TY - JOUR A1 - Krüger, Tobias A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Linker, Torsten T1 - Simple Synthesis of gamma-Spirolactams by Birch Reduction of Benzoic Acids JF - European journal of organic chemistry N2 - A convenient synthesis of gamma-spirolactams in only two steps was developed. Birch reduction of benzoic acids and immediate alkylation with chloroacetonitrile afforded cyclohexadienes in high yields. The products could be isolated by crystallization on a large scale in analytically pure form. Subsequent hydrogenation with platinum(IV) oxide as the catalyst reduced the nitrile functionality and the double bonds in the same step with excellent stereoselectivity. The relative configurations were determined unequivocally by X-ray analyses. Direct cyclization of the intermediary formed amino acids afforded the desired gamma-spirolactams in excellent overall yields. The procedure is characterized by few steps, cheap reagents, and can be performed on a large scale, interesting for industrial processes. KW - Diastereoselectivity KW - Hydrogenation KW - Lactams KW - Reduction KW - Synthetic methods Y1 - 2016 U6 - https://doi.org/10.1002/ejoc.201601650 SN - 1434-193X SN - 1099-0690 IS - 6 SP - 1074 EP - 1077 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schmidt, Burkhard A1 - Lorenz, Ulf T1 - WavePacket BT - a Matlab package for numerical quantum dynamics. I: Closed quantum systems and discrete variable representations JF - Computer physics communications : an international journal devoted to computational physics and computer programs in physics N2 - WavePacket is an open-source program package for the numerical simulation of quantum-mechanical dynamics. It can be used to solve time-independent or time-dependent linear Schrödinger and Liouville–von Neumann-equations in one or more dimensions. Also coupled equations can be treated, which allows to simulate molecular quantum dynamics beyond the Born–Oppenheimer approximation. Optionally accounting for the interaction with external electric fields within the semiclassical dipole approximation, WavePacket can be used to simulate experiments involving tailored light pulses in photo-induced physics or chemistry. The graphical capabilities allow visualization of quantum dynamics ‘on the fly’, including Wigner phase space representations. Being easy to use and highly versatile, WavePacket is well suited for the teaching of quantum mechanics as well as for research projects in atomic, molecular and optical physics or in physical or theoretical chemistry. The present Part I deals with the description of closed quantum systems in terms of Schrödinger equations. The emphasis is on discrete variable representations for spatial discretization as well as various techniques for temporal discretization. The upcoming Part II will focus on open quantum systems and dimension reduction; it also describes the codes for optimal control of quantum dynamics. The present work introduces the MATLAB version of WavePacket 5.2.1 which is hosted at the Sourceforge platform, where extensive Wiki-documentation as well as worked-out demonstration examples can be found. KW - Schrodinger equation KW - Quantum dynamics KW - Numerical propagation KW - Bound states KW - Discrete variable representation KW - Non-adiabatic transitions Y1 - 0207 U6 - https://doi.org/10.1016/j.cpc.2016.12.007 SN - 0010-4655 SN - 1879-2944 VL - 213 SP - 223 EP - 234 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Strauch, Peter A1 - Kossmann, Alexander A1 - Kelling, Alexandra A1 - Schilde, Uwe T1 - EPR on bis(1,2-dithiosquarato)cuprate(II) in the bis(1,2-dithiosquarato)nickelate(II) host lattice - structure and spectroscopy JF - Chemical papers N2 - EPR spectroscopy is a well suited analytical tool to monitor the electronic situation around paramagnetic metal centres as copper(II) and therefore the structural influences on the paramagnetic ion. 1,2-Dithiosquaratometalates are available by direct synthesis from metal salts with dipotassium-1,2-dithiosquarate and the appropriate counter cations. Synthesis and characterisation of bis(benzyltributylammonium)1,2-dithiosquaratonickelate(II), (BzlBu(3)N)(2)[Ni(dtsq)(2)], and bis(benzyltributylammonium)1,2-dithiosquaratocuprate(II), (BzlBu(3)N)(2)[Cu(dtsq)(2)], with benzyltributylammonium as the counter ion is reported and the X-ray structures of two complexes, (BzlBu(3)N)(2)[Ni(dtsq)(2)] and (BzlBu(3)N)(2)[Cu(dtsq)(2)], are presented. Both complexes, crystallising in the monoclinic space group P2(1)/c, are isostructural with only small differences in the coordination sphere due to the different metal ions. The diamagnetic nickel complex is therefore well suited as a host lattice for the paramagnetic Cu(II) complex to measure EPR for additional structural information. (c) 2015 Institute of Chemistry, Slovak Academy of Sciences KW - 1,2-dithiosquarate KW - 1,2-dithiosquaratometalate KW - X-ray structure KW - EPR spectroscopy Y1 - 2016 U6 - https://doi.org/10.1515/chempap-2015-0154 SN - 0366-6352 SN - 1336-9075 VL - 70 SP - 61 EP - 68 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Schmidt, Bernd A1 - Riemer, Martin T1 - Synthesis of Allyl- and Prenylcoumarins via Microwave-Promoted Tandem Claisen Rearrangement/Wittig Olefination JF - Synthesis N2 - Allyl, dimethylallyl, crotyl, and prenyl ethers of various aromatic ortho-hydroxy carbonyl compounds undergo a tandem sequence of Claisen rearrangement, carbonyl olefination, and cyclization upon microwave irradiation in the presence of a stabilized ylide. The products are multiply substituted 6- or 8-allylated or prenylated coumarins (2H-chromen-2-ones). KW - aldehydes KW - coumarins KW - ketones KW - microwave irradiation KW - olefination KW - tandem reaction KW - ylides Y1 - 2016 U6 - https://doi.org/10.1055/s-0035-1560501 SN - 0039-7881 SN - 1437-210X VL - 48 SP - 141 EP - 149 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Braune, Steffen A1 - Gross, M. A1 - Walter, M. A1 - Zhou, Shengqiang A1 - Dietze, Siegfried A1 - Rutschow, S. A1 - Lendlein, Andreas A1 - Tschoepe, C. A1 - Jung, Friedrich T1 - Adhesion and activation of platelets from subjects with coronary artery disease and apparently healthy individuals on biomaterials JF - Journal of biomedical materials research : an official journal of the Society for Biomaterials, the Japanese Society for Biomaterials; the Australian Society for Biomaterials N2 - On the basis of the clinical studies in patients with coronary artery disease (CAD) presenting an increased percentage of activated platelets, we hypothesized that hemocompatibility testing utilizing platelets from healthy individuals may result in an underestimation of the materials' thrombogenicity. Therefore, we investigated the interaction of polymer-based biomaterials with platelets from CAD patients in comparison to platelets from apparently healthy individuals. In vitro static thrombogenicity tests revealed that adherent platelet densities and total platelet covered areas were significantly increased for the low (polydimethylsiloxane, PDMS) and medium (Collagen) thrombogenic surfaces in the CAD group compared to the healthy subjects group. The area per single platelet—indicating the spreading and activation of the platelets—was markedly increased on PDMS treated with PRP from CAD subjects. This could not be observed for collagen or polytetrafluoroethylene (PTFE). For the latter material, platelet adhesion and surface coverage did not differ between the two groups. Irrespective of the substrate, the variability of these parameters was increased for CAD patients compared to healthy subjects. This indicates a higher reactivity of platelets from CAD patients compared to the healthy individuals. Our results revealed, for the first time, that utilizing platelets from apparently healthy donors bears the risk of underestimating the thrombogenicity of polymer-based biomaterials. KW - platelets KW - biomaterials KW - hemocompatibility KW - cardiovascular disease KW - cardiovascular implant Y1 - 2016 U6 - https://doi.org/10.1002/jbm.b.33366 SN - 1552-4973 SN - 1552-4981 VL - 104 SP - 210 EP - 217 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Prestel, Andreas A1 - Möller, Heiko Michael T1 - Spatio-temporal control of cellular uptake achieved by photoswitchable cell-penetrating peptides JF - Chemical communications N2 - The selective uptake of compounds into specific cells of interest is a major objective in cell biology and drug delivery. By incorporation of a novel, thermostable azobenzene moiety we generated peptides that can be switched optically between an inactive state and an active, cell-penetrating state with excellent spatio-temporal control. Y1 - 2016 U6 - https://doi.org/10.1039/c5cc06848g SN - 1359-7345 SN - 1364-548X VL - 52 SP - 701 EP - 704 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Brietzke, Thomas Martin A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Mickler, Wulfhard A1 - Holdt, Hans-Jürgen T1 - Heterodinuclear Ruthenium(II) Complexes of the Bridging Ligand 1,6,7,12-Tetraazaperylene with Iron(II), Cobalt(II), Nickel(II), as well as Palladium(II) and Platinum(II) JF - Zeitschrift für anorganische und allgemeine Chemie N2 - The first heterodinuclear ruthenium(II) complexes of the 1,6,7,12-tetraazaperylene (tape) bridging ligand with iron(II), cobalt(II), and nickel(II) were synthesized and characterized. The metal coordination sphere in this complexes is filled by the tetradentate N,N-dimethyl-2,11-diaza[3.3](2,6)-pyridinophane (L-N4Me2) ligand, yielding complexes of the general formula [(L-N4Me2)Ru(mu-tape)M(L-N4Me2)](ClO4)(2)(PF6)(2) with M = Fe {[2](ClO4)(2)(PF6)(2)}, Co {[3](ClO4)(2)(PF6)(2)}, and Ni {[4](ClO4)(2)(PF6)(2)}. Furthermore, the heterodinuclear tape ruthenium(II) complexes with palladium(II)- and platinum(II)-dichloride [(bpy)(2)Ru(-tape)PdCl2](PF6)(2) {[5](PF6)(2)} and [(dmbpy)(2)Ru(-tape)PtCl2](PF6)(2) {[6](PF6)(2)}, respectively were also prepared. The molecular structures of the complex cations [2](4+) and [4](4+) were discussed on the basis of the X-ray structures of [2](ClO4)(4)MeCN and [4](ClO4)(4)MeCN. The electrochemical behavior and the UV/Vis absorption spectra of the heterodinuclear tape ruthenium(II) complexes were explored and compared with the data of the analogous mono- and homodinuclear ruthenium(II) complexes of the tape bridging ligand. KW - N ligands KW - Ruthenium KW - Structure elucidation KW - Charge transfer KW - Electrochemistry Y1 - 2016 U6 - https://doi.org/10.1002/zaac.201500645 SN - 0044-2313 SN - 1521-3749 VL - 642 SP - 8 EP - 13 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Hildebrand, Viet A1 - Laschewsky, Andre A1 - Wischerhoff, Erik T1 - Modulating the solubility of zwitterionic poly((3methacrylamidopropyl)ammonioalkane sulfonate)s in water and aqueous salt solutions via the spacer group separating the cationic and the anionic moieties JF - Polymer Chemistry N2 - Complementary to the well-established zwitterionic monomer 3-((3-methacrylamidopropyl) dimethylammonio) propane-1-sulfonate (SPP), the closely related monomers 2-hydroxy-3-((3-methacrylamidopropyl) dimethylammonio) propane-1-sulfonate (SHPP) and 4-((3-methacrylamidopropyl) dimethylammonio)butane- 1-sulfonate (SBP) were synthesised and polymerised by reversible addition-fragmentation chain transfer (RAFT) polymerisation, using a fluorophore labeled RAFT agent. The polyzwitterions of systematically varied molar masses were characterised with respect to their solubility in water and aqueous salt solutions. Both poly(sulfobetaine)s show thermoresponsive behaviour in water, exhibiting phase separation at low temperatures and upper critical solution temperatures (UCST). For both polySHPP and polySBP, cloud points depend notably on the molar mass, and are much higher in D2O than in H2O. Also, the cloud points are effectively modulated by the addition of salts. The individual effects can be in parts correlated to the Hofmeister series for the anions studied. Still, they depend in a complex way on the concentration and the nature of the added electrolytes, on the one hand, and on the detailed nature of the spacer group separating the anionic and the cationic charges of the betaine moiety, on the other hand. As anticipated, the cloud points of polySBP are much higher than the ones of the analogous polySPP of identical molar mass. Surprisingly, the cloud points of polySHPP are also somewhat higher than the ones of their polySPP analogues, despite the additional hydrophilic hydroxyl group present in the spacer separating the ammonium and the sulfonate moieties. These findings point to a complicated interplay of the various hydrophilic components in polyzwitterions with respect to their overall hydrophilicity. Thus, the spacer group in the betaine moiety proves to be an effective additional molecular design parameter, apparently small variations of which strongly influence the phase behaviour of the polyzwitterions in specific aqueous environments. Y1 - 2016 U6 - https://doi.org/10.1039/c5py01642h SN - 1759-9954 SN - 1759-9962 VL - 7 SP - 731 EP - 740 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Thielke, Michael W. A1 - Secker, Christian A1 - Schlaad, Helmut A1 - Theato, Patrick T1 - Electrospinning of Crystallizable Polypeptoid Fibers JF - Macromolecular rapid communications N2 - A unique fabrication process of low molar mass, crystalline polypeptoid fibers is described. Thermoresponsive fiber mats are prepared by electrospinning a homogeneous blend of semicrystalline poly(N-(n-propyl) glycine) (PPGly; 4.1 kDa) with high molar mass poly(ethylene oxide) (PEO). Annealing of these fibers at approximate to 100 degrees C selectively removes the PEO and produces stable crystalline fiber mats of pure PPGly, which are insoluble in aqueous solution but can be redissolved in methanol or ethanol. The formation of water-stable polypeptoid fiber mats is an important step toward their utilization in biomedical applications such as tissue engineering or wound dressing. KW - biomaterials KW - crystallization KW - electrospinning KW - polypeptoids KW - thermoresponsive Y1 - 2016 U6 - https://doi.org/10.1002/marc.201500502 SN - 1022-1336 SN - 1521-3927 VL - 37 SP - 100 EP - 104 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Omorogie, Martins O. A1 - Babalola, Jonathan Oyebamiji A1 - Unuabonah, Emmanuel I. A1 - Gong, Jian R. T1 - Clean technology approach for the competitive binding of toxic metal ions onto MnO2 nano-bioextractant JF - Clean technologies and environmental policy N2 - The competitive extraction of Cr(III) onto Nauclea diderrichii seed epicarp doped with MnO2 nanoparticles (MnO2 nano-bioextractant (MNB)) in a single and binary batch system was studied. For validity of experimental data, chi square test, root mean square error, sum of the square errors, hybrid fractional error function, Marquart’s percent standard deviation and standard absolute error were used. Among the kinetic models used, pseudo-second-order and Langmuir equations gave the best fits for the experimental data, with qe (mg g) for the uptake of Cr(III) in single metal system onto MNB, then Cr(III) with Cd(II), Pb(II), Hg(II), KCl and CaCl2 in binary metal systems onto MNB were 2.611, then 1.989, 1.016, 2.208, 1.249 and 1.868 from kinetic standpoint, respectively. The initial sorption rates, h (mg/g/min), and half lives, t1/2 (min), for the uptake of Cr(III) in single metal system onto MNB, then Cr(III) with Cd(II), Pb(II), Hg(II), KCl and CaCl2 in binary metal system onto MNB were 3.497, then 2.311, 2.274, 0.242, 2.956, 45.568 and 0.747, then 5.769, 1.766, 12.144, 1.762, and 2.415, respectively. Physicochemical surface analyses such as pH of point of zero charge, Brunauer–Emmett–Teller single point and multi-point techniques for surface area analyses, scanning electron microscopy and transmission electron microscopy were done on MNB and MnO2 nanoparticles in order to understand their surface microstructures. Desorption study showed that MNB can be recycled and used for future study. Hence, MNB showed good potential to remediate Cr(III) from wastewaters and polluted water. KW - Nauclea diderrichii KW - Nano-bioextractant KW - Doping KW - Kinetics KW - Mass transfer Y1 - 2016 U6 - https://doi.org/10.1007/s10098-015-1004-z SN - 1618-954X SN - 1618-9558 VL - 18 SP - 171 EP - 184 PB - Springer CY - New York ER - TY - JOUR A1 - Megow, Jörg A1 - Kulesza, Alexander A1 - May, Volkhard T1 - A mixed quantum-classical description of pheophorbide a linear absorption spectra: Quantum-corrections of the Q(y)- and Q(x)-absorption vibrational satellites JF - Chemical physics letters N2 - The ground-state classical path approximation is utilized to compute molecular absorption spectra in a mixed quantum-classical frame. To improve the description for high-frequency vibrational satellites, related quantum correction factors are introduced. The improved method is demonstrated for the Q(y),and Q(x)-bands of pheophorbide a. (C) 2015 Elsevier B.V. All rights reserved. Y1 - 2016 U6 - https://doi.org/10.1016/j.cplett.2015.11.016 SN - 0009-2614 SN - 1873-4448 VL - 643 SP - 61 EP - 65 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Klaper, Matthias A1 - Wessig, Pablo A1 - Linker, Torsten T1 - Base catalysed decomposition of anthracene endoperoxide JF - Chemical communications N2 - Catalytic amounts of a weak base are sufficient to induce the decomposition of anthracene endoperoxides to anthraquinone. The mechanism has been elucidated by isolation of intermediates in combination with DFT calculations. The whole process is suitable for the convenient generation of hydrogen peroxide under very mild conditions. Y1 - 2016 U6 - https://doi.org/10.1039/c5cc08606j SN - 1359-7345 SN - 1364-548X VL - 52 SP - 1210 EP - 1213 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Park, H. A1 - Walta, S. A1 - Rosencrantz, Ruben R. A1 - Koerner, A. A1 - Schulte, Christoph A1 - Elling, L. A1 - Richtering, Walter A1 - Böker, Alexander T1 - Micelles from self-assembled double-hydrophilic PHEMA-glycopolymer-diblock copolymers as multivalent scaffolds for lectin binding JF - Polymer Chemistry N2 - We introduce a novel double-hydrophilic hydroxyethylmethacrylate (HEMA) based diblock glycopolymer which self-assembles into homogeneous spherical micellar structures in water. The micellar structure renders surface-oriented N-acetylglucocosamine (GlcNAc) sugar moieties for strong multivalent glycan-mediated lectin binding. Structural analysis and lectin binding is performed by microscopy methods, dynamic light scattering (DLS) and two-focus fluorescence correlation spectroscopy (2fFCS), revealing a novel micellar type of multivalent sugar binding scaffold with high potential for biomedical applications. Y1 - 2016 U6 - https://doi.org/10.1039/c5py00797f SN - 1759-9954 SN - 1759-9962 VL - 7 SP - 878 EP - 886 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Omorogie, Martins O. A1 - Babalola, Jonathan Oyebamiji A1 - Unuabonah, Emmanuel I. A1 - Song, Weiguo A1 - Gong, Jian Ru T1 - Efficient chromium abstraction from aqueous solution using a low-cost biosorbent: Nauclea diderrichii seed biomass waste JF - Journal of Saudi Chemical Society N2 - Toxic Cr(III) which poses environmental hazard to flora and fauna was efficiently abstracted by low-cost Nauclea diderrichii seed biomass (NDS) with good sequestral capacity for this metal was investigated in this study. The NDS surface analyses showed that it has a specific surface area of 5.36 m(2)/g and pHpzc of 4.90. Thermogravimetric analysis of NDS showed three consecutive weight losses from 50-200 degrees C (ca. 5%), 200-400 C (ca. 35%), >400 degrees C (ca. 10%), corresponding to external water molecules, structural water molecules and heat induced condensation reactions respectively. Differential thermogram of NDS presented a large endothermic peak between 20-510 degrees C suggesting bond breakage and dissociation with the ultimate release of small molecules. The experimental data showed kinetically fast biosorption with increased initial Cr(III) concentrations, indicating the role of external mass transfer mechanism as the rate controlling mechanism in this adsorption process. The Langmuir biosorption capacity of NDS was 483.81 mg/g. The use of the corrected Akaike Information Criterion tool for ranking equilibrium models suggested that the Freundlich model best described the experimental data, which is an indication of the heterogeneous nature of the active sites on the surface of NDS. N. diderrichii seed biomass is an easily sourced, cheap and environmental friendly biosorbent which will serve as a good and cost effective alternative to activated carbon for the treatment of polluted water and industrial effluents. (C) 2012 King Saud University. Production and hosting by Elsevier B.V. All rights reserved. KW - Biomass KW - Equilibrium KW - External mass transfer KW - Kinetics KW - Adsorption KW - Water Y1 - 2016 U6 - https://doi.org/10.1016/j.jscs.2012.09.017 SN - 1319-6103 SN - 2212-4640 VL - 20 SP - 49 EP - 57 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Baier, Heiko A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Holdt, Hans-Jürgen T1 - Investigation of the Catalytic Activity of a 2-Phenylidenepyridine Palladium(II) Complex Bearing 4,5-Dicyano-1,3-bis(mesityl)imidazol-2-ylidene in the Mizoroki-Heck Reaction JF - Zeitschrift für anorganische und allgemeine Chemie N2 - The phenylidenepyridine (ppy) palladacycles [PdCl(ppy)(IMes)] (4) [IMes = 1,3-bis(mesityl) imidazol-2-ylidene] and [PdCl(ppy){(CN)(2)IMes}] (6) [(CN)(2)IMes = 4,5-dicyano-1,3-bis(mesityl) imidazol-2-ylidene] were prepared by facile two step syntheses, starting with the reaction of palladium(II) chloride with 2-phenylpyridine followed by subsequent addition of the NHC ligand to the precatalyst precursor [PdCl(ppy)](2). Suitable crystals for the X-ray analysis of the complexes 4 and 6 were obtained. It was shown that 6 has a shorter NHC-palladium bond than the IMes complex 4. The difference of the palladium carbene bond lengths based on the higher pi-acceptor strength of (CN)(2)IMes in comparison to IMes. Thus, (CN)(2)IMes should stabilize the catalytically active central palladium atom better than IMes. As a measure for the pi-acceptor strength of (CN)(2)IMes compared to IMes, the selone (CN)(2)IMes center dot Se (7) was prepared and characterized by Se-77-NMR spectroscopy. The pi-acceptor strength of 7 was illuminated by the shift of its Se-77-NMR signal. The Se-77-NMR signal of 7 was shifted to much higher frequencies than the Se-77-NMR signal of IMes center dot Se. Catalytic experiments using the Mizoroki-Heck reaction of aryl chlorides with n-butyl acrylate showed that 6 is the superior performer in comparison to 4. Using complex 6, an extensive substrate screening of 26 different aryl bromides with n-butyl acrylate was performed. Complex 6 is a suitable precatalyst for para-substituted aryl bromides. The catalytically active species was identified by mercury poisoning experiments to be palladium nanoparticles. KW - Carbene ligands KW - Heck reaction KW - Palladium KW - Selenium KW - C-C coupling Y1 - 2016 U6 - https://doi.org/10.1002/zaac.201500625 SN - 0044-2313 SN - 1521-3749 VL - 642 SP - 140 EP - 147 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Bader, Denise A1 - Klier, Dennis Tobias A1 - Hettrich, C. A1 - Bier, Frank Fabian A1 - Wessig, Pablo T1 - Detecting carbohydrate-lectin interactions using a fluorescent probe based on DBD dyes JF - Analytical methods : advancing methods and applications N2 - Herein we present an efficient synthesis of a biomimetic probe with modular construction that can be specifically bound by the mannose binding FimH protein - a surface adhesion protein of E. coli bacteria. The synthesis combines the new and interesting DBD dye with the carbohydrate ligand mannose via a Click reaction. We demonstrate the binding to E. coli bacteria over a large concentration range and also present some special characteristics of those molecules that are of particular interest for the application as a biosensor. In particular, the mix-and-measure ability and the very good photo-stability should be highlighted here. Y1 - 2016 U6 - https://doi.org/10.1039/c5ay02991k SN - 1759-9660 SN - 1759-9679 VL - 8 SP - 1235 EP - 1238 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Balderas-Valadez, Ruth Fabiola A1 - Agarwal, Vivechana A1 - Pacholski, Claudia T1 - Fabrication of porous silicon-based optical sensors using metal-assisted chemical etching JF - RSC Advances N2 - Optical biosensors based on porous silicon were fabricated by metal assisted chemical etching. Thereby double layered porous silicon structures were obtained consisting of porous pillars with large pores on top of a porous silicon layer with smaller pores. These structures showed a similar sensing performance in comparison to electrochemically produced porous silicon interferometric sensors. Y1 - 2016 U6 - https://doi.org/10.1039/c5ra26816h SN - 2046-2069 VL - 6 SP - 21430 EP - 21434 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Prinz, Julia A1 - Heck, Christian A1 - Ellerik, Lisa A1 - Merk, Virginia A1 - Bald, Ilko T1 - DNA origami based Au-Ag-core-shell nanoparticle dimers with single-molecule SERS sensitivity JF - Nanoscale N2 - DNA origami nanostructures are a versatile tool to arrange metal nanostructures and other chemical entities with nanometer precision. In this way gold nanoparticle dimers with defined distance can be constructed, which can be exploited as novel substrates for surface enhanced Raman scattering (SERS). We have optimized the size, composition and arrangement of Au/Ag nanoparticles to create intense SERS hot spots, with Raman enhancement up to 10(10), which is sufficient to detect single molecules by Raman scattering. This is demonstrated using single dye molecules (TAMRA and Cy3) placed into the center of the nanoparticle dimers. In conjunction with the DNA origami nanostructures novel SERS substrates are created, which can in the future be applied to the SERS analysis of more complex biomolecular targets, whose position and conformation within the SERS hot spot can be precisely controlled. Y1 - 2016 U6 - https://doi.org/10.1039/c5nr08674d SN - 2040-3364 SN - 2040-3372 VL - 8 SP - 5612 EP - 5620 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Paz, Cristian A1 - Becerra, Jose A1 - Silva, Mario A1 - Cabrera-Pardo, Jaime A1 - Burgos, Viviana A1 - Heydenreich, Matthias A1 - Schmidt, Bernd T1 - (-)-8-Oxohobartine a New Indole Alkaloid from Aristotelia chilensis (Mol.) Stuntz JF - Records of Natural Products N2 - The fruit of Aristotelia chilensis is considered a "super fruit" due to its high concentration of polyphenols displaying exceptional antioxidant capacities ORAC. From maqui berries have been reported several anthocyanins and glycosylated flavonoids, those benefits increase the attention to restudy the plant. From the leaves of A. chilensis several indole alkaloids have been reported, we in addition to aristoteline, aristone, aristoquinoline and 3-fromylindole report the spectroscopic elucidation of 8-oxo-9-dehydromakomakine (1), hobartine (2) and a new alkaloid named 8-oxohobartine (3). Compound 1 to 3 did not show bactericidal activity against E. coli and S. aureus till 200 mu g. KW - Aristotelia chilensis KW - indole alkaloids KW - 8-oxohobartine Y1 - 2016 SN - 1307-6167 VL - 10 SP - 68 EP - 73 PB - ACG Publications CY - Gebze-Kocaeli ER - TY - JOUR A1 - Mondal, Suvendu Sekhar A1 - Marquardt, Dorothea A1 - Janiak, Christoph A1 - Holdt, Hans-Jürgen T1 - Use of a 4,5-dicyanoimidazolate anion based ionic liquid for the synthesis of iron and silver nanoparticles JF - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry N2 - Sixteen new ionic liquids (ILs) with tetraethylammonium, 1-butyl-3-methylimidazolium, 3-methyl-1-octylimidazolium and tetrabutylphosphonium cations paired with 2-substituted 4,5-dicyanoimidazolate anions (substituent at C2 = methyl, trifluoromethyl, pentafluoroethyl, N,N′-dimethyl amino and nitro) have been synthesized and characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of cation and anion type and structure of the resulting ILs, including several room temperature ionic liquids (RTILs), are reflected in the crystallization, melting points and thermal decomposition of the ILs. ILs exhibited large liquid and crystallization ranges and formed glasses on cooling with glass transition temperatures in the range of −22 to −71 °C. We selected one of the newly designed ILs due to its bigger size, compared to the common conventional IL anion and high electron-withdrawing nitrile group leads to an overall stabilization anion that may stabilize the metal nanoparticles. Stable and better separated iron and silver nanoparticles are obtained by the decomposition of corresponding Fe2(CO)9 and AgPF6, respectively, under N2-atmosphere in newly designed nitrile functionalized 4,5-dicyanoimidazolate anion based IL. Very small and uniform size for Fe-nanoparticles of about 1.8 ± 0.6 nm were achieved without any additional stabilizers or capping molecules. Comparatively bigger size of Ag-nanoparticles was obtained through the reduction of AgPF6 by hydrogen gas. Additionally, the AgPF6 precursor was decomposed under microwave irradiation (MWI), fabricating nut-in-shell-like, that is, core-separated-from-shell Ag-nano-structures. Y1 - 2016 U6 - https://doi.org/10.1039/c6dt00225k SN - 1477-9226 SN - 1477-9234 VL - 45 SP - 5476 EP - 5483 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Liebig, Ferenc A1 - Sarhan, Radwan Mohamed A1 - Prietzel, Claudia Christina A1 - Reinecke, Antje A1 - Koetz, Joachim T1 - "Green" gold nanotriangles: synthesis, purification by polyelectrolyte/micelle depletion flocculation and performance in surface-enhanced Raman scattering JF - RSC Advances N2 - The aim of this study was to develop a one-step synthesis of gold nanotriangles (NTs) in the presence of mixed phospholipid vesicles followed by a separation process to isolate purified NTs. Negatively charged vesicles containing AOT and phospholipids, in the absence and presence of additional reducing agents (polyampholytes, polyanions or low molecular weight compounds), were used as a template phase to form anisotropic gold nanoparticles. Upon addition of the gold chloride solution, the nucleation process is initiated and both types of particles, i.e., isotropic spherical and anisotropic gold nanotriangles, are formed simultaneously. As it was not possible to produce monodisperse nanotriangles with such a one-step procedure, the anisotropic nanoparticles needed to be separated from the spherical ones. Therefore, a new type of separation procedure using combined polyelectrolyte/micelle depletion flocculation was successfully applied. As a result of the different purification steps, a green colored aqueous dispersion was obtained containing highly purified, well-defined negatively charged flat nanocrystals with a platelet thickness of 10 nm and an edge length of about 175 nm. The NTs produce promising results in surface-enhanced Raman scattering. Y1 - 2016 U6 - https://doi.org/10.1039/c6ra04808k SN - 2046-2069 VL - 6 SP - 33561 EP - 33568 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Wessig, Pablo A1 - Behrends, Nicole A1 - Kumke, Michael Uwe A1 - Eisold, Ursula A1 - Meiling, Til A1 - Hille, Carsten T1 - Two-photon FRET pairs based on coumarin and DBD dyes JF - RSC Advances N2 - The synthesis and photophysical properties of two new FRET pairs based on coumarin as a donor and DBD dye as an acceptor are described. The introduction of a bromo atom dramatically increases the two-photon excitation (2PE) cross section providing a 2PE-FRET system, which is also suitable for 2PE-FLIM. Y1 - 2016 U6 - https://doi.org/10.1039/c6ra03983a SN - 2046-2069 VL - 6 SP - 33510 EP - 33513 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Doriti, Afroditi A1 - Brosnan, Sarah M. A1 - Weidner, Steffen M. A1 - Schlaad, Helmut T1 - Synthesis of polysarcosine from air and moisture stable N-phenoxycarbonyl-N-methylglycine assisted by tertiary amine base JF - Polymer Chemistry N2 - Polysarcosine (M-n = 3650-20 000 g mol(-1), D similar to 1.1) was synthesized from the air and moisture stable N-phenoxycarbonyl-N-methylglycine. Polymerization was achieved by in situ transformation of the urethane precursor into the corresponding N-methylglycine-N-carboxyanhydride, when in the presence of a non-nucleophilic tertiary amine base and a primary amine initiator. Y1 - 2016 U6 - https://doi.org/10.1039/c6py00221h SN - 1759-9954 SN - 1759-9962 VL - 7 SP - 3067 EP - 3070 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Braune, Steffen A1 - Froehlich, G. M. A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Effect of temperature on platelet adherence JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - BACKGROUND: Thrombogenicity is one of the main parameters tested in vitro to evaluate the hemocompatibility of artificial surfaces. While the influence of the temperature on platelet aggregation has been addressed by several studies, the temperature influence on the adherence of platelets to body foreign surfaces as an important aspect of biomedical device handling has not yet been explored. Therefore, we analyzed the influence of two typically applied incubation-temperatures (22 degrees C and 37 degrees C) on the adhesion of platelets to biomaterials. MATERIAL AND METHODS: Thrombogenicity of three different polymers - medical grade poly(dimethyl siloxane) (PDMS), polytetrafluoroethylene (PTFE) and polyethylene terephthalate (PET) - were studied in an in vitro static test. Platelet adhesion was studied with stringently characterized blood from apparently healthy subjects. Collection of whole blood and preparation of platelet rich plasma (PRP) was carried out at room temperature (22 degrees C). PRP was incubated with the polymers either at 22 degrees C or 37 degrees C. Surface adherent platelets were fixed, fluorescently labelled and assessed by an image-based approach. RESULTS AND DISCUSSION: Differences in the density of adherent platelets after incubation at 22 degrees C and 37 degrees C occurred on PDMS and PET. Similar levels of adherent platelets were observed on the very thrombogenic PTFE. The covered surface areas per single platelet were analyzed to measure the state of platelet activation and revealed no differences between the two incubation temperatures for any of the analyzed polymers. Irrespective of the observed differences between the low and medium thrombogenic PDMS and PET and the higher variability at 22 degrees C, the thrombogenicity of the three investigated polymers was evaluated being comparable at both incubation temperatures. KW - Biomaterial KW - thrombogenicity KW - platelet adhesion KW - platelet activation KW - temperature Y1 - 2016 U6 - https://doi.org/10.3233/CH-152028 SN - 1386-0291 SN - 1875-8622 VL - 61 SP - 681 EP - 688 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Kumar, Reddi K. A1 - Basu, Sayantani A1 - Lemke, Horst-Dieter A1 - Jankowski, Joachim A1 - Kratz, Karl A1 - Lendlein, Andreas A1 - Tetali, Sarada D. T1 - Effect of extracts of poly(ether imide) microparticles on cytotoxicity, ROS generation and proinflammatory effects on human monocytic (THP-1) cells JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - A high cell viability of around 99 +/- 18% and 99 +/- 5% was observed when THP-1 cells were cultured in the presence of aqueous extracts of the PEI microparticles in medium A and medium B respectively. The obtained microscopic data suggested that PEI particle extracts have no significant effect on cell death, oxidative stress or differentiation to macrophages. It was further found that the investigated proinflammatory markers in THP-1 cells were not up-regulated. These results are promising with regard to the biocompatibility of PEI microparticles and in a next step the hemocompatibility of the microparticles will be examined. KW - Chronic kidney disease (CKD) KW - cytotoxicity KW - human monocytic (THP-1) cells KW - poly(ether imide) microparticles KW - reactive oxygen species (ROS) Y1 - 2016 U6 - https://doi.org/10.3233/CH-152027 SN - 1386-0291 SN - 1875-8622 VL - 61 SP - 667 EP - 680 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Tetali, Sarada D. A1 - Jankowski, Vera A1 - Luetzow, Karola A1 - Kratz, Karl A1 - Lendlein, Andreas A1 - Jankowski, Joachim T1 - Adsorption capacity of poly(ether imide) microparticles to uremic toxins JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Uremia is a phenomenon caused by retention of uremic toxins in the plasma due to functional impairment of kidneys in the elimination of urinary waste products. Uremia is presently treated by dialysis techniques like hemofiltration, dialysis or hemodiafiltration. However, these techniques in use are more favorable towards removing hydrophilic than hydrophobic uremic toxins. Hydrophobic uremic toxins, such as hydroxy hipuric acid (OH-HPA), phenylacetic acid (PAA), indoxyl sulfate (IDS) and p-cresylsulfate (pCRS), contribute substantially to the progression of chronic kidney disease (CKD) and cardiovascular disease. Therefore, objective of the present study is to test adsorption capacity of highly porous microparticles prepared from poly(ether imide) (PEI) as an alternative technique for the removal of uremic toxins. Two types of nanoporous, spherically shaped microparticles were prepared from PEI by a spraying/coagulation process. PEI particles were packed into a preparative HPLC column to which a mixture of the four types of uremic toxins was injected and eluted with ethanol. Eluted toxins were quantified by analytical HPLC. PEI particles were able to adsorb all four toxins, with the highest affinity for PAA and pCR. IDS and OH-HPA showed a partially non-reversible binding. In summary, PEI particles are interesting candidates to be explored for future application in CKD. KW - Adsorption of uremic toxins KW - chronic kidney disease (CKD) KW - hydrophobic uremic toxins KW - poly(ether imide) KW - microparticles KW - uremia Y1 - 2016 U6 - https://doi.org/10.3233/CH-152026 SN - 1386-0291 SN - 1875-8622 VL - 61 SP - 657 EP - 665 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Olejko, Lydia A1 - Cywinski, P. J. A1 - Bald, Ilko T1 - An ion-controlled four-color fluorescent telomeric switch on DNA origami structures JF - Nanoscale N2 - The folding of single-stranded telomeric DNA into guanine (G) quadruplexes is a conformational change that plays a major role in sensing and drug targeting. The telomeric DNA can be placed on DNA origami nanostructures to make the folding process extremely selective for K+ ions even in the presence of high Na+ concentrations. Here, we demonstrate that the K+-selective G-quadruplex formation is reversible when using a cryptand to remove K+ from the G-quadruplex. We present a full characterization of the reversible switching between single-stranded telomeric DNA and G-quadruplex structures using Forster resonance energy transfer (FRET) between the dyes fluorescein (FAM) and cyanine3 (Cy3). When attached to the DNA origami platform, the G-quadruplex switch can be incorporated into more complex photonic networks, which is demonstrated for a three-color and a four-color FRET cascade from FAM over Cy3 and Cy5 to IRDye700 with G-quadruplex-Cy3 acting as a switchable transmitter. Y1 - 2016 U6 - https://doi.org/10.1039/c6nr00119j SN - 2040-3364 SN - 2040-3372 VL - 8 SP - 10339 EP - 10347 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Liu, Bing A1 - Böker, Alexander T1 - Measuring rotational diffusion of colloidal spheres with confocal microscopy JF - Soft matter N2 - We report an experimental method to measure the translational and rotational dynamics of colloidal spheres in three dimensions with confocal microscopy and show that the experimental values reasonably agree with the theoretical values. This method can be extended to study rotational dynamics in concentrated colloidal systems and complex bio-systems. Y1 - 2016 U6 - https://doi.org/10.1039/c6sm01082b SN - 1744-683X SN - 1744-6848 VL - 12 SP - 6033 EP - 6037 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kathrein, Christine C. A1 - Bai, Wubin A1 - Nunns, Adam A1 - Gwyther, Jessica A1 - Manners, Ian A1 - Böker, Alexander A1 - Tsarkova, Larisa A1 - Ross, Caroline A. T1 - Electric field manipulated nanopatterns in thin films of metalorganic 3-miktoarm star terpolymers JF - Soft matter N2 - We report the effect of electric field on the morphological transitions and ordering behavior of polyferrocenylethylmethylsilane block (PFEMS)-containing copolymers. By analyzing structures in solvent-annealed films of metalorganic sphere-and cylinder-forming diblock copolymers, as well as of 3-miktoarm polyisoprene-arm-polystyrene-arm-PFEMS (3 mu-ISF) terpolymers, we decouple two types of responses to the electric field: morphological transformations as a result of an increase in the volume fraction of the PFEMS block by oxidation of the ferrocenyl groups, and the orientation of the dielectric interfaces of microdomains parallel to the electric field vector. In the case of 3m-ISF, the former effect dominates at high electric field strengths which results in an unexpected cylinder-to-sphere transition, leading to a well-ordered hexagonal dot pattern. Our results demonstrate multiple tunability of ordered microdomain morphologies, suggesting future applications in nanofabrication and surface patterning. Y1 - 2016 U6 - https://doi.org/10.1039/c6sm00451b SN - 1744-683X SN - 1744-6848 VL - 12 SP - 4866 EP - 4874 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kathrein, Christine C. A1 - Pester, Christian A1 - Ruppel, Markus A1 - Jung, Maike A1 - Zimmermann, Marc A1 - Böker, Alexander T1 - Reorientation mechanisms of block copolymer/CdSe quantum dot composites under application of an electric field JF - Soft matter N2 - Time- and temperature-resolved in situ birefringence measurements were applied to analyze the effect of nanoparticles on the electric field-induced alignment of a microphase separated solution of poly(styrene)-block-poly(isoprene) in toluene. Through the incorporation of isoprene-confined CdSe quantum dots the reorientation behavior is altered. Particle loading lowers the order-disorder transition temperature, and increases the defect density, favoring nucleation and growth as an alignment mechanism over rotation of grains. The temperature dependent alteration in the reorientation mechanism is analyzed via a combination of birefringence and synchrotron SAXS. The detailed understanding of the effect of nanoparticles on the reorientation mechanism is an important prerequisite for optimization of electricfield-induced alignment of block copolymer/nanoparticle composites where the block copolymer guides the nanoparticle self-assembly into anisotropic structures. Y1 - 2016 U6 - https://doi.org/10.1039/c6sm01073c SN - 1744-683X SN - 1744-6848 VL - 12 SP - 8417 EP - 8424 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Baraza, Lilechi D. A1 - Neser, Wekesa A1 - Jackson, Korir Cheruiyot A1 - Fredrick, Juma B. A1 - Dennis, Ochieno A1 - Wairimu, Kamau R. A1 - Keya, Aggrey Osogo A1 - Heydenreich, Matthias T1 - Antimicrobial Coumarins from the Oyster Culinary-Medicinal Mushroom, Pleurotus ostreatus (Agaricomycetes), from Kenya JF - International journal of medicinal mushrooms N2 - Pleurotus ostreatus has been widely used as food because of its nutritional and medicinal properties. These have been attributed to the presence of macronutrients, minerals, vitamins, and amino acids, among other secondary metabolites. There are, however, few reports on the antimicrobial activities of different classes of purified compounds from P. ostreatus. This led to the current study, the objective of which was to chemically characterize the antibiotic activities of P. ()streams against selected human pathogenic bacteria and endophytic fungi. Chemical structures were determined using spectroscopic methods and by comparison with values of related structures reported in the literature. Pure compounds from P. ostreatus were tested in vitro against pathogenic bacteria (Staphylococcus aureus and Escherichia coli) and endophytic fungi (Pencillium digitatum and Fusarium prolferatum). A new compound, (E)-5,7-dimethoxy-6-(3-methylbuta-1,3-dienyl)-2H-chromen-2-one (5-methoxy-(E)-suberodiene) (compound 2), along with ergosterol (compound I.) and 5,7-dimethoxy-6-(3-methylbut-2-enyl)-2H-chromen-2-one (toddaculin; compound 3), were isolated from the fruiting bodies of P. ostreatus. The growth of S. aureus,E proliferatum, and P. digitatum colonies was inhibited in media containing compound 2, with minimum inhibitory concentrations closely comparable to those of conventional antibiotics. KW - Escherichia coli KW - Fusarium proliferatum KW - medicinal mushrooms KW - Penicillium digitatum KW - Pleurotus ostreatus KW - Staphylococcus aureus Y1 - 2016 U6 - https://doi.org/10.1615/IntJMedMushrooms.v18.i10.60 SN - 1521-9437 SN - 1940-4344 VL - 18 SP - 905 EP - 913 PB - Begell House CY - Danbury ER - TY - JOUR A1 - Cywinski, Piotr J. A1 - Pietraszkiewicz, Marek A1 - Maciejczyk, Michal A1 - Gorski, Krzysztof A1 - Hammann, Tommy A1 - Liermann, Konstanze A1 - Paulke, Bernd-Reiner A1 - Löhmannsröben, Hans-Gerd T1 - Total protein concentration quantification using nanobeads with a new highly luminescent terbium(III) complex JF - RSC Advances N2 - Total protein concentration (TPC) is a key parameter in many biochemical experiments and its quantification is often necessary for isolation, separation, and analysis of proteins. A sensitive and rapid nanobead-based TPC quantification assay based on Forster Resonance Energy Transfer (FRET) has been developed. A new, highly luminescent Tb(III) complex has been synthesised and applied as donor in this FRET assay with an organic dye (Cy5) as acceptor. FRET-induced changes in luminescence have been investigated both at donor and acceptor emission wavelength using time-resolved luminescence spectroscopy with time-gated detection. In the assay, the Tb(III) complex and fine-tuned polyglycidyl methacrylate (PGMA) nanobeads ensure that an improvement in sensitivity and background reduction is achieved. Using 40 nm large PGMA nanobeads loaded with the Tb(III) complex, it is possible to determine TPC down to 50 ng mL(-1) in just 10 minutes. Through specific assay components the sensitivity has been improved when compared to existing nanobead-based assays and to currently known commercial methods. Additionally, the assay is relatively insensitive to the presence of contaminants, such as non-ionic detergents commonly found in biological samples. Due to no need for any centrifugal steps, this mix-and-measure bioassay can easily be implemented into routine TPC quantification protocols in biochemical laboratories. Y1 - 2016 U6 - https://doi.org/10.1039/c6ra23207h SN - 2046-2069 VL - 6 SP - 115068 EP - 115073 PB - Royal Society of Chemistry CY - Cambridge ER - TY - GEN A1 - Mondal, Suvendu Sekhar A1 - Holdt, Hans-Jürgen T1 - Breaking Down Chemical Weapons by Metal-Organic Frameworks T2 - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition N2 - Seek and destroy: Filtration schemes and self-detoxifying protective fabrics based on the ZrIV-containing metal—organic frameworks (MOFs) MOF-808 and UiO-66 doped with LiOtBu have been developed that capture and hydrolytically detoxify simulants of nerve agents and mustard gas. Both MOFs function as highly catalytic elements in these applications. KW - heterogeneous catalysis KW - hydrolysis KW - metalorganic frameworks KW - nerve agents KW - silk fibroin Y1 - 2016 U6 - https://doi.org/10.1002/anie.201508407 SN - 1433-7851 SN - 1521-3773 VL - 55 SP - 42 EP - 44 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Loncaric, Ivor A1 - Alducin, Maite A1 - Saalfrank, Peter A1 - Juaristi, J. I. T1 - Femtosecond-laser-driven molecular dynamics on surfaces: Photodesorption of molecular oxygen from Ag(110) JF - Physical review : B, Condensed matter and materials physics N2 - We simulate the femtosecond-laser-induced desorption dynamics of a diatomic molecule from a metal surface by including the effect of the electron and phonon excitations created by the laser pulse. Following previous models, the laser-induced surface excitation is treated through the two temperature model, while the multidimensional dynamics of the molecule is described by a classical Langevin equation, in which the friction and random forces account for the action of the heated electrons. In this work we propose the additional use of the generalized Langevin oscillator model to also include the effect of the energy exchange between the molecule and the heated surface lattice in the desorption dynamics. The model is applied to study the laser-induced desorption of O-2 from the Ag(110) surface, making use of a six-dimensional potential energy surface calculated within density functional theory. Our results reveal the importance of the phonon mediated process and show that, depending on the value of the electronic density in the surroundings of the molecule adsorption site, its inclusion can significantly enhance or reduce the desorption probabilities. Y1 - 2016 U6 - https://doi.org/10.1103/PhysRevB.93.014301 SN - 1098-0121 SN - 1550-235X VL - 93 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Senge, Mathias O. A1 - Flanagan, Keith J. A1 - Ryan, Aoife A. A1 - Ryppa, Claudia A1 - Donath, Mandy A1 - Twamley, Brendan T1 - Conformational and structural studies of meso monosubstituted metalloporphyrins-Edge-on molecular interactions of porphyrins in crystals JF - Tetrahedron N2 - A series of meso monosubstituted metalloporphyrins were synthesized to assess the structural chemistry of porphyrins with only one substituent. The structures of four nickel(II) and zinc(II) complexes with either alkyl or aryl residues indicate primarily planar macrocycles. This gives rise to a different type of pi-interactions in the crystal and the formation of dimeric, trimeric or tetrameric porphyrin units that function as building blocks for the overall crystal structure. Notably, some structures exhibit a unique edge-on packing of porphyrins, while the molecules of (5-n-butylporphyrinato)nickel(II) forms an unusual bilayer type structure where rows of two porphyrin macrocycles are separated by the alkyl residues arranged in a head-to-head fashion. This adds to the canon of intermolecular porphyrin packing arrangements and is of relevance for the preparation of ordered nanoscopic porphyrin devices. (C) 2015 Elsevier Ltd. All rights reserved. KW - Porphyrins KW - Conformational analysis KW - Tetrapyrroles KW - Crystal structure KW - Crystal packing Y1 - 2016 U6 - https://doi.org/10.1016/j.tet.2015.11.008 SN - 0040-4020 VL - 72 SP - 105 EP - 115 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Zhong, Qi A1 - Metwalli, Ezzeldin A1 - Rawolle, Monika A1 - Kaune, Gunar A1 - Bivigou Koumba, Achille Mayelle A1 - Laschewsky, Andre A1 - Papadakis, Christine M. A1 - Cubitt, Robert A1 - Wang, Jiping A1 - Müller-Buschbaum, Peter T1 - Influence of Hydrophobic Polystyrene Blocks on the Rehydration of Polystyrene-block-poly(methoxy diethylene glycol acrylate)-block-polystyrene Films Investigated by in Situ Neutron Reflectivity JF - Macromolecules : a publication of the American Chemical Society N2 - The rehydration of thermoresponsive polystyrene-block-poly(methoxy diethylene glycol acrylate)-block-polystyrene (PS-b-PMDEGA-b-PS) films forming a lamellar microphase-separated structure is investigated by in situ neutron reflectivity in a D2O vapor atmosphere. The rehydration of collapsed PS-b-PMDEGA-b-PS films is realized by a temperature change from 45 to 23 degrees C and comprises (1) condensation and absorption of D2O, (2) evaporation of D2O, and (3) reswelling of the film due to internal rearrangement. The hydrophobic PS layers hinder the absorption of condensed D2O, and a redistribution of embedded D2O between the hydrophobic PS layers and the hydrophilic PMDEGA layers is observed. In contrast, the rehydration of semiswollen PS-b-PMDEGA-b-PS films (temperature change from 35 to 23 degrees C) shows two prominent differences: A thicker D2O layer condenses on the surface, causing a more enhanced evaporation of D2O. The rehydrated films differ in film thickness and volume fraction of D2O, which is due to the different thermal protocols, although the final temperature is identical. Y1 - 2016 U6 - https://doi.org/10.1021/acs.macromol.5b02279 SN - 0024-9297 SN - 1520-5835 VL - 49 SP - 317 EP - 326 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schwarze, Thomas A1 - Schneider, Radu A1 - Riemer, Janine A1 - Holdt, Hans-Jürgen T1 - A Highly K+-Selective Fluorescent Probe - Tuning the K+-Complex Stability and the K+/Na+ Selectivity by Varying the Lariat-Alkoxy Unit of a Phenylaza[18]crown-6 Ionophore JF - Chemistry : an Asian journal ; an ACES journal N2 - A desirable goal is to synthesize easily accessible and highly K+/Na+-selective fluoroionophores to monitor physiological K+ levels in vitro and in vivo. Therefore, highly K+/Na+-selective ionophores have to be developed. Herein, we obtained in a sequence of only four synthetic steps a set of K+-responsive fluorescent probes 4, 5 and 6. In a systematic study, we investigated the influence of the alkoxy substitution in ortho position of the aniline moiety in -conjugated aniline-1,2,3-triazole-coumarin-fluoroionophores 4, 5 and 6 [R=MeO (4), EtO (5) and iPrO (6)] towards the K+-complex stability and K+/Na+ selectivity. The highest K+-complex stability showed fluoroionophore 4 with a dissociation constant K-d of 19mm, but the K-d value increases to 31mm in combined K+/Na+ solutions, indicating a poor K+/Na+ selectivity. By contrast, 6 showed even in the presence of competitive Na+ ions equal K-d values (K-d(K+)=45mm and K-d(K+/Na+)=45mm) and equal K+-induced fluorescence enhancement factors (FEFs=2.3). Thus, the fluorescent probe 6 showed an outstanding K+/Na+ selectivity and is a suitable fluorescent tool to measure physiological K+ levels in the range of 10-80mm in vitro. Further, the isopropoxy-substituted N-phenylaza[18]crown-6 ionophore in 6 is a highly K+-selective building block with a feasible synthetic route. KW - crown compounds KW - fluorescence KW - fluorescent probes KW - potassium KW - sodium Y1 - 2016 U6 - https://doi.org/10.1002/asia.201500956 SN - 1861-4728 SN - 1861-471X VL - 11 SP - 241 EP - 247 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Maier, Stefan K. A1 - Poluektov, Georgiy A1 - Jester, Stefan-S. A1 - Möller, Heiko Michael A1 - Hoeger, Sigurd T1 - Fast Oxidative Cyclooligomerization towards Low- and High-Symmetry Thiophene Macrocycles JF - Chemistry - a European journal N2 - Macrocycles with quaterthiophene subunits were obtained by cyclooligomerization by direct oxidative coupling of unsubstituted dithiophene moieties. The rings were closed with high selectivity by an α,β′-connection of the thiophenes as proven by NMR spectroscopy. The reaction of the precursor with terthiophene moieties yielded the symmetric α,α′-linked macrocycle in low yield together with various differently connected isomers. Blocking of the β-position of the half-rings yielded selectively the α,α′-linked macrocycle. Selected cyclothiophenes were investigated by scanning tunneling microscopy, which displayed the formation of highly ordered 2D crystalline monolayers. KW - cyclooligomers KW - scanning tunneling microscopy KW - self-assembled monolayers KW - shape-persistent macrocycles KW - thiophenes Y1 - 2016 U6 - https://doi.org/10.1002/chem.201503211 SN - 0947-6539 SN - 1521-3765 VL - 22 SP - 1379 EP - 1384 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schönborn, Jan Boyke A1 - Saalfrank, Peter A1 - Klamroth, Tillmann T1 - Controlling the high frequency response of H-2 by ultra-short tailored laser pulses: A time-dependent configuration interaction study JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - We combine the stochastic pulse optimization (SPO) scheme with the time-dependent configuration interaction singles method in order to control the high frequency response of a simple molecular model system to a tailored femtosecond laser pulse. For this purpose, we use H-2 treated in the fixed nuclei approximation. The SPO scheme, as similar genetic algorithms, is especially suited to control highly non-linear processes, which we consider here in the context of high harmonic generation. Here, we will demonstrate that SPO can be used to realize a "non-harmonic" response of H2 to a laser pulse. Specifically, we will show how adding low intensity side frequencies to the dominant carrier frequency of the laser pulse and stochastically optimizing their contribution can create a high-frequency spectral signal of significant intensity, not harmonic to the carrier frequency. At the same time, it is possible to suppress the harmonic signals in the same spectral region, although the carrier frequency is kept dominant during the optimization. (C) 2016 AIP Publishing LLC. Y1 - 2016 U6 - https://doi.org/10.1063/1.4940316 SN - 0021-9606 SN - 1089-7690 VL - 144 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Rumschöttel, Jens A1 - Kosmella, Sabine A1 - Prietzel, Claudia Christina A1 - Appelhans, Dietmar A1 - Koetz, Joachim T1 - Change in size, morphology and stability of DNA polyplexes with hyperbranched poly(ethyleneimines) containing bulky maltose units JF - Colloids and surfaces : an international journal devoted to fundamental and applied research on colloid and interfacial phenomena in relation to systems of biological origin ; B, Biointerfaces N2 - Polyplexes between Salmon DNA and non-modified hyperbranched poly(ethyleneimines) of varying molar mass, i.e., PEI(5 k) with 5000 g/mol and PEI(25 k) with 25,000 g/mol, and modified PEI(5 k) with maltose units (PEI-Mal) were investigated in dependence on the molar N/P ratio by using dynamic light scattering (DLS), zeta potential measurements, micro differential scanning calorimetry (mu-DSC), scanning-transmission electron microscopy (STEM), and cryo-scanning electron microscopy (cryo-SEM). A reloading of the polyplexes can be observed by adding the unmodified PEI samples of different molar mass. In excess of PEI a morphological transition from core-shell particles (at N/P 8) to loosely packed onion-like polyplexes (at N/P 40) is observed. The shift of the DSC melting peak from 88 degrees C to 76 degrees C indicates a destabilization of the DNA double helix due to the complexation with the unmodified PEI. Experiments with the maltose-modified PEI show a reloading already at a lower N/P ratio. Due to the presence of the sugar units in the periphery of the polycation electrostatic interactions between DNA become weaker, but cooperative H-bonding forces are reinforced. The resulting less-toxic, more compact polyplexes in excess of the PEI-Mal with two melting points and well distributed DNA segments are of special interest for extended gene delivery experiments. (C) 2015 Elsevier B.V. All rights reserved. KW - DNA complexation KW - Polyplexes KW - Maltose-modified poly(ethyleneimine) KW - Morphology Y1 - 2016 U6 - https://doi.org/10.1016/j.colsurfb.2015.11.061 SN - 0927-7765 SN - 1873-4367 VL - 138 SP - 78 EP - 85 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Knight, Joseph W. A1 - Wang, Xiaopeng A1 - Gallandi, Lukas A1 - Dolgounitcheva, Olga A1 - Ren, Xinguo A1 - Ortiz, J. Vincent A1 - Rinke, Patrick A1 - Körzdörfer, Thomas A1 - Marom, Noa T1 - Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules III: A Benchmark of GW Methods JF - Journal of chemical theory and computation N2 - The performance of different GW methods is assessed for a set of 24 organic acceptors. Errors are evaluated with respect to coupled cluster singles, doubles, and perturbative triples [CCSD(T)] reference data for the vertical ionization potentials (IPs) and electron affinities (EAs), extrapolated to the complete basis set limit. Additional comparisons are made to experimental data, where available. We consider fully self-consistent GW (scGW), partial self-consistency in the Green’s function (scGW0), non-self-consistent G0W0 based on several mean-field starting points, and a “beyond GW” second-order screened exchange (SOSEX) correction to G0W0. We also describe the implementation of the self-consistent Coulomb hole with screened exchange method (COHSEX), which serves as one of the mean-field starting points. The best performers overall are G0W0+SOSEX and G0W0 based on an IP-tuned long-range corrected hybrid functional with the former being more accurate for EAs and the latter for IPs. Both provide a balanced treatment of localized vs delocalized states and valence spectra in good agreement with photoemission spectroscopy (PES) experiments. Y1 - 2016 U6 - https://doi.org/10.1021/acs.jctc.5b00871 SN - 1549-9618 SN - 1549-9626 VL - 12 SP - 615 EP - 626 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Gallandi, Lukas A1 - Marom, Noa A1 - Rinke, Patrick A1 - Körzdörfer, Thomas T1 - Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules II: Non-Empirically Tuned Long-Range Corrected Hybrid Functionals JF - Journal of chemical theory and computation N2 - The performance of non-empirically tuned long-range corrected hybrid functionals for the prediction of vertical ionization potentials (IPs) and electron affinities (EAs) is assessed for a set of 24 organic acceptor molecules. Basis set extrapolated coupled cluster singles, doubles, and perturbative triples [CCSD(T)] calculations serve as a reference for this study. Compared to standard exchange-correlation functionals, tuned long-range corrected hybrid functionals produce highly reliable results for vertical IPs and EAs, yielding mean absolute errors on par with computationally more demanding GW calculations. In particular, it is demonstrated that long-range corrected hybrid functionals serve as ideal starting points for non-self-consistent GW calculations. Y1 - 2016 U6 - https://doi.org/10.1021/acs.jctc.5b00873 SN - 1549-9618 SN - 1549-9626 VL - 12 SP - 605 EP - 614 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Wessig, Pablo A1 - Gerngross, Maik A1 - Freyse, Daniel A1 - Bruhn, P. A1 - Przezdziak, Marc A1 - Schilde, Uwe A1 - Kelling, Alexandra T1 - Molecular Rods Based on Oligo-spiro-thioketals JF - The journal of organic chemistry N2 - We report on an extension of the previously established concept of oligospiroketal (OSK) rods by replacing a part or all ketal moieties by thioketals leading to oligospirothioketal (OSTK) rods. In this way, some crucial problems arising from the reversible formation of ketals are circumvented. Furthermore, the stability of the rods toward hydrolysis is considerably improved. To successfully implement this concept, we first developed a number of new oligothiol building blocks and improved the synthetic accessibility of known oligothiols, respectively. Another advantage of thioacetals is that terephthalaldehyde (TAA) sleeves, which are too flexible in the case of acetals can be used in OSTK rods. The viability of the OSTK approach was demonstrated by the successful preparation of some OSTK rods with a length of some nanometers. Y1 - 2016 U6 - https://doi.org/10.1021/acs.joc.5b02670 SN - 0022-3263 VL - 81 SP - 1125 EP - 1136 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Secker, Christian A1 - Voelkel, Antje A1 - Tiersch, Brigitte A1 - Koetz, Joachim A1 - Schlaad, Helmut T1 - Thermo-Induced Aggregation and Crystallization of Block Copolypeptoids in Water JF - Macromolecules : a publication of the American Chemical Society N2 - Block copolypeptoids comprising a thermosensitive, crystallizable poly(N-(n-propyl)glycine) block and a watersoluble poly(N-methylglycine) block, P70My (y = 23, 42, 76, 153, and 290), were synthesized bY ring-opening polymerization of the corresponding N-alkylglycine N-carboxyanhydrides (NCAs) and examined according to their thermo-induced aggregation and crystallization in water by turbidimetty, micro-differential scanning calorimetry (micro-DSC); cryogenic scanning electron microscopy (cryo-SEM), analytical ultracentrifugation (AUC), and static light scattering (SLS). At a temperature above the cloud point temperature, the initially formed micellar aggregates started to crystallize and grow into larger complex assemblies of about 100-500 nm, exhibiting flower-like (P70M23), ellipsoidal (P70M42 and P70M72) or irregular shapes (P70M153 and.P70M290). Y1 - 2016 U6 - https://doi.org/10.1021/acs.macromol.5b02481 SN - 0024-9297 SN - 1520-5835 VL - 49 SP - 979 EP - 985 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schürmann, Robin Mathis A1 - Bald, Ilko T1 - Decomposition of DNA Nucleobases by Laser Irradiation of Gold Nanoparticles Monitored by Surface-Enhanced Raman Scattering JF - The journal of physical chemistry : C, Nanomaterials and interfaces N2 - Different approaches have been proposed to treat cancer cells using gold nanoparticles (AuNPs) in combination with radiation ranging from infrared lasers to high-energy ion beams. Here we study the decomposition of the DNA/RNA nucleobases thymine (T) and uracil (U) and the well-known radiosensitizer 5-bromouracil (BrU) in close vicinity to AuNPs, which are irradiated with a nanosecond pulsed laser (532 nm) matching the surface plasmon resonance of the AuNPs. The induced damage of nucleobases is analyzed by UV-vis absorption spectroscopy and surface-enhanced Raman scattering (SERS). A clear DNA damage is observed upon laser irradiation. SERS spectra indicate the fragmentation of the aromatic ring system of T and U as the dominant form of damage, whereas with BrU mainly the cleavage of the Br-C bond and formation of Br- ions is observed. This is accompanied by a partial transformation of BrU into U. The observed damage is at least partly ascribed to the intermediate formation of low energy electrons from the laser-excited AuNPs and subsequent dissociative electron attachment to T, U, and BrU. These reactions represent basic DNA damage pathways occurring on the one hand in plasmon-assisted cancer therapy and on the other hand in conventional cancer radiation therapy using AuNPs as sensitizing agents. Y1 - 2016 U6 - https://doi.org/10.1021/acs.jpcc.5b10564 SN - 1932-7447 VL - 120 SP - 3001 EP - 3009 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Dietrich, Paul M. A1 - Glamsch, Stephan A1 - Ehlert, Christopher A1 - Lippitz, Andreas A1 - Kulak, Nora A1 - Unger, Wolfgang E. S. T1 - Synchrotron-radiation XPS analysis of ultra-thin silane films: Specifying the organic silicon JF - Applied surface science : a journal devoted to applied physics and chemistry of surfaces and interfaces N2 - The analysis of chemical and elemental in-depth variations in ultra-thin organic layers with thicknesses below 5 nm is very challenging. Energy- and angle-resolved XPS (ER/AR-XPS) opens up the possibility for non-destructive chemical ultra-shallow depth profiling of the outermost surface layer of ultra-thin organic films due to its exceptional surface sensitivity. For common organic materials a reliable chemical in-depth analysis with a lower limit of the XPS information depth z(95) of about 1 nm can be performed. As a proof-of-principle example with relevance for industrial applications the ER/AR-XPS analysis of different organic monolayers made of amino- or benzamidosilane molecules on silicon oxide surfaces is presented. It is demonstrated how to use the Si 2p core-level region to non-destructively depth-profile the organic (silane monolayer) - inorganic (SiO2/Si) interface and how to quantify Si species, ranging from elemental silicon over native silicon oxide to the silane itself. The main advantage of the applied ER/AR-XPS method is the improved specification of organic from inorganic silicon components in Si 2p core-level spectra with exceptional low uncertainties compared to conventional laboratory XPS. (C) 2015 Elsevier B.V. All rights reserved. KW - Synchrotron radiation XPS KW - Depth profiling KW - Silanes KW - Monolayer KW - Amines KW - Amides Y1 - 2016 U6 - https://doi.org/10.1016/j.apsusc.2015.12.052 SN - 0169-4332 SN - 1873-5584 VL - 363 SP - 406 EP - 411 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Matkovic, Aleksandar A1 - Vasic, Borislav A1 - Pesic, Jelena A1 - Prinz, Julia A1 - Bald, Ilko A1 - Milosavljevic, Aleksandar R. A1 - Gajic, Rados T1 - Enhanced structural stability of DNA origami nanostructures by graphene encapsulation JF - NEW JOURNAL OF PHYSICS N2 - We demonstrate that a single-layer graphene replicates the shape of DNA origami nanostructures very well. It can be employed as a protective layer for the enhancement of structural stability of DNA origami nanostructures. Using the AFM based manipulation, we show that the normal force required to damage graphene encapsulated DNA origami nanostructures is over an order of magnitude greater than for the unprotected ones. In addition, we show that graphene encapsulation offers protection to the DNA origami nanostructures against prolonged exposure to deionized water, and multiple immersions. Through these results we demonstrate that graphene encapsulated DNA origami nanostructures are strong enough to sustain various solution phase processing, lithography and transfer steps, thus extending the limits of DNA-mediated bottom-up fabrication. KW - graphene KW - DNA origami nanostructures KW - atomic force microscopy Y1 - 2016 U6 - https://doi.org/10.1088/1367-2630/18/2/025016 SN - 1367-2630 VL - 18 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Gangloff, Niklas A1 - Ulbricht, Juliane A1 - Lorson, Thomas A1 - Schlaad, Helmut A1 - Luxenhofer, Robert T1 - Peptoids and Polypeptoids at the Frontier of Supra- and Macromolecular Engineering JF - Chemical reviews Y1 - 2016 U6 - https://doi.org/10.1021/acs.chemrev.5b00201 SN - 0009-2665 SN - 1520-6890 VL - 116 SP - 1753 EP - 1802 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Kyriakos, Konstantinos A1 - Philipp, Martine A1 - Lin, Che-Hung A1 - Dyakonova, Margarita A1 - Vishnevetskaya, Natalya A1 - Grillo, Isabelle A1 - Zaccone, Alessio A1 - Miasnikova, Anna A1 - Laschewsky, Andre A1 - Müller-Buschbaum, Peter A1 - Papadakis, Christine M. T1 - Quantifying the Interactions in the Aggregation of Thermoresponsive Polymers: The Effect of Cononsolvency JF - Macromolecular rapid communications N2 - The aggregation kinetics of thermoresponsive core-shell micelles with a poly(N-isopropyl acrylamide) shell in pure water or in mixtures of water with the cosolvents methanol or ethanol at mole fractions of 5% is investigated during a temperature jump across the respective cloud point. Characteristically, these mixtures give rise to cononsolvency behavior. At the cloud point, aggregates are formed, and their growth is followed with time-resolved small-angle neutron scattering. Using the reversible association model, the interaction potential between the aggregates is determined from their growth rate in dependence on the cosolvents. The effect of the cosolvent is attributed to the interaction potential on the structured layer of hydration water around the aggregates. It is surmised that the latter is perturbed by the cosolvent and thus the residual repulsive hydration force between the aggregates is reduced. The larger the molar volume of the cosolvent, the more pronounced is the effect. This framework provides a molecular-level understanding of solvent-mediated effective interactions in polymer solutions and new opportunities for the rational control of self-assembly in complex soft matter systems. KW - colloidal aggregation KW - cononsolvency KW - interaction potential KW - polymer solutions KW - self-assembled micelles KW - thermoresponsive polymers Y1 - 2016 U6 - https://doi.org/10.1002/marc.201500583 SN - 1022-1336 SN - 1521-3927 VL - 37 SP - 420 EP - 425 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Pinyou, Piyanut A1 - Ruff, Adrian A1 - Poeller, Sascha A1 - Barwe, Stefan A1 - Nebel, Michaela A1 - Alburquerque, Natalia Guerrero A1 - Wischerhoff, Erik A1 - Laschewsky, Andre A1 - Schmaderer, Sebastian A1 - Szeponik, Jan A1 - Plumere, Nicolas A1 - Schuhmann, Wolfgang T1 - Thermoresponsive amperometric glucose biosensor JF - Biointerphases N2 - The authors report on the fabrication of a thermoresponsive biosensor for the amperometric detection of glucose. Screen printed electrodes with heatable gold working electrodes were modified by a thermoresponsive statistical copolymer [polymer I: poly(omega-ethoxytriethylenglycol methacrylate-omega-3-(N,N-dimethyl-N-2-methacryloyloxyethyl ammonio) propanesulfonate-co-omega-butoxydiethylenglycol methacrylate-co-2-(4-benzoyl-phenoxy)ethyl methacrylate)] with a lower critical solution temperature of around 28 degrees C in aqueous solution via electrochemically induced codeposition with a pH-responsive redox-polymer [polymer II: poly(glycidyl methacrylate-co-allyl methacrylate-co-poly(ethylene glycol) methacrylate-co-butyl acrylate-co-2-(dimethylamino) ethyl methacrylate)-[Os(bpy)(2)(4-(((2-(2-(2-aminoethoxy) ethoxy) ethyl) amino) methyl)-N,N-dimethylpicolinamide)](2+)] and pyrroloquinoline quinone-soluble glucose dehydrogenase acting as biological recognition element. Polymer II bears covalently bound Os-complexes that act as redox mediators for shuttling electrons between the enzyme and the electrode surface. Polymer I acts as a temperature triggered immobilization matrix. Probing the catalytic current as a function of the working electrode temperature shows that the activity of the biosensor is dramatically reduced above the phase transition temperature of polymer I. Thus, the local modulation of the temperature at the interphase between the electrode and the bioactive layer allows switching the biosensor from an on-to an off-state without heating of the surrounding analyte solution. (C) 2015 American Vacuum Society. Y1 - 2016 U6 - https://doi.org/10.1116/1.4938382 SN - 1934-8630 SN - 1559-4106 VL - 11 PB - American Institute of Physics CY - Melville ER -