TY - JOUR A1 - Sattari, S. A1 - Beyranvand, S. A1 - Soleimani, K. A1 - Rassoli, K. A1 - Salahi, P. A1 - Donskyi, Ievgen A1 - Shams, A. A1 - Unger, Wolfgang A1 - Yari, A. A1 - Farjanikish, G. A1 - Nayebzadeh, H. A1 - Adeli, M. T1 - Boronic Acid-Functionalized Two-Dimensional MoS2 at Biointerfaces N2 - While noncovalent interactions at two-dimensional nanobiointerfaces are extensively investigated, less knowledge about covalent interactions at this interface is available. In this work, boronic acid-functionalized 2D MoS2 was synthesized and its covalent multivalent interactions with bacteria and nematodes were investigated. Polymerization of glycidol by freshly exfoliated MoS2 and condensation of 2,5-thiophenediylbisboronic acid on the produced platform resulted in boronic acid-functionalized 2D MoS2. The destructive interactions between 2D MoS2 and bacteria as well as nematodes were significantly amplified by boronic acid functional groups. Because of the high antibacterial and antinematodal activities of boronic acid-functionalized 2D MoS2, its therapeutic efficacy for diabetic wound healing was investigated. The infected diabetic wounds were completely healed 10 days after treatment with boronic acid-functionalized 2D MoS2, and a normal structure for recovered tissues including different layers of skin, collagen, and blood vessels was detected. KW - XPS KW - Boronic acid-functionalized 2D MoS2 KW - Covalent interactions KW - Bacteria KW - Nanobiointerfaces PY - 2020 DO - https://doi.org/10.1021/acs.langmuir.0c00776 VL - 36 IS - 24 SP - 6706 EP - 6715 PB - ACS American Chemical Society AN - OPUS4-51024 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beyranvand, S. A1 - Pourghobadi, Z. A1 - Sattari, S. A1 - Soleymani, K. A1 - Donskyi, Ievgen A1 - Gharabaghi, M. A1 - Unger, Wolfgang A1 - Farjanikish, G. A1 - Nayebzadeh, H. A1 - Adeli, M. T1 - Boronic acid functionalized graphene platforms for diabetic wound N2 - While noncovalent interactions between graphene derivatives and biosystems are extensively studied, less knowledge about their covalent multivalent interactions at biointerfaces is available. Due to the affinity of boronic acids towards cis-diol bearing biosystems, graphene sheets with this functionality were synthesized and their covalent interactions with the bacteria and nematode were investigated. As expected, graphene platforms with boronic acid functionality were able to wrap bacteria and destroy it in a short time. Surprisingly, body of nematodes was ruptured and their viability decreased to 30% after 24 h incubation with the functionalized graphene sheets. Because of their antibacterial and antiparasitic activities as well as their ability for wound dressing, graphene platforms with the boronic acid functionality were further investigated for diabetic wound healing. In vivo experiments showed that graphene platforms are more efficient than the commercially available drug, phenytoin, and restore both infected and non-infected diabetic wounds in ten days. Taking advantage of their straightforward synthesis, strong interactions with different biosystems as well as their ability to heal diabetic wounds, the boronic Acid functionalized graphene sheets are promising candidates for a broad range of future biomedical applications. KW - Graphene KW - Boronic acid KW - Functionalized graphene KW - XPS PY - 2020 UR - https://www.sciencedirect.com/science/article/abs/pii/S0008622319310954 DO - https://doi.org/doi.org/10.1016/j.carbon.2019.10.077 VL - 158 SP - 327 EP - 336 PB - Elsevier Ltd. AN - OPUS4-50559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Faghani, A. A1 - Gholami, M. F. A1 - Trunk, M. A1 - Müller, J. A1 - Pachfule, P. A1 - Vogl, S. A1 - Donskyi, Ievgen A1 - Li, M. A1 - Nickl, Philip A1 - Shao, J. A1 - Huang, M. R. S. A1 - Unger, Wolfgang A1 - Arenal, R. A1 - Koch, C. T. A1 - Paulus, B. A1 - Rabe, J. P. A1 - Thomas, A. A1 - Haag, R. A1 - Adeli, M. T1 - Metal-Assisted and Solvent-Mediated Synthesis of Two-Dimensional Triazine Structures on Gram Scale N2 - Covalent triazine frameworks are an emerging material class that have shown promising performance for a range of applications. In this work, we report on a metal-assisted and solvent-mediated reaction between calcium carbide and cyanuric chloride, as cheap and commercially available precursors, to synthesize two-dimensional triazine structures (2DTSs). The reaction between the solvent, dimethylformamide, and cyanuric chloride was promoted by calcium carbide and resulted in dimethylamino-s-triazine intermediates, which in turn undergo nucleophilic substitutions. This reaction was directed into two dimensions by calcium ions derived from calcium carbide and induced the formation of 2DTSs. The role of calcium ions to direct the two-dimensionality of the final structure was simulated using DFT and further proven by synthesizing molecular intermediates. The water content of the reaction medium was found to be a crucial factor that affected the structure of the products dramatically. While 2DTSs were obtained under anhydrous conditions, a mixture of graphitic material/2DTSs or only graphitic material (GM) was obtained in aqueous solutions. Due to the straightforward and gram-scale synthesis of 2DTSs, as well as their photothermal and photodynamic properties, they are promising materials for a wide range of future applications, including bacteria and virus incapacitation. KW - XPS KW - Triazine KW - 2D PY - 2020 DO - https://doi.org/10.1021/jacs.0c02399 VL - 142 IS - 30 SP - 12976 EP - 12986 PB - ACS American Chemical Society AN - OPUS4-51203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Anja A1 - Heinrich, Thomas A1 - Tougaard, S. A1 - Werner, W. S. M. A1 - Hronek, M. A1 - Kunz, Valentin A1 - Radnik, Jörg A1 - Stockmann, Jörg M. A1 - Hodoroaba, Vasile-Dan A1 - Benemann, Sigrid A1 - Nirmalananthan-Budau, Nithiya A1 - Geißler, Daniel A1 - Sparnacci, K. A1 - Unger, Wolfgang T1 - Determining the thickness and completeness of the shell of polymer core-shell nanoparticles by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and transmission scanning electron microscopy N2 - Core–shell nanoparticles (CSNPs) have become indispensable in various industrial applications. However, their real internal structure usually deviates from an ideal core–shell structure. To control how the particles perform with regard to their specific applications, characterization techniques are required that can distinguish an ideal from a nonideal morphology. In this work, we investigated poly(tetrafluoroethylene)–poly(methyl methacrylate) (PTFE–PMMA) and poly(tetrafluoroethylene)–polystyrene (PTFE–PS) polymer CSNPs with a constant core diameter (45 nm) but varying shell thicknesses (4–50 nm). As confirmed by transmission scanning electron microscopy (T-SEM), the shell completely covers the core for the PTFE–PMMA nanoparticles, while the encapsulation of the core by the shell material is incomplete for the PTFE–PS nanoparticles. X-ray photoelectron spectroscopy (XPS) was applied to determine the shell thickness of the nanoparticles. The software SESSA v2.0 was used to analyze the intensities of the elastic peaks, and the QUASES software package was employed to evaluate the shape of the inelastic background in the XPS survey spectra. For the first time, nanoparticle shell thicknesses are presented, which are exclusively based on the analysis of the XPS inelastic background. Furthermore, principal component analysis (PCA)-assisted time-of-flight secondary-ion mass spectrometry (ToF-SIMS) of the PTFE–PS nanoparticle sample set revealed a systematic variation among the samples and, thus, confirmed the incomplete encapsulation of the core by the shell material. As opposed to that, no variation is observed in the PCA score plots of the PTFE–PMMA nanoparticle sample set. Consequently, the complete coverage of the core by the shell material is proved by ToF-SIMS with a certainty that cannot be achieved by XPS and T-SEM. KW - XPS KW - T-SEM KW - ToF-SIMS KW - Core-shell nanoparticles PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-499165 DO - https://doi.org/10.1021/acs.jpcc.9b09258 VL - 123 IS - 49 SP - 29765 EP - 29775 PB - American Chemical Society CY - Washington, DC AN - OPUS4-49916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marcoulaki, E. A1 - M. López de Ipina, J. A1 - Vercauteren, S. A1 - Bouillard, J. A1 - Himly, M. A1 - Lynch, I. A1 - Witters, H. A1 - Shandilya, N. A1 - van Duuren-Stuurman, B. A1 - Kunz, Valentin A1 - Unger, Wolfgang A1 - Hodoroaba, Vasile-Dan A1 - Bard, D. A1 - Evans, G. A1 - Jensen, K. A. A1 - Pilou, M. A1 - Viitanen, A.-K. A1 - Bochon, A. A1 - Duschl, A. A1 - Geppert, M. A1 - Persson, K. A1 - Votgreave, I. A1 - Niga, P. A1 - Gini, M. A1 - Eleftheriadis, K. A1 - Scalbi, S. A1 - Caillard, B. A1 - Arevalillo, A. A1 - Frejafon, E. A1 - Aguerre-Chariol, O. A1 - Dulio, V. T1 - Blueprint for a self-sustained European Centre for service provision in safe and sustainable innovation for nanotechnology N2 - The coming years are expected to bring rapid changes in the nanotechnology regulatory landscape, with the establishment of a new framework for nano-risk governance, in silico approaches for characterisation and Risk assessment of nanomaterials, and novel procedures for the early identification and management of nanomaterial risks. In this context, Safe(r)-by-Design (SbD) emerges as a powerful preventive approach to support the development of safe and sustainable (SSbD) nanotechnology-based products and processes throughout the life cycle. This paper summarises the work undertaken to develop a blueprint for the deployment and operation of a permanent European Centre of collaborating laboratories and research organisations supporting safe Innovation in nanotechnologies. The proposed entity, referred to as “the Centre”, will establish a ‘one-stop shop’ for nanosafety-related services and a central contact point for addressing stakeholder questions about nanosafety. Its operation will rely on significant business, legal and market knowledge, as well as other tools developed and acquired through the EU-funded EC4SafeNano project and subsequent ongoing activities. The proposed blueprint adopts a demand-driven service update scheme to allow the necessary vigilance and flexibility to identify opportunities and adjust its activities and services in the rapidly evolving regulatory and nano risk governance landscape. The proposed Centre will play a major role as a conduit to transfer scientific knowledge between the Research and commercial laboratories or consultants able to provide high quality nanosafety services, and the end-users of such services (e.g., industry, SMEs, consultancy firms, and regulatory authorities). The Centre will harmonise service provision, and bring novel risk assessment and management approaches, e.g. in silico methodologies, closer to practice, notably through SbD/SSbD, and decisively support safe and sustainable innovation of industrial production in the nanotechnology industry according to the European Chemicals Strategy for Sustainability. KW - Nanotechnology KW - European Centre KW - Nano-safety KW - Nanomaterials KW - analytical service PY - 2021 DO - https://doi.org/10.1016/j.impact.2021.100337 VL - 23 SP - 100337 PB - Elsevier B.V. AN - OPUS4-52942 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinen, S. A1 - Rackow, S. A1 - Cuellar-Camacho, J. L. A1 - Donskyi, Ievgen A1 - Unger, Wolfgang A1 - Weinhart, M. T1 - Transfer of functional thermoresponsive poly(glycidyl ether) coatings for cell sheet fabrication from gold to glass surfaces N2 - Thermoresponsive polymer coatings can facilitate cell sheet fabrication under mild conditions by promoting cell adhesion and proliferation at 37 1C. At lower temperatures the detachment of confluent cell sheets is triggered without enzymatic treatment. Thus, confluent cell sheets with intact extracellular matrix for regenerative medicine or tissue engineering applications become available. Herein, we applied the previously identified structural design parameters of functional, thermoresponsive poly(glycidyl ether) brushes on gold to the more application-relevant substrate glass via the self-assembly of a corresponding block copolymer (PGE-AA) with a short surface-reactive, amine-presenting anchor block. Both, physical and covalent immobilization on glass via either multivalent ionic interactions of the anchor block with bare glass or the coupling of the anchor block to a polydopamine (PDA) adhesion layer on glass resulted in stable coatings. Atomic force microscopy revealed a high degree of roughness of covalently attached coatings on the PDA adhesion layer, while physically attached coatings on bare glass were smooth and in the brush-like regime. Cell sheets of primary human dermal fibroblasts detached reliably (86%) and within 20 ± 10 min from physically tethered PGE-AA coatings on glass when prepared under cloud point grafting conditions. The presence of the laterally inhomogeneous PDA adhesion layer, however, hindered the spontaneous temperature-triggered cell detachment from covalently grafted PGE-AA, decreasing both detachment rate and reliability. Despite being only physically attached, self-assembled monolayer brushes of PGE-AA block copolymers on glass are functional and stable thermoresponsive coatings for application in cell sheet fabrication of human fibroblasts as determined by X-ray photoelectron spectroscopy. KW - X-ray photoelectron spectroscopy KW - Thermoresponsive poly(glycidyl ether) coatings KW - Cell sheet fabrication KW - Nm film thickness PY - 2018 DO - https://doi.org/10.1039/c7tb03263c SN - 2050-750X SN - 2050-7518 VL - 6 IS - 10 SP - 1489 EP - 1500 PB - The Royal Society of Chemistry AN - OPUS4-44600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Anja A1 - Heinrich, Thomas A1 - Tougaard, S. A1 - Werner, W. S. M. A1 - Hronek, M. A1 - Kunz, Valentin A1 - Radnik, Jörg A1 - Stockmann, Jörg M. A1 - Hodoroaba, Vasile-Dan A1 - Benemann, Sigrid A1 - Nirmalananthan-Budau, Nithiya A1 - Geißler, Daniel A1 - Sparnacci, K. A1 - Unger, Wolfgang T1 - Correction to "Determining the thickness and completeness of the shell of polymer core-shell nanoparticles by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and transmission scanning electron microscopy" N2 - This is a corrigendum to the original article "Determining the thickness and completeness of the shell of polymer core-shell nanoparticles by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and transmission scanning electron microscopy" that was published in "The journal of physical chemistry C", vol. 123 (2019), no. 49 pp. 29765-29775. PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505451 DO - https://doi.org/10.1021/acs.jpcc.0c00027 SN - 1932-7447 SN - 1932-7455 VL - 124 IS - 6 SP - 3923 PB - American Chemical Society CY - Washington, DC AN - OPUS4-50545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bütefisch, S. A1 - Weimann, T. A1 - Busch, I. A1 - Danzebrink, H.-U. A1 - Gross, Thomas A1 - Unger, Wolfgang A1 - Wirth, Thomas T1 - New reference material for imaging XPS (X-ray photoelectron spectroscopy) instrument characterization N2 - Reference materials without variations in topography are essential for the characterization of imaging XPS (X-ray Photoelectron Spectroscopy) Instruments. Therefore a new fabrication process for this kind of zero-topography reference material was developed at PTB and resulted in first prototypes. The fabrication process and first measurement results will be presented in this paper. T2 - Sensor 2015 - 17th International conference on sensors and measurement technology CY - Nuremberg, Germany DA - 19.05.2015 KW - Imaging XPS KW - Reference material KW - Topography free KW - Micro technology PY - 2015 SN - 978-3-9813484-8-4 DO - https://doi.org/10.5162/sensor2015/P7.1 SP - Chapter P7, 821 EP - 825 AN - OPUS4-33837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nietzold, Carolin A1 - Dietrich, Paul A1 - Ivanov-Pankov, S. A1 - Lippitz, Andreas A1 - Gross, Thomas A1 - Weigel, W. A1 - Unger, Wolfgang T1 - Functional group quantification on epoxy surfaces by chemical derivatization (CD)-XPS N2 - In this study, epoxy-terminated silicon oxide surfaces were chemically derivatized with trifluoroacetic anhydride (TFAA) and 4-(trifluoromethyl)-benzylamine (TFMBA) and analyzed by X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy and water contact angle measurements. TFAA was used for quantitative derivatization to determine the amount of reactive epoxy groups on these surfaces. Furthermore, epoxy-terminated surfaces were derivatized with TFMBA (a model compound for biomolecules with an amino linker) yielding secondary amines because of formation of covalent C–N bonds between TFMBA and the epoxy films. Fluorine being part of TFAA and TFMBA composition was used to follow the progress of the chemical derivatization reaction. Both derivatization agents – TFAA and TFMBA – gave comparable reaction yields of ~60% on epoxy silicon surfaces, whereas on epoxy glass slides, the derivatization yields were considerably lower (30–40%).The protocol for attachment of TFMBA (model compound) on epoxy-modified surfaces was adapted to (bio)molecules with an amino linker, e.g. carbohydrates to prepare carbohydrate-functionalized biointerfaces. KW - Biomolecular interfaces KW - Epoxy-functionalized surfaces KW - CD-XPS KW - Functional group quantification KW - Contact angle measurements PY - 2014 DO - https://doi.org/10.1002/sia.5433 SN - 0142-2421 SN - 1096-9918 VL - 46 IS - 10-11 SP - 668 EP - 672 PB - Wiley CY - Chichester AN - OPUS4-31605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Stockmann, Jörg M. A1 - Senoner, Mathias A1 - Weimann, T. A1 - Bütefisch, S. A1 - Passiu, C. A1 - Spencer, N. D. A1 - Rossi, A. T1 - Introduction to lateral resolution and analysis area measurements in XPS N2 - Imaging and small-spot (small area) XPS have become increasingly important components of surface chemical analysis during the last three decades, and its use is growing. Some ambiguity in the use of terminology, understanding of concepts, and lack of appropriate reference materials leads to confusing and not always reproducible data. In this paper, it is shown that by using existing knowledge, appropriate test specimens, and standardized approaches, problems of comparability and such reproducibility issues recently observed for XPS data reported in the scientific literature can be overcome. The standardized methods of ISO 18516:2019, (i) the straight-edge, (ii) the narrow-line, and (iii) the grating method, can be used to characterize and compare the lateral resolution achieved by imaging XPS instruments and are described by reporting examples. The respective measurements are made using new test specimens. When running an XPS instrument in the small-spot (small area) mode for a quantitative analysis of a feature of interest, the question arises as to what contribution to the intensity originates from outside the analysis area. A valid measurement approach to control the intensity from outside the nominal analysis area is also described. As always, the relevant resolution depends on the specific question that needs to be addressed. The strengths and limitations of methods defining resolution are indicated. KW - Imaging XPS KW - Lateral resolution KW - Analysis area measurements KW - Small-spot XPS PY - 2020 DO - https://doi.org/10.1116/6.0000398 VL - 38 IS - 5 SP - 053206 AN - OPUS4-51394 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Swaraj, S. A1 - Dietrich, Paul M. T1 - X-ray spectromicroscopy of nanoparticulate iron oxide phases N2 - Soft x-ray spectromicroscopy techniques have seen great amount of development in the recent years, and with the development of new diffraction limited synchrotron source, many new nanoscale and mesoscale characterization opportunities of applied materials are foreseen. In this perspective, the authors present some examples that illustrate the capabilities of spectromicroscopy techniques, namely, 2D and 3D spatially resolved chemical quantification, surface and bulk sensitive measurements, and polarization dependent measurements as applied to iron oxide nanoparticulate materials of biological, geological, and other origins. KW - X-ray spectromicroscopy KW - STXM KW - Iron oxide PY - 2016 DO - https://doi.org/10.1116/1.4966654 SN - 1934-8630 SN - 1559-4106 VL - 11 IS - 4 SP - 04B402-1 EP - 04B402-6 PB - AVS: Science & Technology of Materials, Interfaces, and Processing AN - OPUS4-38274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -