TY - JOUR
A1 - Kim, Jiyong
A1 - Kim, Yohan
A1 - Park, Kyoungwon
A1 - Boeffel, Christine
A1 - Choi, Hyung-Seok
A1 - Taubert, Andreas
A1 - Wedel, Armin
T1 - Ligand Effect in 1-Octanethiol Passivation of InP/ZnSe/ZnS Quantum Dots-Evidence of Incomplete Surface Passivation during Synthesis
JF - Small : nano micro
N2 - The lack of anionic carboxylate ligands on the surface of InP/ZnSe/ZnS quantum dots (QDs), where zinc carboxylate ligands can be converted to carboxylic acid or carboxylate ligands via proton transfer by 1-octanethiol, is demonstrated. The as-synthesized QDs initially have an under-coordinated vacancy surface, which is passivated by solvent ligands such as ethanol and acetone. Upon exposure of 1-octanethiol to the QD surface, 1-octanethiol effectively induces the surface binding of anionic carboxylate ligands (derived from zinc carboxylate ligands) by proton transfer, which consequently exchanges ethanol and acetone ligands that bind on the incomplete QD surface. These systematic chemical analyses, such as thermogravimetric analysis-mass spectrometry and proton nuclear magnetic resonance spectroscopy, directly show the interplay of surface ligands, and it associates with QD light-emitting diodes (QD-LEDs). It is believed that this better understanding can lead to industrially feasible QD-LEDs.
KW - colloidal quantum dots
KW - incomplete surface passivation
KW - indium
KW - phosphide
KW - surface chemistry
KW - thiol passivation
Y1 - 2022
U6 - https://doi.org/10.1002/smll.202203093
SN - 1613-6810
SN - 1613-6829
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Deutschmann, Claudia
A1 - Roggenbuck, Dirk
A1 - Schierack, Peter
A1 - Rödiger, Stefan
T1 - Autoantibody testing by enzyme-linked immunosorbent assay-a case in which the solid phase decides on success and failure
JF - Heliyon
N2 - Background: The enzyme-linked immunosorbent assay (ELISA) is an indispensable tool for clinical diagnostics to identify or differentiate diseases such as autoimmune illnesses, but also to monitor their progression or control the efficacy of drugs. One use case of ELISA is to differentiate between different states (e.g. healthy vs. diseased). Another goal is to quantitatively assess the biomarker in question, like autoantibodies. Thus, the ELISA technology is used for the discovery and verification of new autoantibodies, too. Of key interest, however, is the development of immunoassays for the sensitive and specific detection of such biomarkers at early disease stages. Therefore, users have to deal with many parameters, such as buffer systems or antigen-autoantibody interactions, to successfully establish an ELISA. Often, fine-tuning like testing of several blocking substances is performed to yield high signal-to-noise ratios.
Methods: We developed an ELISA to detect IgA and IgG autoantibodies against chitinase-3-like protein 1 (CHI3L1), a newly identified autoantigen in inflammatory bowel disease (IBD), in the serum of control and disease groups (n = 23, respectively). Microwell plates with different surface modifications (PolySorp and MaxiSorp coating) were tested to detect reproducibility problems.
Results: We found a significant impact of the surface properties of the microwell plates. IgA antibody reactivity was significantly lower, since it was in the range of background noise, when measured on MaxiSorp coated plates (p < 0.0001). The IgG antibody reactivity did not differ on the diverse plates, but the plate surface had a significant influence on the test result (p = 0.0005).
Conclusion: With this report, we want to draw readers' attention to the properties of solid phases and their effects on the detection of autoantibodies by ELISA. We want to sensitize the reader to the fact that the choice of the wrong plate can lead to a false negative test result, which in turn has serious consequences for the discovery of autoantibodies.
KW - biochemistry
KW - coatings
KW - surface chemistry
KW - immunology
KW - proteins
KW - laboratory medicine
KW - clinical research
KW - enzyme-linked immunosorbent
KW - assay
KW - biomarker discovery
KW - reproducibility
KW - solid-phase
KW - autoantibody
Y1 - 2020
U6 - https://doi.org/10.1016/j.heliyon.2020.e03270
SN - 2405-8440
VL - 6
IS - 1
PB - Elsevier
CY - London [u.a.]
ER -
TY - JOUR
A1 - Goebel, Ronald
A1 - Hesemann, Peter
A1 - Friedrich, Alwin
A1 - Rothe, Regina
A1 - Schlaad, Helmut
A1 - Taubert, Andreas
T1 - Modular thiol-ene chemistry approach towards mesoporous silica monoliths with organically modified pore walls
JF - Chemistry - a European journal
N2 - The surface modification of mesoporous silica monoliths through thiol-ene chemistry is reported. First, mesoporous silica monoliths with vinyl, allyl, and thiol groups were synthesized through a sol-gel hydrolysis-poly-condensation reaction from tetramethyl orthosilicate (TMOS) and vinyltriethoxysilane, allyltriethoxysilane, and (3-mercaptopropyl) trimethoxysilane, respectively. By variation of the molar ratio of the comonomers TMOS and functional silane, mesoporous silica objects containing different amounts of vinyl, allyl, and thiol groups were obtained. These intermediates can subsequently be derivatized through radical photoaddition reactions either with a thiol or an olefin, depending on the initial pore wall functionality, to yield silica monoliths with different pore-wall chemistries. Nitrogen sorption, small-angle X-ray scattering, solid-state NMR spectroscopy, elemental analysis, thermogravimetric analysis, and redox titration demonstrate that the synthetic pathway influences the morphology and pore characteristics of the resulting monoliths and also plays a significant role in the efficiency of functionalization. Moreover, the different reactivity of the vinyl and allyl groups on the pore wall affects the addition reaction, and hence, the degree of the pore-wall functionalization. This report demonstrates that thiol-ene photoaddition reactions are a versatile platform for the generation of a large variety of organically modified silica monoliths with different pore surfaces.
KW - mesoporous materials
KW - photochemistry
KW - sol-gel processes
KW - surface chemistry
Y1 - 2014
U6 - https://doi.org/10.1002/chem.201403982
SN - 0947-6539
SN - 1521-3765
VL - 20
IS - 52
SP - 17579
EP - 17589
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Füchsel, Gernot
A1 - Tremblay, Jean Christophe
A1 - Klamroth, Tillmann
A1 - Saalfrank, Peter
T1 - Quantum dynamical simulations of the femtosecond-laser-induced ultrafast desorption of H2 and D2 from Ru(0001)
JF - ChemPhysChem : a European journal of chemical physics and physical chemistry
N2 - We investigate the recombinative desorption of hydrogen and deuterium from a Ru(0001) surface initiated by femtosecond laser pulses. We adopt a quantum mechanical two-state model including three molecular degrees of freedom to describe the dynamics within the desorption induced by electronic transition (DIET) limit. The energy distributions as well as the state-resolved and ensemble properties of the desorbed molecules are analyzed in detail by using the time-energy method. Our results shed light on the experimentally observed 1) large isotopic effects regarding desorption yields and translational energies and 2) the nonequal energy partitioning into internal and translational modes. In particular, it is shown that a single temperature is sufficient to characterize the energy distributions for all degrees of freedom. Further, we confirm that quantization effects play an important role in the determination of the energy partitioning.
KW - quantum dynamics
KW - laser chemistry
KW - isotope effects
KW - surface chemistry
KW - ultrafast reactions
Y1 - 2013
U6 - https://doi.org/10.1002/cphc.201200940
SN - 1439-4235
VL - 14
IS - 7
SP - 1471
EP - 1478
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Fandrich, Artur
A1 - Buller, Jens
A1 - Wischerhoff, Erik
A1 - Laschewsky, André
A1 - Lisdat, Fred
T1 - Electrochemical detection of the thermally induced phase transition of a thin stimuli-responsive polymer film
JF - ChemPhysChem : a European journal of chemical physics and physical chemistry
KW - cyclic voltammetry
KW - electrochemical impedance spectroscopy
KW - polymers
KW - surface chemistry
KW - surface plasmon resonance
Y1 - 2012
U6 - https://doi.org/10.1002/cphc.201100924
SN - 1439-4235
VL - 13
IS - 8
SP - 2020
EP - 2023
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Lange, Maik
A1 - Braune, Steffen
A1 - Luetzow, Karola
A1 - Richau, Klaus
A1 - Scharnagl, Nico
A1 - Weinhart, Marie
A1 - Neffe, Axel T.
A1 - Jung, Friedrich
A1 - Haag, Rainer
A1 - Lendlein, Andreas
T1 - Surface functionalization of poly(ether imide) membranes with linear, methylated oligoglycerols for reducing thrombogenicity
JF - Macromolecular rapid communications
N2 - Materials for biomedical applications are often chosen for their bulk properties. Other requirements such as a hemocompatible surface shall be fulfilled by suitable chemical functionalization. Here we show, that linear, side-chain methylated oligoglycerols (OGMe) are more stable to oxidation than oligo(ethylene glycol) (OEG). Poly(ether imide) (PEI) membranes functionalized with OGMes perform at least as good as, and partially better than, OEG functionalized PEI membranes in view of protein resistance as well as thrombocyte adhesion and activation. Therefore, OGMes are highly potent surface functionalizing molecules for improving the hemocompatibility of polymers.
KW - hemocompatibility
KW - poly(ethylene glycol)
KW - polyglycerol
KW - polyimides
KW - surface chemistry
Y1 - 2012
U6 - https://doi.org/10.1002/marc.201200426
SN - 1022-1336
VL - 33
IS - 17
SP - 1487
EP - 1492
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Füchsel, Gernot
A1 - Tremblay, Jean Christophe
A1 - Klamroth, Tillmann
A1 - Saalfrank, Peter
T1 - Selective excitation of molecule-surface vibrations in H2 and D2 dissociatively adsorbed on Ru(0001)
JF - Israel journal of chemistry
N2 - In this contribution we report about the selective vibrational excitation of H2 and D2 on Ru(0001) as an example for nonadiabatic coupling of an open quantum system to a dissipative environment. We investigate the possibility of achieving state-selective vibrational excitations of H2 and D2 adsorbed on a Ru(0001) surface using picosecond infrared laser pulses. The systems behavior is explored using pulses that are rationally designed and others that are optimized using a time-local variant of Optimal Control Theory. The effects of dissipation on the laser-driven dynamics are studied using the reduced-density matrix formalism. The non-adiabatic couplings between adsorbate and surface are computed perturbatively, for which our recently introduced state-resolved anharmonic rate model is used. It is shown that mode- and state-selective excitation can be achieved in the absence of dissipation when using optimized laser pulses. The inclusion of dissipation in the model reduces the state selectivity and the population transfer yield to highly excited states. In this case, mode activation is most effectively realized by a rational pulse of carefully chosen duration rather than by a locally optimized pulse.
KW - dissipative dynamics
KW - photochemistry
KW - quantum control
KW - surface chemistry
Y1 - 2012
U6 - https://doi.org/10.1002/ijch.201100097
SN - 0021-2148
VL - 52
IS - 5
SP - 438
EP - 451
PB - Wiley-VCH
CY - Weinheim
ER -