin substrate. These cells maintained their proliferation capacity and differentiation potential. The multilayer coating strategy is a promising attempt for engineering polymer-based substrates for the cultivation of hiPSCs and of interest for expanding the application scope of hiPSCs.},
  language  = {en}
}
@article{SaretiaMachatschekSchulzetal.2019,
  author    = {Saretia, Shivam and Machatschek, Rainhard Gabriel and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Reversible 2D networks of oligo(epsilon-caprolactone) at the air-water interface},
  series = {Biomedical Materials},
  volume    = {14},
  journal   = {Biomedical Materials},
  number    = {3},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {1748-6041},
  doi       = {10.1088/1748-605X/ab0cef},
  pages     = {10},
  year      = {2019},
  abstract  = {Hydroxyl terminated oligo(epsilon-caprolactone) (OCL) monolayers were reversibly cross-linked forming two dimensional networks (2D) at the air-water interface. The equilibrium reaction with glyoxal as the cross-linker is pH-sensitive. Pronounced contraction in the area of the prepared 2DOCL films in dependence of surface pressure and time revealed the process of the reaction. Cross-linking inhibited crystallization and retarded enzymatic degradation of the OCLfilm. Altering the subphase pH led to a cleavage of the covalent acetal cross-links. The reversibility of the covalent acetal cross-links was proved by observing an identical isotherm as non-cross-linked sample. Besides as model systems, these customizable reversible OCL2D networks are intended for use as pHresponsive drug delivery systems or functionalized cell culture substrates.},
  language  = {en}
}
@misc{MachatschekSchulzLendlein2018,
  author    = {Machatschek, Rainhard Gabriel and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Langmuir Monolayers as Tools to Study Biodegradable Polymer Implant Materials},
  series = {Macromolecular rapid communications},
  volume    = {40},
  journal   = {Macromolecular rapid communications},
  number    = {1},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201800611},
  pages     = {11},
  year      = {2018},
  abstract  = {Langmuir monolayers provide a fast and elegant route to analyze the degradation behavior of biodegradable polymer materials. In contrast to bulk materials, diffusive transport of reactants and reaction products in the (partially degraded) material can be neglected at the air-water interface, allowing for the study of molecular degradation kinetics in experiments taking less than a day and in some cases just a few minutes, in contrast to experiments with bulk materials that can take years. Several aspects of the biodegradation behavior of polymer materials, such as the interaction with biomolecules and degradation products, are directly observable. Expanding the technique with surface-sensitive instrumental techniques enables evaluating the evolution of the morphology, chemical composition, and the mechanical properties of the degrading material in situ. The potential of the Langmuir monolayer degradation technique as a predictive tool for implant degradation when combined with computational methods is outlined, and related open questions and strategies to overcome these challenges are pointed out.},
  language  = {en}
}
@misc{LohwasserHasslerBehrmannetal.2003,
  author    = {Lohwaßer, Roswitha and Haßler, Gerda and Behrmann, G{\"u}nter C. and Schulz, Burkhard and Mieske, Silvio},
  title     = {Portal = Knappe Kassen: Was das akademische Jahr bringt},
  volume    = {2003},
  organization    = {Universit{\"a}t Potsdam, Referat f{\"u}r Presse- und {\"O}ffentlichkeitsarbeit},
  issn      = {1618-6893},
  doi       = {10.25932/publishup-50226},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-502262},
  pages     = {40},
  year      = {2003},
  abstract  = {Aus dem Inhalt: - Knappe Kassen: Was das akademische Jahr bringt - Sparkasse finanziert Stiftungsprofessur - Chipkarte ersetzt Studentenausweis aus Papier - Unikonzert im Potsdamer Nikolaisaal},
  language  = {de}
}
@article{BhuvaneshMachatschekLysyakovaetal.2019,
  author    = {Bhuvanesh, Thanga and Machatschek, Rainhard Gabriel and Lysyakova, Liudmila and Kratz, Karl and Schulz, Burkhard and Ma, Nan and Lendlein, Andreas},
  title     = {Collagen type-IV Langmuir and Langmuir-Schafer layers as model biointerfaces to direct stem cell adhesion},
  series = {Biomedical materials : materials for tissue engineering and regenerative medicine},
  volume    = {14},
  journal   = {Biomedical materials : materials for tissue engineering and regenerative medicine},
  number    = {2},
  publisher = {Inst. of Physics Publ.},
  address   = {Bristol},
  issn      = {1748-6041},
  doi       = {10.1088/1748-605X/aaf464},
  pages     = {17},
  year      = {2019},
  abstract  = {In biomaterial development, the design of material surfaces that mimic the extra-cellular matrix (ECM) in order to achieve favorable cellular instruction is rather challenging. Collagen-type IV (Col-IV), the major scaffolding component of Basement Membranes (BM), a specialized ECM with multiple biological functions, has the propensity to form networks by self-assembly and supports adhesion of cells such as endothelial cells or stem cells. The preparation of biomimetic Col-IV network-like layers to direct cell responses is difficult. We hypothesize that the morphology of the layer, and especially the density of the available adhesion sites, regulates the cellular adhesion to the layer. The Langmuir monolayer technique allows for preparation of thin layers with precisely controlled packing density at the air-water (A-W) interface. Transferring these layers onto cell culture substrates using the Langmuir-Schafer (LS) technique should therefore provide a pathway for preparation of BM mimicking layers with controlled cell adherence properties. In situ characterization using ellipsometry and polarization modulation-infrared reflection absorption spectroscopy of Col-IV layer during compression at the A-W interface reveal that there is linear increase of surface molecule concentration with negligible orientational changes up to a surface pressure of 25 mN m(-1). Smooth and homogeneous Col-IV network-like layers are successfully transferred by LS method at 15 mN m(-1) onto poly(ethylene terephthalate) (PET), which is a common substrate for cell culture. In contrast, the organization of Col-IV on PET prepared by the traditionally employed solution deposition method results in rather inhomogeneous layers with the appearance of aggregates and multilayers. Progressive increase in the number of early adherent mesenchymal stem cells (MSCs) after 24 h by controlling the areal Col-IV density by LS transfer at 10, 15 and 20 mN m(-1) on PET is shown. The LS method offers the possibility to control protein characteristics on biomaterial surfaces such as molecular density and thereby, modulate cell responses.},
  language  = {en}
}
@article{MachatschekSchoeneRaschdorfetal.2019,
  author    = {Machatschek, Rainhard Gabriel and Sch{\"o}ne, Anne-Christin and Raschdorf, Elisa and Ihlenburg, Ramona and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Interfacial properties of morpholine-2,5-dione-based oligodepsipeptides and multiblock copolymers},
  series = {MRS Communications},
  volume    = {9},
  journal   = {MRS Communications},
  number    = {1},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {2159-6859},
  doi       = {10.1557/mrc.2019.21},
  pages     = {170 -- 180},
  year      = {2019},
  abstract  = {Oligodepsipeptides (ODPs) with alternating amide and ester bonds prepared by ring-opening polymerization of morpholine-2,5-dione derivatives are promising matrices for drug delivery systems and building blocks for multifunctional biomaterials. Here, we elucidate the behavior of three telechelic ODPs and one multiblock copolymer containing ODP blocks at the air-water interface. Surprisingly, whereas the oligomers and multiblock copolymers crystallize in bulk, no crystallization is observed at the air-water interface. Furthermore, polarization modulation infrared reflection absorption spectroscopy is used to elucidate hydrogen bonding and secondary structures in ODP monolayers. The results will direct the development of the next ODP-based biomaterial generation with tailored properties for highly sophisticated applications.},
  language  = {en}
}
@misc{MachatschekSchoeneRaschdorfetal.2019,
  author    = {Machatschek, Rainhard Gabriel and Sch{\"o}ne, Anne-Christin and Raschdorf, Elisa and Ihlenburg, Ramona and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Interfacial properties of morpholine-2,5-dione-based oligodepsipeptides and multiblock copolymers},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1106},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-46975},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-469755},
  pages     = {170 -- 180},
  year      = {2019},
  abstract  = {Oligodepsipeptides (ODPs) with alternating amide and ester bonds prepared by ring-opening polymerization of morpholine-2,5-dione derivatives are promising matrices for drug delivery systems and building blocks for multifunctional biomaterials. Here, we elucidate the behavior of three telechelic ODPs and one multiblock copolymer containing ODP blocks at the air-water interface. Surprisingly, whereas the oligomers and multiblock copolymers crystallize in bulk, no crystallization is observed at the air-water interface. Furthermore, polarization modulation infrared reflection absorption spectroscopy is used to elucidate hydrogen bonding and secondary structures in ODP monolayers. The results will direct the development of the next ODP-based biomaterial generation with tailored properties for highly sophisticated applications.},
  language  = {en}
}
@article{TarazonaMachatschekSchulzetal.2019,
  author    = {Tarazona, Natalia A. and Machatschek, Rainhard Gabriel and Schulz, Burkhard and Auxiliadora Prieto Jim{\´e}nez, M. and Lendlein, Andreas},
  title     = {Molecular Insights into the Physical Adsorption of Amphiphilic Protein PhaF onto Copolyester Surfaces},
  series = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences},
  volume    = {20},
  journal   = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences},
  number    = {9},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1525-7797},
  doi       = {10.1021/acs.biomac.9b00069},
  pages     = {3242 -- 3252},
  year      = {2019},
  abstract  = {Phasins are amphiphilic proteins located at the polymer-cytoplasm interface of bacterial polyhydroxyalkanoates (PHA). The immobilization of phasins on biomaterial surfaces is a promising way to enhance the hydrophilicity and supply cell- directing elements in bioinstructing processes. Optimizing the physical adsorption of phasins requires deep insights into molecular processes during polymer-protein interactions to preserve their structural conformation while optimizing surface coverage. Here, the assembly, organization, and stability of phasin PhaF from Pseudomonas putida at interfaces is disclosed. The Langmuir technique, combined with in situ microscopy and spectroscopic methods, revealed that PhaF forms stable and robust monolayers at different temperatures, with an almost flat orientation of its alpha-helix at the air-water interface. PhaF adsorption onto preformed monolayers of poly[(3-R-hydroxyoctanoate)-co-(3-R-hydroxyhexanoate)] (PHOHHx), yields stable mixed layers below pi = similar to 15.7 mN/m. Further insertion induces a molecular reorganization. PHOHHx with strong surface hydrophobicity is a more adequate substrate for PhaF adsorption than the less hydrophobic poly[(rac-lactide)-co-glycolide] (PLGA). The observed orientation of the main axis of the protein in relation to copolyester interfaces ensures the best exposure of the hydrophobic residues, providing a suitable coating strategy for polymer functionalization.},
  language  = {en}
}
@article{DiezTauerSchulz2006,
  author    = {Diez, Isabel and Tauer, Klaus and Schulz, Burkhard},
  title     = {Unusual polymer dispersions-polypyrrole suspensions made of rings, frames, and platelets},
  series = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft},
  volume    = {284},
  journal   = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft},
  publisher = {Springer},
  address   = {New York},
  issn      = {0303-402X},
  doi       = {10.1007/s00396-006-1521-8},
  pages     = {1431 -- 1442},
  year      = {2006},
  abstract  = {Experimental results show that the polymerization of pyrrole in the presence of beta-naphthalenesulfonic acid and different fluorosurfactants like perfluorooctanesulfonic acid, perfluorooctyldiethanolamide, and ammonium perfluorooctanoate leads to polypyrrole with special morphologies, such as rings or disks and rectangular frames or plates. The formation of these unusually shaped particles of polymer dispersions is explained by the chemical and colloidal peculiarities of the oxidative pyrrole polymerization with ammonium peroxodisulfate in aqueous medium.},
  language  = {en}
}
@misc{SchoeneRochSchulzetal.2017,
  author    = {Sch{\"o}ne, Anne-Christin and Roch, Toralf and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Evaluating polymeric biomaterial-environment interfaces by Langmuir monolayer techniques},
  series = {Interface : journal of the Royal Society},
  volume    = {14},
  journal   = {Interface : journal of the Royal Society},
  publisher = {Royal Society},
  address   = {London},
  issn      = {1742-5689},
  doi       = {10.1098/rsif.2016.1028},
  pages     = {18},
  year      = {2017},
  abstract  = {Polymeric biomaterials are of specific relevance in medical and pharmaceutical applications due to their wide range of tailorable properties and functionalities. The knowledge about interactions of biomaterials with their biological environment is of crucial importance for developing highly sophisticated medical devices. To achieve optimal in vivo performance, a description at the molecular level is required to gain better understanding about the surface of synthetic materials for tailoring their properties. This is still challenging and requires the comprehensive characterization of morphological structures, polymer chain arrangements and degradation behaviour. The review discusses selected aspects for evaluating polymeric biomaterial-environment interfaces by Langmuir monolayer methods as powerful techniques for studying interfacial properties, such as morphological and degradation processes. The combination of spectroscopic, microscopic and scattering methods with the Langmuir techniques adapted to polymers can substantially improve the understanding of their in vivo behaviour.},
  language  = {en}
}
@article{BhuvaneshSaretiaRochetal.2017,
  author    = {Bhuvanesh, Thanga and Saretia, Shivam and Roch, Toralf and Sch{\"o}ne, Anne-Christin and Rottke, Falko O. and Kratz, Karl and Wang, Weiwei and Ma, Nan and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Langmuir-Schaefer films of fibronectin as designed biointerfaces for culturing stem cells},
  series = {Polymers for advanced technologies},
  volume    = {28},
  journal   = {Polymers for advanced technologies},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1042-7147},
  doi       = {10.1002/pat.3910},
  pages     = {1305 -- 1311},
  year      = {2017},
  abstract  = {Glycoproteins adsorbing on an implant upon contact with body fluids can affect the biological response in vitro and in vivo, depending on the type and conformation of the adsorbed biomacromolecules. However, this process is poorly characterized and so far not controllable. Here, protein monolayers of high molecular cohesion with defined density are transferred onto polymeric substrates by the Langmuir-Schaefer (LS) technique and were compared with solution deposition (SO) method. It is hypothesized that on polydimethylsiloxane (PDMS), a substrate with poor cell adhesion capacity, the fibronectin (FN) layers generated by the LS and SO methods will differ in their organization, subsequently facilitating differential stem cell adhesion behavior. Indeed, atomic force microscopy visualization and immunofluorescence images indicated that organization of the FN layer immobilized on PDMS was uniform and homogeneous. In contrast, FN deposited by SO method was rather heterogeneous with appearance of structures resembling protein aggregates. Human mesenchymal stem cells showed reduced absolute numbers of adherent cells, and the vinculin expression seemed to be higher and more homogenously distributed after seeding on PDMS equipped with FN by LS in comparison with PDMS equipped with FN by SO. These divergent responses could be attributed to differences in the availability of adhesion molecule ligands such as the Arg-Gly-Asp (RGD) peptide sequence presented at the interface. The LS method allows to control the protein layer characteristics, including the thickness and the protein orientation or conformation, which can be harnessed to direct stem cell responses to defined outcomes, including migration and differentiation. Copyright (c) 2016 John Wiley \& Sons, Ltd.},
  language  = {en}
}
@article{EmmerlingOrgzallRecketal.2006,
  author    = {Emmerling, Franziska and Orgzall, Ingo and Reck, G{\"u}nter and Schulz, Burkhard W. and Stockhause, Sabine and Schulz, Burkhard},
  title     = {Structures of substituted di-aryl-1, 3,4-oxadiazole derivatives: 2,5-bis(pyridyl)- and 2,5-bis(aminophenyl)-substitution},
  series = {Journal of molecular structure},
  volume    = {800},
  journal   = {Journal of molecular structure},
  number    = {1-3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0022-2860},
  doi       = {10.1016/j.molstruc.2006.03.076},
  pages     = {74 -- 84},
  year      = {2006},
  abstract  = {Crystal structures of four different di-aryl-1,3,4-oxadiazole compounds (aryl = 2-pyridyl-, 3-pyridyl-, 2-aminophenyl-, 3-aminophenyl-) are determined. Crystallization of di(2-pyridyl)-1,3,4-oxadiazole yielded monoclinic and triclinic polymorphs. The structures are characterized by the occurrence of pi-pi interactions. Additionally, in case of the aminophenyl compounds intra- as well as intermolecular hydrogen bonds are found that influence the packing motif as well. Since these molecules are often used as ligands in metal-organic complexes similarities and differences of the molecular conformation between the molecules in the pure crystals and that of the ligands in the complexes are discussed. (c) 2006 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{RottkeSchulzRichauetal.2016,
  author    = {Rottke, Falko O. and Schulz, Burkhard and Richau, Klaus and Kratz, Karl and Lendlein, Andreas},
  title     = {An ellipsometric approach towards the description of inhomogeneous polymer-based Langmuir layers},
  series = {Beilstein journal of nanotechnology},
  volume    = {7},
  journal   = {Beilstein journal of nanotechnology},
  publisher = {Beilstein-Institut zur F{\~A}\Prderung der Chemischen Wissenschaften},
  address   = {Frankfurt, Main},
  issn      = {2190-4286},
  doi       = {10.3762/bjnano.7.107},
  pages     = {1156 -- 1165},
  year      = {2016},
  abstract  = {The applicability of nulling-based ellipsometric mapping as a complementary method next to Brewster angle microscopy (BAM) and imaging ellipsometry (IE) is presented for the characterization of ultrathin films at the air-water interface. First, the methodology is demonstrated for a vertically nonmoving Langmuir layer of star-shaped, 4-arm poly(omega-pentadecalactone) (PPDL-D4). Using nulling-based ellipsometric mapping, PPDL-D4-based inhomogeneously structured morphologies with a vertical dimension in the lower nm range could be mapped. In addition to the identification of these structures, the differentiation between a monolayer and bare water was possible. Second, the potential and limitations of this method were verified by applying it to more versatile Langmuir layers of telechelic poly[(rac-lactide)-co-glycolide]-diol (PLGA). All ellipsometric maps were converted into thickness maps by introduction of the refractive index that was derived from independent ellipsometric experiments, and the result was additionally evaluated in terms of the root mean square roughness, R-q. Thereby, a three-dimensional view into the layers was enabled and morphological inhomogeneity could be quantified.},
  language  = {en}
}
@article{SchoeneKratzSchulzetal.2016,
  author    = {Sch{\"o}ne, Anne-Christin and Kratz, Karl and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Polymer architecture versus chemical structure as adjusting tools for the enzymatic degradation of oligo(epsilon-caprolactone) based films at the air-water interface},
  series = {Polymer Degradation and Stability},
  volume    = {131},
  journal   = {Polymer Degradation and Stability},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0141-3910},
  doi       = {10.1016/j.polymdegradstab.2016.07.010},
  pages     = {114 -- 121},
  year      = {2016},
  abstract  = {The enzymatic degradation of oligo(epsilon-caprolactone) (OCL) based films at the air-water interface is investigated by Langmuir monolayer degradation (LMD) experiments to elucidate the influence of the molecular architecture and of the chemical structure on the chain scission process. For that purpose, the interactions of 2D monolayers of two star-shaped poly(epsilon-caprolactone)s (PCLs) and three linear OCL based copolyesterurethanes (P(OCL-U)) with the lipase from Pseudomonas cepacia are evaluated in comparison to linear OCL. While the architecture of star-shaped PCL Langmuir layers slightly influences their degradability compared to OCL films, significantly retarded degradations are observed for P(OCL-U) films containing urethane junction units derived from 2, 2 (4), 4-trimethyl hexamethylene diisocyanate (TMDI), hexamethylene diisocyanate (HDI) or lysine ethyl ester diisocyanate (LDI). The enzymatic degradation of the OCL based 2D structures is related to the presence of hydrophilic groups within the macromolecules rather than to the packing density of the film or to the molecular weight. The results reveal that the LMD technique allows the parallel analysis of both the film/enzyme interactions and the degradation process on the molecular level. (C) 2016 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{SarauliBorowskiPetersetal.2016,
  author    = {Sarauli, David and Borowski, Anja and Peters, Kristina and Schulz, Burkhard and Fattakhova-Rohlfing, Dina and Leimk{\"u}hler, Silke and Lisdat, Fred},
  title     = {Investigation of the pH-Dependent Impact of Sulfonated Polyaniline on Bioelectrocatalytic Activity of Xanthine Dehydrogenase},
  series = {ACS catalysis},
  volume    = {6},
  journal   = {ACS catalysis},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {2155-5435},
  doi       = {10.1021/acscatal.6b02011},
  pages     = {7152 -- 7159},
  year      = {2016},
  abstract  = {We report on the pH-dependent bioelectrocatalytic activity of the redox enzyme xanthine dehydrogenase (XDH) in the presence of sulfonated polyaniline PMSA1 (poly(2-methoxyaniline-5-sulfonic acid)-co-aniline). Ultraviolet-visible (UV-vis) spectroscopic measurements with both components in solution reveal electron transfer from the hypoxanthine (HX)-reduced enzyme to the polymer. The enzyme shows bioelectrocatalytic activity on indium tin oxide (ITO) electrodes, when the polymer is present. Depending on solution pH, different processes can be identified. It can be demonstrated that not only product-based communication with the electrode but also efficient polymer-supported bioelectrocatalysis occur. Interestingly, substrate dependent catalytic currents can be obtained in acidic and neutral solutions, although the highest activity of XDH with natural reaction partners is in the alkaline region. Furthermore, operation of the enzyme electrode without addition of the natural cofactor of XDH is feasible. Finally, macroporous ITO electrodes have been used as an immobilization platform for the fabrication of HX-sensitive electrodes. The study shows that the efficient polymer/enzyme interaction can be advantageously combined with the open structure of an electrode material of controlled pore size, resulting in good processability, stability, and defined signal transfer in the presence of a substrate.},
  language  = {en}
}
@article{SchoeneKratzSchulzetal.2016,
  author    = {Sch{\"o}ne, Anne-Christin and Kratz, Karl and Schulz, Burkhard and Lendlein, Andreas},
  title     = {The relevance of hydrophobic segments in multiblock copolyesterurethanes for their enzymatic degradation at the air-water interface},
  series = {Polymer : the international journal for the science and technology of polymers},
  volume    = {102},
  journal   = {Polymer : the international journal for the science and technology of polymers},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0032-3861},
  doi       = {10.1016/j.polymer.2016.09.001},
  pages     = {92 -- 98},
  year      = {2016},
  abstract  = {The interplay of an enzyme with a multiblock copolymer PDLCL containing two segments of different hydrophilicity and degradability is explored in thin films at the air-water interface. The enzymatic degradation was studied in homogenous Langmuir monolayers, which are formed when containing more than 40 wt\% oligo(epsilon-caprolactone) (OCL). Enzymatic degradation rates were significantly reduced with increasing content of hydrophobic oligo(omega-pentadecalactone) (OPDL). The apparent deceleration of the enzymatic process is caused by smaller portion of water-soluble degradation fragments formed from degradable OCL fragments. Beside the film degradation, a second competing process occurs after adding lipase from Pseudomonas cepacia into the subphase, namely the enrichment of the lipase molecules in the polymeric monolayer. The incorporation of the lipase into the Langmuir film is experimentally revealed by concurrent surface area enlargement and by Brewster angle microscopy (BAM). Aside from the ability to provide information about the degradation behavior of polymers, the Langmuir monolayer degradation (LMD) approach enables to investigate polymer-enzyme interactions for non-degradable polymers. (C) 2016 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{RossbergRottkeSchulzetal.2016,
  author    = {Rossberg, Joana and Rottke, Falko O. and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Enzymatic Degradation of Oligo(epsilon-caprolactone)s End-Capped with Phenylboronic Acid Derivatives at the Air-Water Interface},
  series = {Macromolecular rapid communications},
  volume    = {37},
  journal   = {Macromolecular rapid communications},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201600471},
  pages     = {1966 -- 1971},
  year      = {2016},
  abstract  = {The influence of terminal functionalization of oligo(epsilon-caprolactone)s (OCL) with phenylboronic acid pinacol ester or phenylboronic acid on the enzymatic degradation behavior at the air-water interface is investigated by the Langmuir monolayer degradation technique. While the unsubstituted OCL immediately degrades after injection of the enzyme lipase from Pseudomonas cepacia, enzyme molecules are incorporated into the films based on end-capped OCL before degradation. This incorporation of enzymes does not inhibit or suppress the film degradation, but retards it significantly. A specific binding of lipase to the polymer monolayer allows studying the enzymatic activity of bound proteins and the influence on the degradation process. The functionalization of a macromolecule with phenyl boronic acid groups is an approach to investigate their interactions with diol-containing biomolecules like sugars and to monitor their specified impact on the enzymatic degradation behavior at the air-water interface.},
  language  = {en}
}
@article{SchoeneSchulzLendlein2016,
  author    = {Sch{\"o}ne, Anne-Christin and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Stimuli Responsive and Multifunctional Polymers: Progress in Materials and Applications},
  series = {Macromolecular rapid communications},
  volume    = {37},
  journal   = {Macromolecular rapid communications},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201600650},
  pages     = {1856 -- 1859},
  year      = {2016},
  language  = {en}
}
@article{JetzschmannJagerszkiDechtriratetal.2015,
  author    = {Jetzschmann, Katharina J. and Jagerszki, Gyula and Dechtrirat, Decha and Yarman, Aysu and Gajovic-Eichelmann, Nenad and Gilsing, Hans-Detlev and Schulz, Burkhard and Gyurcsanyi, Robert E. and Scheller, Frieder W.},
  title     = {Vectorially Imprinted Hybrid Nanofilm for Acetylcholinesterase Recognition},
  series = {Advanced functional materials},
  volume    = {25},
  journal   = {Advanced functional materials},
  number    = {32},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1616-301X},
  doi       = {10.1002/adfm.201501900},
  pages     = {5178 -- 5183},
  year      = {2015},
  abstract  = {Effective recognition of enzymatically active tetrameric acetylcholinesterase (AChE) is accomplished by a hybrid nanofilm composed of a propidium-terminated self-assembled monolayer (Prop-SAM) which binds AChE via its peripheral anionic site (PAS) and an ultrathin electrosynthesized molecularly imprinted polymer (MIP) cover layer of a novel carboxylate-modified derivative of 3,4-propylenedioxythiophene. The rebinding of the AChE to the MIP/Prop-SAM nanofilm covered electrode is detected by measuring in situ the enzymatic activity. The oxidative current of the released thiocholine is dependent on the AChE concentration from approximate to 0.04 x 10(-6) to 0.4 x 10(-6)m. An imprinting factor of 9.9 is obtained for the hybrid MIP, which is among the best values reported for protein imprinting. The dissociation constant characterizing the strength of the MIP-AChE binding is 4.2 x 10(-7)m indicating the dominant role of the PAS-Prop-SAM interaction, while the benefit of the MIP nanofilm covering the Prop-SAM layer is the effective suppression of the cross-reactivity toward competing proteins as compared with the Prop-SAM. The threefold selectivity gain provided by i) the shape-specific MIP filter, ii) the propidium-SAM, iii) signal generation only by the AChE bound to the nanofilm shows promise for assessing AChE activity levels in cerebrospinal fluid.},
  language  = {en}
}
@article{TanneJeoungPengetal.2015,
  author    = {Tanne, Johannes and Jeoung, Jae-Hun and Peng, Lei and Yarman, Aysu and Dietzel, Birgit and Schulz, Burkhard and Schad, Daniel and Dobbek, Holger and Wollenberger, Ursula and Bier, Frank Fabian and Scheller, Frieder W.},
  title     = {Direct Electron Transfer and Bioelectrocatalysis by a Hexameric, Heme Protein at Nanostructured Electrodes},
  series = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis},
  volume    = {27},
  journal   = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis},
  number    = {10},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1040-0397},
  doi       = {10.1002/elan.201500231},
  pages     = {2262 -- 2267},
  year      = {2015},
  abstract  = {A nanohybrid consisting of poly(3-aminobenzenesulfonic acid-co-aniline) and multiwalled carbon nanotubes [MWCNT-P(ABS-A)]) on a gold electrode was used to immobilize the hexameric tyrosine-coordinated heme protein (HTHP). The enzyme showed direct electron transfer between the heme group of the protein and the nanostructured surface. Desorption of the noncovalently bound heme from the protein could be excluded by control measurements with adsorbed hemin on aminohexanthiol-modified electrodes. The nanostructuring and the optimised charge characteristics resulted in a higher protein coverage as compared with MUA/MU modified electrodes. The adsorbed enzyme shows catalytic activity for the cathodic H2O2 reduction and oxidation of NADH.},
  language  = {en}
}
@article{SchoeneRichauKratzetal.2015,
  author    = {Sch{\"o}ne, Anne-Christin and Richau, Klaus and Kratz, Karl and Schulz, Burkhard and Lendlein, Andreas},
  title     = {Influence of Diurethane Linkers on the Langmuir Layer Behavior of Oligo[(rac-lactide)-co-glycolide]-based Polyesterurethanes},
  series = {Macromolecular rapid communications},
  volume    = {36},
  journal   = {Macromolecular rapid communications},
  number    = {21},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201500316},
  pages     = {1910 -- 1915},
  year      = {2015},
  abstract  = {Three oligo[(rac-lactide)-co-glycolide] based polyesterurethanes (OLGA-PUs) containing different diurethane linkers are investigated by the Langmuir monolayer technique and compared to poly[(rac-lactide)-co-glycolide] (PLGA) to elucidate the influence of the diurethane junction units on hydrophilicity and packing motifs of these polymers at the air-water interface. The presence of diurethane linkers does not manifest itself in the Langmuir layer behavior both in compression and expansion experiments when monomolecular films of OLGA-PUs are spread on the water surface. However, the linker retard the evolution of morphological structures at intermediate compression level under isobaric conditions (with a surface pressure greater than 11 mN m(-1)) compared to the PLGA, independent on the chemical structure of the diurethane moiety. The layer thicknesses of both OLGA-PU and PLGA films decrease in the high compression state with decreasing surface pressure, as deduced from ellipsometric data. All films must be described with the effective medium approximation as water swollen layers.},
  language  = {en}
}
@article{SarauliXuDietzeletal.2014,
  author    = {Sarauli, David and Xu, Chenggang and Dietzel, Birgit and Schulz, Burkhard and Lisdat, Fred},
  title     = {A multilayered sulfonated polyaniline network with entrapped pyrroloquinoline quinone-dependent glucose dehydrogenase: tunable direct bioelectrocatalysis},
  series = {Journal of materials chemistry : B, Materials for biology and medicine},
  volume    = {2},
  journal   = {Journal of materials chemistry : B, Materials for biology and medicine},
  number    = {21},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2050-750X},
  doi       = {10.1039/c4tb00336e},
  pages     = {3196 -- 3203},
  year      = {2014},
  abstract  = {A feasible approach to construct multilayer films of sulfonated polyanilines - PMSA1 and PABMSA1 containing different ratios of aniline, 2-methoxyaniline-5-sulfonic acid (MAS) and 3-aminobenzoic acid (AB), with the entrapped redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH) on Au and ITO electrode surfaces, is described. The formation of layers has been followed and confirmed by electrochemical impedance spectroscopy (EIS), which demonstrates that the multilayer assembly can be achieved in a progressive and uniform manner. The gold and ITO electrodes subsequently modified with PMSA1:PQQ-GDH and PABMSA1 films are studied by cyclic voltammetry (CV) and UV-Vis spectroscopy which show a significant direct bioelectrocatalytical response to the oxidation of the substrate glucose without any additional mediator. This response correlates linearly with the number of deposited layers. Furthermore, the constructed polymer/enzyme multilayer system exhibits a rather good long-term stability, since the catalytic current response is maintained for more than 60\% of the initial value even after two weeks of storage. This verifies that a productive interaction of the enzyme embedded in the film of substituted polyaniline can be used as a basis for the construction of bioelectronic units, which are useful as indicators for processes liberating glucose and allowing optical and electrochemical transduction.},
  language  = {en}
}
@article{SarauliPetersXuetal.2014,
  author    = {Sarauli, David and Peters, Kristina and Xu, Chenggang and Schulz, Burkhard and Fattakhova-Rohlfing, Dina and Lisdat, Fred},
  title     = {3D-Electrode architectures for enhanced direct bioelectrocatalysis of pyrroloquinoline quinone-dependent glucose dehydrogenase},
  series = {ACS applied materials \& interfaces},
  volume    = {6},
  journal   = {ACS applied materials \& interfaces},
  number    = {20},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1944-8244},
  doi       = {10.1021/am5046026},
  pages     = {17887 -- 17893},
  year      = {2014},
  abstract  = {We report on the fabrication of a complex electrode architecture for efficient direct bioelectrocatalysis. In the developed procedure, the redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase entrapped in a sulfonated polyaniline [poly(2-methoxyaniline-5-sulfonic acid)-co-aniline] was immobilized on macroporous indium tin oxide (macroITO) electrodes. The use of the 3D-conducting scaffold with a large surface area in combination with the conductive polymer enables immobilization of large amounts of enzyme and its efficient communication with the electrode, leading to enhanced direct bioelectrocatalysis. In the presence of glucose, the fabricated bioelectrodes show an exceptionally high direct bioelectrocatalytical response without any additional mediator. The catalytic current is increased more than 200-fold compared to planar ITO electrodes. Together with a high long-term stability (the current response is maintained for >90\% of the initial value even after 2 weeks of storage), the transparent 3D macroITO structure with a conductive polymer represents a valuable basis for the construction of highly efficient bioelectronic units, which are useful as indicators for processes liberating glucose and allowing optical and electrochemical transduction.},
  language  = {en}
}
@article{SchoeneSchulzRichauetal.2014,
  author    = {Sch{\"o}ne, Anne-Christin and Schulz, Burkhard and Richau, Klaus and Kratz, Karl and Lendlein, Andreas},
  title     = {Characterization of Langmuir films prepared from copolyesterurethanes based on oligo(omega-pentadecalactone) and oligo(epsilon-caprolactone)segments},
  series = {Macromolecular chemistry and physics},
  volume    = {215},
  journal   = {Macromolecular chemistry and physics},
  number    = {24},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1352},
  doi       = {10.1002/macp.201400377},
  pages     = {2437 -- 2445},
  year      = {2014},
  abstract  = {A series of multiblock copolymers (PDLCL) synthesized from oligo(omega-pentadecalactone) diol (OPDL) and oligo(epsilon-caprolactone) diol (OCL), which are linked by 2,2(4), 4-trimethyl-hexamethylene diisocyanate (TMDI), is investigated by the Langmuir monolayer technique at the air-water interface. Brewster angle microscopy (BAM) and spectroscopic ellipsometry are employed to characterize the polymer film morphologies in situ. PDLCL containing >= 40 wt\% OCL segments form homogeneous Langmuir monofilms after spreading. The film elasticity modulus decreases with increasing amounts of OPDL segments in the copolymer. In contrast, the OCL-free polyesterurethane OPDL-TMDI cannot be spread to monomolecular films on the water surface properly, and movable slabs are observed by BAM even at low surface pressures. The results of the in situ morphological characterization clearly show that essential information concerning the reliability of Langmuir monolayer degradation (LMD) experiments cannot be obtained from the evaluation of the pi-A isotherms only. Consequently, in situ morphological characterization turns out to be indispensable for characterization of Langmuir layers before LMD experiments.},
  language  = {en}
}
@article{HoffmannDietzelSchulzetal.2011,
  author    = {Hoffmann, Katrin and Dietzel, Birgit and Schulz, Burkhard and Reck, Guenter and Hoffmann, Angelika and Orgzall, Ingo and Resch-Genger, Ute and Emmerling, Franziska},
  title     = {Combined structural and fluorescence studies of methyl-substituted 2,5-diphenyl-1,3,4-oxadiazoles - Relation between electronic properties and packing motifs},
  series = {Journal of molecular structure},
  volume    = {988},
  journal   = {Journal of molecular structure},
  number    = {1-3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0022-2860},
  doi       = {10.1016/j.molstruc.2010.11.071},
  pages     = {35 -- 46},
  year      = {2011},
  abstract  = {Prerequisite for the rational design of functional organic materials with tailor-made electronic properties is the knowledge of the structure-property relationship for the specific class of molecules under consideration. This encouraged us to systematically study the influence of the molecular structure and substitution pattern of aromatically substituted 1,3,4-oxadiazoles on the electronic properties and packing motifs of these molecules and on the interplay of these factors. For this purpose, seven diphenyl-oxadiazoles equipped with methyl substituents in the ortho- and meta-position(s) were synthesized and characterized. Absorption and fluorescence spectra in solution served here as tools to monitor substitution-induced changes in the electronic properties of the individual molecules whereas X-ray and optical measurements in the solid state provided information on the interplay of electronic and packing effects. In solution, the spectral position of the absorption maximum, the size of Stokes shift, and the fluorescence quantum yield are considerably affected by ortho-substitution in three or four ortho-positions. This results in blue shifted absorption bands, increased Stokes shifts, and reduced fluorescence quantum yields whereas the spectral position and vibrational structure of the emission bands remain more or less unaffected. In the crystalline state, however, the spectral position and shape of the emission bands display a strong dependence on the molecular structure and/or packing motifs that seem to control the amount of dye-dye-interactions. These observations reveal the limited value of commonly reported absorption and fluorescence measurements in solution for a straightforward comparison of spectroscopic results with single X-ray crystallography. This underlines the importance of solid state spectroscopic studies for a better understanding of the interplay of electronic effects and molecular order.},
  language  = {en}
}
@article{BanksNishiyamaHasebeetal.2011,
  author    = {Banks, Jo Ann and Nishiyama, Tomoaki and Hasebe, Mitsuyasu and Bowman, John L. and Gribskov, Michael and dePamphilis, Claude and Albert, Victor A. and Aono, Naoki and Aoyama, Tsuyoshi and Ambrose, Barbara A. and Ashton, Neil W. and Axtell, Michael J. and Barker, Elizabeth and Barker, Michael S. and Bennetzen, Jeffrey L. and Bonawitz, Nicholas D. and Chapple, Clint and Cheng, Chaoyang and Correa, Luiz Gustavo Guedes and Dacre, Michael and DeBarry, Jeremy and Dreyer, Ingo and Elias, Marek and Engstrom, Eric M. and Estelle, Mark and Feng, Liang and Finet, Cedric and Floyd, Sandra K. and Frommer, Wolf B. and Fujita, Tomomichi and Gramzow, Lydia and Gutensohn, Michael and Harholt, Jesper and Hattori, Mitsuru and Heyl, Alexander and Hirai, Tadayoshi and Hiwatashi, Yuji and Ishikawa, Masaki and Iwata, Mineko and Karol, Kenneth G. and Koehler, Barbara and Kolukisaoglu, Uener and Kubo, Minoru and Kurata, Tetsuya and Lalonde, Sylvie and Li, Kejie and Li, Ying and Litt, Amy and Lyons, Eric and Manning, Gerard and Maruyama, Takeshi and Michael, Todd P. and Mikami, Koji and Miyazaki, Saori and Morinaga, Shin-ichi and Murata, Takashi and M{\"u}ller-R{\"o}ber, Bernd and Nelson, David R. and Obara, Mari and Oguri, Yasuko and Olmstead, Richard G. and Onodera, Naoko and Petersen, Bent Larsen and Pils, Birgit and Prigge, Michael and Rensing, Stefan A. and Mauricio Riano-Pachon, Diego and Roberts, Alison W. and Sato, Yoshikatsu and Scheller, Henrik Vibe and Schulz, Burkhard and Schulz, Christian and Shakirov, Eugene V. and Shibagaki, Nakako and Shinohara, Naoki and Shippen, Dorothy E. and Sorensen, Iben and Sotooka, Ryo and Sugimoto, Nagisa and Sugita, Mamoru and Sumikawa, Naomi and Tanurdzic, Milos and Theissen, Guenter and Ulvskov, Peter and Wakazuki, Sachiko and Weng, Jing-Ke and Willats, William W. G. T. and Wipf, Daniel and Wolf, Paul G. and Yang, Lixing and Zimmer, Andreas D. and Zhu, Qihui and Mitros, Therese and Hellsten, Uffe and Loque, Dominique and Otillar, Robert and Salamov, Asaf and Schmutz, Jeremy and Shapiro, Harris and Lindquist, Erika and Lucas, Susan and Rokhsar, Daniel and Grigoriev, Igor V.},
  title     = {The selaginella genome identifies genetic changes associated with the evolution of vascular plants},
  series = {Science},
  volume    = {332},
  journal   = {Science},
  number    = {6032},
  publisher = {American Assoc. for the Advancement of Science},
  address   = {Washington},
  issn      = {0036-8075},
  doi       = {10.1126/science.1203810},
  pages     = {960 -- 963},
  year      = {2011},
  abstract  = {Vascular plants appeared similar to 410 million years ago, then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes. We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported. By comparing gene content in evolutionarily diverse taxa, we found that the transition from a gametophyte- to a sporophyte-dominated life cycle required far fewer new genes than the transition from a nonseed vascular to a flowering plant, whereas secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in posttranscriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the trans-acting small interfering RNA pathway, and extensive RNA editing of organellar genes.},
  language  = {en}
}
@article{SarauliXuDietzeletal.2012,
  author    = {Sarauli, David and Xu, Chenggang and Dietzel, Birgit and Stiba, Konstanze and Leimk{\"u}hler, Silke and Schulz, Burkhard and Lisdat, Fred},
  title     = {Thin films of substituted polyanilines interactions with biomolecular systems},
  series = {Soft matter},
  volume    = {8},
  journal   = {Soft matter},
  number    = {14},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1744-683X},
  doi       = {10.1039/c2sm07261k},
  pages     = {3848 -- 3855},
  year      = {2012},
  abstract  = {We use substituted polyanilines for the construction of new polymer electrodes for interaction studies with the redox protein cytochrome c (cyt c) and the enzyme sulfite oxidase (SO). For these purposes four different polyaniline copolymers are chemically synthesized. Three of them are copolymers, containing 2-methoxyaniline-5-sulfonic acid with variable ratios of aniline; the fourth copolymer consists of 3-amino-benzoic acid and aniline. The results show that all polymers are suitable for being immobilized as thin stable films on gold wire and indium tin oxide (ITO) electrode surfaces from DMSO solution. This can be demonstrated by cyclic voltammetry and UV-Vis spectroscopy measurements. Moreover, cyt c can be electrochemically detected not only in solution, but also immobilized on top of the polymer films. Furthermore, the appearance of a significant catalytic current has been demonstrated for the sulfonated polyanilines, when the polymer-coated protein electrode is being measured upon addition of sulfite oxidase, confirming the establishment of a bioanalytical signal chain. Best results have been obtained for the polymer with highest sulfonation grade. The redox switching of the polymer by the enzymatic reaction can also be analyzed by following the spectral properties of the polymer electrode.},
  language  = {en}
}
@article{TurhanSaracGencturketal.2012,
  author    = {Turhan, Metehan C. and Sarac, A. Sezai and Gencturk, Asli and Gilsing, Hans-Detlev and Faltz, Heike and Schulz, Burkhard},
  title     = {Electrochemical impedance characterization and potential dependence of poly[3,4-(2,2-dibutylpropylenedioxy)thiophene] nanostructures on single carbon fiber microelectrode},
  series = {Synthetic metals : the journal of electronic polymers and electronic molecular materials},
  volume    = {162},
  journal   = {Synthetic metals : the journal of electronic polymers and electronic molecular materials},
  number    = {5-6},
  publisher = {Elsevier},
  address   = {Lausanne},
  issn      = {0379-6779},
  doi       = {10.1016/j.synthmet.2012.01.012},
  pages     = {511 -- 515},
  year      = {2012},
  abstract  = {The electropolymerization of 3,4-(2,2-dibutylpropylenedioxy)thiophene (ProDOT-Bu-2) onto single carbon fiber microelectrode (SCFME) was conducted in acetonitrile (ACN) containing sodium perchlorate (NaClO4) as electrolyte and investigated by cyclic voltammetry (CV). The nanostructured films of poly[3,4-(2,2-dibutyl-propyleneclioxy)thiophene] (PProDOT-Bu-2) which were depositing showed complete reversible redox behavior in monomer-free electrolyte solution. The capacitive behavior of the films was investigated by electrochemical impedance spectroscopy (EIS) at applied potentials from 0.1 V to 1.3 V. The analysis by equivalent circuit modeling revealed an applied potential around 0.4V to be most suitable for the system PProDOT-Bu-2/SCFME as a double layer supercapacitor component inducing a double layer capacitance C-d, value of 62 mFcm(-2).},
  language  = {en}
}
@article{GulerGilsingSchulzetal.2012,
  author    = {Guler, Fatma G. and Gilsing, Hans-Detlev and Schulz, Burkhard and Sarac, A. Sezai},
  title     = {Impedance and morphology of hydroxy- and chloro-functionalized poly(3,4-propylenedioxythiophene) nanostructures},
  series = {Journal of nanoscience and nanotechnolog},
  volume    = {12},
  journal   = {Journal of nanoscience and nanotechnolog},
  number    = {10},
  publisher = {American Scientific Publ.},
  address   = {Valencia},
  issn      = {1533-4880},
  doi       = {10.1166/jnn.2012.6594},
  pages     = {7869 -- 7878},
  year      = {2012},
  abstract  = {The new 3,4-propylenedioxythiophenes (ProDOT) bearing hydroxy- or chloro-functionalized side chains of varying length and polarity were synthesized and electropolymerized on single carbon fiber microelectrode (SCFME) using cyclo-voltammetry. Electrochemical impedance spectroscopy (EIS) revealed highest capacitance values for the hydroxy-functionalized Poly 5 carrying a side chain of medium length. The EIS data were fitted with an equivalent electrical circuit giving a good correlation. AFM analysis of the topography showed higher roughness values for Poly 5 than for the two other polymers bearing longer side chains. Due to their reactive end groups the polymers should be useful for post-polymerization functionalization of the electrode surface.},
  language  = {en}
}
@article{EmmerlingOrgzallDietzeletal.2012,
  author    = {Emmerling, Franziska and Orgzall, Ingo and Dietzel, Birgit and Schulz, Burkhard and Larrucea, Julen},
  title     = {Ordering the amorphous - Structures in PBD LED materials},
  series = {Journal of molecular structure},
  volume    = {1030},
  journal   = {Journal of molecular structure},
  number    = {23},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0022-2860},
  doi       = {10.1016/j.molstruc.2012.04.040},
  pages     = {209 -- 215},
  year      = {2012},
  abstract  = {The class of 2,5 disubstituted-1,3,4-oxadiazoles containing a biphenyl unit on one side is intensively used as electron transport materials to enhance the performance of organic light emitting diodes (OLEDs). In contrast to the ongoing research on these materials insights in their structure-property relationships are still incomplete. To overcome the structural tentativeness and ambiguities the crystal structures of 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, that of the related compound 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole and of 2-(4-biphenylyl)-5-(2,6-dimethylphenyl)-1,3,4-oxadiazole are determined. A comparison with the results of GAUSSIAN03 calculations and similar compounds in the Cambridge Structural Database leads to a profound characterization.},
  language  = {en}
}
@article{SarauliXuDietzeletal.2013,
  author    = {Sarauli, David and Xu, Chenggang and Dietzel, Birgit and Schulz, Burkhard and Lisdat, Fred},
  title     = {Differently substituted sulfonated polyanilines - the role of polymer compositions in electron transfer with pyrroloquinoline quinone-dependent glucose dehydrogenase},
  series = {Acta biomaterialia},
  volume    = {9},
  journal   = {Acta biomaterialia},
  number    = {9},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {1742-7061},
  doi       = {10.1016/j.actbio.2013.06.008},
  pages     = {8290 -- 8298},
  year      = {2013},
  abstract  = {Sulfonated polyanilines have become promising building blocks in the construction of biosensors, and therefore we use here differently substituted polymer forms to investigate the role of their structural composition and properties in achieving a direct electron transfer with the redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH). To this end, new copolymers containing different ratios of 2-methoxyaniline-5-sulfonic acid (MAS), 3-aminobenzenesulfonic acid (ABS) and 3-aminobenzoic acid (AB) units have been chemically synthesized. All polymers have been studied with respect to their ability to react directly with PQQ-GDH. This interaction has been monitored initially in solution, and subsequently on electrode surfaces. The results show that only copolymers with MAS and aniline units can directly react with PQQ-GDH in solution; the background can be mainly ascribed to the emeraldine salt redox state of the polymer, allowing rather easy reduction. However, when polymers and the enzyme are immobilized on the surface of carbon nanotube-containing electrodes, direct bioelectrocatalysis is also feasible in the case of copolymers composed of ABS/AB and MAS/AB units, existing initially in pernigraniline base form. This verifies that a productive interaction of the enzyme with differently substituted polymers is feasible when the electrode potential can be used to drive the reaction towards the oxidation of the substrate-reduced enzyme. These results clearly demonstrate that enzyme electrodes based on sulfonated polyanilines and direct bioelectrocatalysis can be successfully constructed.},
  language  = {en}
}
@article{SchulzDietzelOrgzalletal.2009,
  author    = {Schulz, Burkhard and Dietzel, Birgit and Orgzall, Ingo and Diez, Isabel and Xu, Chenggang},
  title     = {Aspects of morphology control during the oxidative synthesis of electrically conducting polymers},
  issn      = {0954-0083},
  doi       = {10.1177/0954008309339933},
  year      = {2009},
  abstract  = {The formation of micro- and nanostructures during the oxidative polymerization of polypyrrole and polyaniline is investigated using different sulfonic acid dopants. Rod- or tube-like structures are found in polypyrrole as well as in polyaniline without addition of further compounds to the initial reaction mixture of monomer, dopant and oxidant. In these cases, always a crystalline precursor complex composed of a dopand molecule and the pure monomer (aniline) or a trimeric moiety (pyrrole) serves as in-situ template. In most cases the surface of the growing polymer is covered by secondary structures with much smaller sizes so that a hierarchical order of structures at different length scales results. Corresponding model considerations for the polymerization process are outlined. Additionally, unusual structures like platelets, frames, rings, or ribbons are observed in the polypyrrole synthesis in the presence of fluorosurfactants.},
  language  = {en}
}
@article{SaracGencturkGilsingetal.2009,
  author    = {Sarac, A. Sezai and Gencturk, Asli and Gilsing, Hans-Detlev and Schulz, Burkhard and Turhan, C. Metehan},
  title     = {Effect of electrolyte on the electropolymerization of 2,2-dibutyl-3,4-propylenedioxythiophene on carbon fiber microelectrodes},
  issn      = {1533-4880},
  doi       = {10.1166/Jnn.2009.027},
  year      = {2009},
  abstract  = {Electrocoating of 2,2 dibutylpropylene dioxythiophene on carbon fiber microelectrodes (CFMEs) in different electrolytes in acetonitrile was performed, and surface morphology and electrochemical impedance spectroscopic investigation has been carried out. Impedance spectra showed the typical form of Z(IM) versus Z(RE) for transmission- line at frequencies 10 Hz, with transition to almost pure capacitive behaviour down to 10 mHz (the lower limit of frequency scan).},
  language  = {en}
}
@article{OrgzallFrancoSchulz2006,
  author    = {Orgzall, Ingo and Franco, Olga and Schulz, Burkhard},
  title     = {High pressure structural investigations of 2,5-di(4-pyridyl)-1,3,4-oxadiazole - importance of strain studies for the description of intermolecular interactions},
  doi       = {10.1088/0953-8984/18/23/001},
  year      = {2006},
  abstract  = {Results of a high pressure x-ray study of 2,5-di(4-pyridyl)-1,3,4-oxadiazole up to 2.5 GPa are presented and discussed. Parameters for the Murnaghan equation of state are derived. The bulk modulus amounts to K-0 = 4.6 +/- 0.3 GPa and its pressure derivative to K-0' = 7.4 +/- 0.6. These values are comparable to values of other diphenyl-1,3,4- oxadiazoles. The anisotropy of the compression is analysed using the strain tensor and discussed based on the anisotropy of the intermolecular interactions},
  language  = {en}
}
@article{ZhuSchulzBrumaetal.1996,
  author    = {Zhu, Shigen and Schulz, Burkhard and Bruma, Maria and Brehmer, Ludwig},
  title     = {Comparative study of the thermal properties of related aromatic polyhydrazides and poly(1,3,4-oxadiazole)s},
  issn      = {1042-7147},
  doi       = {10.1002/(SICI)1099-1581(199612)7:12<879::AID-PAT600>3.0.CO;2-X},
  year      = {1996},
  language  = {en}
}
@article{SchulzKnochenhauerBrehmeretal.1994,
  author    = {Schulz, Burkhard and Knochenhauer, Gerald and Brehmer, Ludwig and Janietz, Silvia},
  title     = {Stuctures and properties of aromatic poly(1,3,4-oxadiazole)s},
  year      = {1994},
  language  = {en}
}
@article{MercerMcKenzieBrumaetal.1994,
  author    = {Mercer, Frank W. and McKenzie, M. and Bruma, Maria and Schulz, Burkhard},
  title     = {Synthesis and properties of fluorinated polyimides and fluorinated poly(imide-amide)s containing pendent cyano groups},
  year      = {1994},
  language  = {en}
}
@article{SchulzStillerZetzscheetal.1994,
  author    = {Schulz, Burkhard and Stiller, Burkhard and Zetzsche, Thomas and Knochenhauer, Gerald and Dietel, Reinhard and Brehmer, Ludwig},
  title     = {Crystal structure of 2,5-Di(4- methoxycarbonyl-phenyl)-1,3,4-oxadiazole characterized by AFM and IR- spectroscopy},
  year      = {1994},
  language  = {en}
}
@article{BrumaMercerSchulzetal.1994,
  author    = {Bruma, Maria and Mercer, Frank W. and Schulz, Burkhard and Dietel, Reinhard and Fitch, J. and Cassidy, Peter},
  title     = {Study of crosslinking process in fluorinated poly(imide-amide)s containing pendant cyano groups},
  year      = {1994},
  language  = {en}
}
@article{BrumaMercerSchulzetal.1994,
  author    = {Bruma, Maria and Mercer, Frank W. and Schulz, Burkhard and Dietel, Reinhard and Neumann, Werner},
  title     = {Fluorinated poly(benzoxazole-imide)s},
  year      = {1994},
  language  = {en}
}
@article{BrumaMercerSchulzetal.1994,
  author    = {Bruma, Maria and Mercer, Frank W. and Schulz, Burkhard and Dietel, Reinhard and Fitch, J. and Cassidy, Peter},
  title     = {Study of crosslinking process in fluorinated poly(imide-amide)s containing pendant cyano groups},
  year      = {1994},
  language  = {en}
}
@article{Schulz1994,
  author    = {Schulz, Burkhard},
  title     = {Struktur und Eigenschaften d{\"u}nner Schichten aus aromatischen Poly(1,3,4- oxadiazol)en},
  year      = {1994},
  language  = {de}
}
@article{Schulz1994,
  author    = {Schulz, Burkhard},
  title     = {New aspects of the solid-state structures and electrochemical properties of aromatic Poly(1,3,4- Oxadiazole)s},
  year      = {1994},
  language  = {en}
}
@article{Schulz1994,
  author    = {Schulz, Burkhard},
  title     = {Neue thermostabile Polyheterocyclen},
  year      = {1994},
  language  = {de}
}
@article{Schulz1994,
  author    = {Schulz, Burkhard},
  title     = {Eine neue Synthesevariante f{\"u}r aromatische Poly(1,3,4-oxadiazole)},
  year      = {1994},
  language  = {de}
}
@article{SchulzJanietz1994,
  author    = {Schulz, Burkhard and Janietz, Silvia},
  title     = {Electrochemical studies on thin films of poly(arylene 1,3,4-oxadiazole)s},
  year      = {1994},
  language  = {en}
}
@article{JanietzSchulz1994,
  author    = {Janietz, Silvia and Schulz, Burkhard},
  title     = {Electrochemical studies on thin films of poly(arylene-1,3,4-oxadiazole)s},
  year      = {1994},
  language  = {en}
}
@article{BrumaSchulzMercer1994,
  author    = {Bruma, Maria and Schulz, Burkhard and Mercer, Frank W.},
  title     = {Synthesis and characterization of fluorinated poly(imide-pyridazine- amide)s},
  year      = {1994},
  language  = {en}
}
@article{BauerSchulzBrehmeretal.1995,
  author    = {Bauer, J. and Schulz, Burkhard and Brehmer, Ludwig and B{\"o}tcher, M. and Jagdhold, U. and H{\"o}ppner, K. and Kulesch, A. and Dietzel, Birgit},
  title     = {Anwendung von Langmuir-Blodgett-Schichten als Resist f{\"u}r die Niederspannungs-Elektronenstrahl-Lithografie},
  year      = {1995},
  language  = {de}
}