TY - CONF A1 - Bresch, Harald T1 - Core-shell systems - different cases N2 - Coating, stabilization layers, functionalization of particles or simple contamination are common variants of a core-shell system. For smaller nanoparticles this is of major importance. A particle with 16 nm diameter and a usual surface layer of 2 nm will have the same volume for the core as for the shell. In this case the material of the particle doesn’t have a clear definition. It is a common case that a particle consists of four different layers: Core, shell, stabilization layer and contamination. The properties of the particles differ according to this structure. For example silver particles might have a different dissolution rate for pure particles and for particles which are grown on top of a core. Different solubility or defined other properties of materials is a common reason for producing core-shell systems. Gold cores are surrounded by silica to stabilize them or to get a defined distance between the cores. Silica might be surrounded by gold and the silica dissolved afterwards. This delivers hollow shells. Another important example for core-shell systems are quantum dots. A small core is surrounded by a different material for increasing the photoluminescence. Furthermore there a stabilization layer is needed. The smallest part of the final particles is the initial core. The photoluminescence is based on this core, but the shells contain much more material. Categorization should address this. Core-shell systems are not covered by most of the existing decision trees for grouping. They are either regarded as special case or a singular layer. This disqualifies core-shell systems for grouping within the common models. There might be a very easy way to avoid this problem and even to combine some of the different decision trees. Starting the decision tree with the solubility of the outer shell and subsequently addressing the inner layers will be a pragmatic approach to solve the problem. If there is no shell, the categorization can start with a tiered approach or with the proposed “stawman” chemical categorization. If a shell is covering the surface there is a need to check if the shell is stable. If it is stable, the particle can be categorized based on this shell. If it is soluble, the ions need to be addressed as in the classic case. Furthermore the shell might increase the uptake by the cells. If the ions and the uptake are not critical the categorization can continue with the next layer. With this not perfect but pragmatic approach, the surface layers can be addressed with very limited additional efforts. Most criteria are based on classically tabulated data. Including a rating system like the precautionary matrix approach might even address the fact that some parameters are not always Yes/No, e.g. solubility, ion toxicity and uptake. T2 - OECD Expert Meeting on Grouping and Read Across for the Hazard Assessment of Manufactured Nanomaterials CY - Brussels, Belgium DA - 13.04.2016 KW - OECD KW - Nanoparticles KW - Nanomaterials KW - Grouping KW - Nano PY - 2016 AN - OPUS4-35774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bantz, C. A1 - Koshkina, Olga A1 - Lang, Thomas A1 - Galla, H.-J. A1 - Kirkpatrick, C.J. A1 - Stauber, R.H. A1 - Maskos, M. T1 - The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions N2 - Due to the recent widespread application of nanomaterials to biological systems, a careful consideration of their physiological impact is required. This demands an understanding of the complex processes at the bio–nano interface. Therefore, a comprehensive and accurate characterization of the material under physiological conditions is crucial to correlate the observed biological impact with defined colloidal properties. As promising candidates for biomedical applications, two SiO2-based nanomaterial systems were chosen for extensive size characterization to investigate the agglomeration behavior under physiological conditions. To combine the benefits of different characterization techniques and to compensate for their respective drawbacks, transmission electron microscopy, dynamic light scattering and asymmetric flow field-flow fractionation were applied. The investigated particle systems were (i) negatively charged silica particles and (ii) poly(organosiloxane) particles offering variable surface modification opportunities (positively charged, polymer coated). It is shown that the surface properties primarily determine the agglomeration state of the particles and therefore their effective size, especially under physiological conditions. Thus, the biological identity of a nanomaterial is clearly influenced by differentiating surface properties. KW - Nanomaterial characterization KW - Physiological conditions KW - Surface properties KW - Silica nanoparticles KW - Siloxane nanoparticles KW - Nanoparticles KW - Colloids KW - Silica KW - Polyorganosiloxane KW - Siloxane KW - Characterization KW - Transmission electron microscopy KW - TEM KW - Cryo-TEM KW - Asymetrical flow field-flow fractionation KW - AF-FFF KW - Field-flow fractionation KW - FFF KW - Dynamic light scattering KW - DLS KW - PCS PY - 2014 DO - https://doi.org/10.3762/bjnano.5.188 SN - 2190-4286 VL - 5 SP - 1774 EP - 1786 CY - Frankfurt, M. AN - OPUS4-32575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Siebler, Daniel A1 - Lothongkam, Chaiyaporn A1 - Rohwetter, Philipp A1 - Habel, Wolfgang A1 - Heidmann, G. T1 - Fluorescent fiber optical partial discharge sensor in high-voltage cable facilities N2 - New sensors for the detection of partial discharges (PDs) in high-voltage (HV) cable accessories are being de-veloped consisting of a fluorescent polymer optical fiber (F-POF) as sensing element. Depending on the fiber material F-POFs can be attached to and even integrated into the translucent silicone rubber insulation of HV cable terminations. As the embedment into the insulation material plays an important role, the sensor should not weaken the dielectric strength of the insulation material and should not be the origin of PD incidents. A sensor consisting of a commercial F-POF has been tested in the high-voltage lab regarding its PD detection ability un-der AC in comparison to a conventional electrical sensor. New silicone rubber F-POF (Si-F-POF) fiber models functionalized with coumarin dyes have been produced. The optical properties of these dye functionalized silox-anes are presented. These potential sensor fibers are highly flexible and might be embeddable at medium to high-voltage level. An additional way to further improve the level of PD light detection is to modify the translucent type of silicone rubber used in HV cable accessories in terms of optical transparency. In this context we present our first results of the optical and mechanical properties of new elastomeric transparent silicone materials specif-ically designed for the application as HV insulation materials in stress cones. T2 - POF 2013 - 22nd International conference on plastic optical fibers CY - Búzios, Rio de Janeiro, Brazil DA - 11.09.2013 KW - Polymer optical fiber KW - Fluorescence sensor KW - Partial discharge monitoring KW - High-voltage power cable KW - Silicone rubber KW - Fluorescence dye KW - Nanoparticles PY - 2013 SP - 322 EP - 327 CY - Rio de Janeiro, Brazil AN - OPUS4-30266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Natte, Kishore A1 - Orts Gil, Guillermo A1 - Unger, Wolfgang T1 - Morphology of nanoparticles - A characterization using high-resolution SEM N2 - Potential candidates of reference nano-materials are manufactured and systematically characterized in particular with respect to their morphology (shape, size and size distribution) in the frame of the running large European project NanoValid. By exploiting the transmission operation mode in a SEM, known as T-SEM, it is demonstrated by means of three representative examples of nanoparticles how a quick morphological inspection up to a complete, metrological characterization is feasible. KW - Nanoparticles KW - SEM KW - TEM KW - T-SEM KW - NanoValid PY - 2013 SN - 1439-4243 SN - 1863-7809 VL - 15 IS - 1 SP - 54 EP - 56 PB - GIT-Verl. CY - Darmstadt AN - OPUS4-27925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koshkina, Olga A1 - Bantz, C. A1 - Würth, Christian A1 - Lang, Thomas A1 - Resch-Genger, Ute A1 - Maskos, Michael T1 - Fluorophore-labeled siloxane-based nanoparticles for biomedical applications N2 - We present the synthesis and characterization of multifunctional fluorophore-labeled poly(organosiloxane) nanoparticles with core-shell architecture, where the fluorescent dye is incorporated into the core. Grafting of heterobifunctional poly(ethylene oxide) (PEO) onto the particle surface leads to water-soluble biocompatible nanoparticles. Two different strategies have been used for the synthesis: The encapsulation of dye-labeled monomers during the polycondensation with additional PEO coating and subsequent dye labeling by covalent attachment of the fluorescent dye rhodamine B to the (chloromethylphenyl)siloxane groups in the core after polymerization and grafting of PEO onto the surface. Comparison of the fluorescence quantum yields of the nanoparticles before and after PEO coating show a decrease in quantum yield after PEO coating. KW - Biocompatibility KW - Core-shell KW - Fluorescence KW - Fluorescence quantum yield KW - Nanoparticles KW - PEO PY - 2011 DO - https://doi.org/10.1002/masy.201100041 SN - 1022-1360 SN - 0258-0322 SN - 1521-3900 VL - 309/310 IS - 1 SP - 141 EP - 146 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Behnke, Thomas A1 - Drescher, Daniela A1 - Kneipp, Janina A1 - Resch-Genger, Ute T1 - Lifetime-based discrimination between spectrally matching vis and NIR emitting particle labels and probes N2 - Increasing the information content from bioassays which requires robust and efficient strategies for the detection of multiple analytes or targets in a single measurement is an important field of research, especially in the context of meeting current security and health concerns. An attractive alternative to spectral multiplexing, which relies on fluorescent labels excitable at the same wavelength, yet sufficiently differing in their emission spectra or color presents lifetime multiplexing. For this purpose, we recently introduced a new strategy based on 'pattern-matching' in the lifetime domain, which was exemplary exploited for the discrimination between organic dyes and quantum dot labels revealing multi-exponential decay kinetics and allowed quantification of these labels. Meanwhile, we have succeeded in extending this lifetime multiplexing approach to nanometer-sized particle labels and probes absorbing and emitting in the visible (vis) and near-infrared (NIR) spectral region. Here, we present a first proof-of-principle of this approach for a pair of NIR-fluorescent particles. Each particle is loaded with a single organic dye chosen to display very similar absorption and emission spectra, yet different fluorescence decay kinetics. Examples for the lifetime-based distinction between pairs of these fluorescent nanoparticles in solution and in cells are presented. The results underline the potential of fluorescenc lifetime multiplexing in life science and bioanalysis. KW - Fluorescence KW - Fluorescence lifetime imaging microscopy KW - FLIM KW - Lifetime Multiplexing KW - Particle Label KW - Near-infrared KW - NIR KW - Cell imaging KW - Nanoparticles PY - 2011 DO - https://doi.org/10.1117/12.881442 SN - 1605-7422 VL - 7905 SP - 79051F-1 EP - 79051F-9 PB - SPIE, The International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-23637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Behnke, Thomas A1 - Brehm, Robert A1 - Grabolle, Markus A1 - Hennig, Andreas A1 - Hoffmann, Angelika A1 - Hoffmann, Katrin A1 - Linck, Lena A1 - Lochmann, Cornelia A1 - Pauli, Jutta A1 - Spieles, Monika A1 - Würth, Christian T1 - Funktionelle Chromophor-Systeme, innovative Validierungskonzepte und rückführbare Standards für die fluoreszenzbasierte multiparametrische Bioanalytik N2 - Unter dem Motto „Innovation und Qualitätssicherung in der (Bio)Analytik“ werden in der Arbeitsgruppe Fluoreszenzspektroskopie der BAM, Bundesanstalt für Materialforschung und -prüfung, funktionelle Chromophor-Systeme, einfache Signalverstärkungs- und Multiplexingstrategien sowie innovative Validierungs- und rückführbare Standardisierungskonzepte für verschiedene fluorometrische Messgrößen und Methoden entwickelt. Im Mittelpunkt stehen dabei molekulare Fluorophore, Nanokristalle mit größenabhängigen optischen Eigenschaften (sogenannte Quantenpunkte, QDs) und fluoreszierende Partikel variabler Größe sowie Sonden und Sensormoleküle für neutrale und ionische Analyte und für die Charakterisierung von funktionellen Gruppen. Dabei erfolgen auch methodische Entwicklungen für die Fluoreszenzspektroskopie, die Fluoreszenzmikroskopie, die Milcrofluorometrie, die Sensorik und die Mikroarraytechnologie. Ziele sind u. a. das Design und die Untersuchung von multiplexfähigen selektiven und sensitiven Sonden für die Biomarkeranalytik, die Entwicklung von Methoden zur Charakterisierung der signalrelevanten Eigenschaften dieser Chromophor-Systeme und zur Charakterisierung von funktionellen Gruppen an Oberflächen und ihre Validierung sowie die Entwicklung und Bereitstellung von formatadaptierbaren, flexibel ersetzbaren Standards für die fluoreszenzbasierte Multiparameteranalytik. T2 - 5. Senftenberger Innovationsforum Multiparameteranalytik CY - Senftenberg, Deutschland DA - 10.03.2011 KW - Multiparametric KW - Multiplexing KW - Fluorescence KW - Nanoparticles KW - NIR dyes KW - Surface analysis KW - Quantum yield KW - Quantum dot KW - Lifetime PY - 2011 SP - 86 EP - 108 CY - Senftenberg AN - OPUS4-23635 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Bresch, Harald A1 - Dörfel, Ilona A1 - Fink, C. A1 - Giese, A. A1 - Prietzel, Claudia A1 - Seeger, Stefan A1 - Walter, J. T1 - Examination of airborne brake dust T2 - JEF 2010 - 6th European conference on braking CY - Lille, France DA - 2010-11-24 KW - Brake dust KW - Nanoparticles KW - Size-distribution PY - 2010 SP - 1 EP - 6(?) AN - OPUS4-22655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Descalzo López, Ana Belén A1 - Zhu, Shengchao A1 - Fischer, Tobias A1 - Rurack, Knut ED - Demchenko, A.P. T1 - Optimization of the coupling of target recognition and signal generation N2 - Fluorescent reporters that literally "light up" upon binding of a target species are particularly interesting from an analytical point of view. This contribution introduces the main signaling concepts in fluorescent probe research, discusses strategies toward their optimization in terms of signal output, and highlights the wealth of alternative protocols that has been realized in the past two decades to create signaling systems with luminescence amplification features. KW - Dyes KW - Fluorescence KW - FRET KW - Molecular Recognition KW - Nanoparticles PY - 2010 SN - 978-3-642-04699-5 DO - https://doi.org/10.1007/978-3-642-04701-5_2 N1 - Serientitel: Springer Series on Fluorescence – Series title: Springer Series on Fluorescence VL - 9 IS - 1 SP - 41 EP - 106 PB - Springer AN - OPUS4-21941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN ED - Boulmer-Leborgne, C. ED - Dinescu, G. ED - Krüger, Jörg ED - Orlando, S. ED - Habermeier, H.-U. T1 - Topical Issue: Laser and Plasma Processing for Advanced Materials / Journal of Optoelectronics and Advanced Materials, Vol. 12, No. 3, March 2010 N2 - Laser and plasma processing of materials is a rapidly growing field in fundamental science and materials technology requiring both a multidisciplinary approach and a wide-ranging knowledge. The topical issue “Laser and plasma processing for advanced materials” of the Journal of Optoelectronics and Advanced Materials covers a number of recent research highlights. The production of thin functionalized films, nanoparticles and nanocomposites using pulsed laser ablation (PLA) and deposition (PLD) or plasma treatment is discussed in a number of papers. Additionally, experiments using matrix assisted pulsed laser evaporation (MAPLE) are described. It is shown in this book that nanoparticles are generated and/or processed by laser or plasma interaction in very different environments ranging from gaseous and liquid to solid phase. Material properties change if the particle size is reduced below a critical limit allowing e.g. optical, electronic, biomedical, and environmental applications. Micro- and nanostructuring of surfaces (2D) and within the bulk of transparent materials (3D) is presented in various articles. In many cases, ultrashort laser pulses were applied. Furthermore, nanoparticles interacting with laser radiation can be used for nanostructuring purposes. Apart from experimental investigations, numerical modeling of the interaction of femtosecond laser pulses with materials has also been performed to understand structure formation theoretically. Especially for bio-functionalization, selective deposition of sensitive materials (e.g. proteins, cells) on surfaces is needed. A sophisticated process used for this purpose is known as laser induced forward transfer (LIFT). Recent findings regarding the LIFT method are depicted in this issue. Laser annealing of implanted dopants and thin films aiming to enhance structural and electrical properties, sensor dicing by laser radiation, and laser or plasma surface modification for the improvement of solar cells or polymer wettability change are but a few of the subjects focusing on applied research. Additionally, hybrid processes combining plasma spraying and laser-induced melting to control microstructure of coatings are introduced. Last but not least, achievements regarding analytical techniques are outlined. Laser induced breakdown spectroscopy (LIBS) make up a large part of this class. Additionally, the contributions to optical emission spectroscopy and mass spectrometry of plasma processes are significant. KW - Pulsed laser ablation KW - Evaporation KW - Deposition KW - Laser and plasma interaction KW - Laser micro- and nanostructuring KW - Nanoparticles KW - Laser induced forward transfer KW - Laser surface modifications KW - Plasma treatment PY - 2010 SN - 1454-4164 SP - 421 EP - 789 PB - INOE & INFM CY - Bucharest AN - OPUS4-21619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Böhning, Martin A1 - Goering, Harald A1 - Hao, Ning A1 - Mach, Reinhard A1 - Schönhals, Andreas ED - Cassidy, P. T1 - Polycarbonate/SiC nanocomposites - Influence of nanoparticle dispersion on molecular mobility and gas transport T2 - 7th International Symposium on Polymers for Advanced Technologies CY - Fort Lauderdale, FL, USA DA - 2005-09-21 KW - Nanocomposites KW - Nanoparticles KW - Polycarbonates KW - Dielectric properties KW - Gas permeation PY - 2005 VL - 16 IS - 2-3 SP - 262 EP - 268 PB - Wiley CY - Chichester AN - OPUS4-7062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Giesen, Charlotte T1 - ICP-MS and Elemental Tags for the Life Sciences N2 - Die induktiv gekoppelte Plasma Massenspektrometrie (ICP-MS) wurde aufgrund ihrer hohen Empfindlichkeit, des großen linearen dynamischen Messbereichs und ihrer Multielementfähigkeit für die Analytik von Biomolekülen eingesetzt. Jedoch wird das Potential dieser Technik außerhalb der ICP-Gemeinschaft selten genutzt. Daher wurden in dieser Arbeit ICP-MS-basierte Immunoassays für medizinische (Krebsdiagnostik, Toxizitätsstudien zu Cisplatin), biochemische (DNA Mikroarray, Einzelzellanalytik) und umweltrelevante (Lebensmittelanalytik) Anwendungen entwickelt. Die Detektion erfolgte durch chemische Markierungen. Die Laserablation (LA)-ICP-MS wurde für die direkte Analyse von festen Proben wie Mikroarrays und Gewebedünnschnitten eingesetzt. Ein Immunoassay zur Ochratoxin A (OTA) Bestimmung in Wein wurde entwickelt, und die ICP-MS mit der herkömmlichen photometrischen Detektion verglichen. Die Nachweisgrenze betrug 0.003 μg L-1, und der Quantifizierungsbereich lag zwischen 0.01 und 1 μg L-1 für beide Methoden. Für die LA-ICP- MS basierte DNA Mikroarray Detektion wurden Goldnanopartikel über Streptavidin-Biotin Bindungen eingeführt. In der immunhistochemischen Diagnostik werden üblicherweise für einen Patienten bis zu 20 Krebsmarker abgefragt, was zu einer Reihe von zeitaufwändigen Färbeprotokollen führt. Daher wurde hier die LA-ICP-MS als eine neue, multiplexfähige Detektionsmethode für die Analytik an Gewebeschnitten entwickelt. Hierzu wurden Lanthanide für die Detektion von bis zu drei verschiedenen Tumormarkern in Brustkrebsgewebe eingesetzt. Darüber hinaus wurde mittels Iodmarkierung eine LA-ICP-MS Methode entwickelt, in der ein 4 μm Laserstrahl ausreichend war für die Darstellung von einzelnen Zellen und Zellkernen. Iod wurde außerdem als interner Standard für Gewebeschnitte verwendet. Zusätzlich wurden Pt-Protein Komplexe mit 1D und 2D Gelelektrophorese getrennt und mit LA-ICP-MS analysiert. Die hohe räumliche Auflösung dieser Technik wurde anhand der Detektion von platinierten Proteinen in Rattennierengewebe auch in einer aktuellen Studie zur Toxizität von Cisplatin und dem daher notwendigen Schutz der Niere unter Beweis gestellt. N2 - Inductively coupled plasma mass spectrometry (ICP-MS) has been applied for the analysis of biomolecules due to its high sensitivity, wide linear dynamic range, and multielement capabilities. However, outside the elemental MS community the potential of this technique, e.g. for life sciences applications, is not yet fully exploited. Thus, the development of ICP-MS-based (immuno) assays for a wide range of medical (cancer diagnostics, cisplatin toxicity studies), biochemical (DNA microarray, single cell analysis), and environmental (analysis of comestible goods) applications was accomplished by utilization of chemical labels. Laser ablation (LA)-ICP-MS was employed for the direct analysis of solid samples like microarrays and thin tissue sections. An immunoassay was developed for ochratoxin A (OTA) determination in wine, and ICP-MS detection was compared to conventional photometry by gold nanoparticle tagging and horseradish peroxidase, respectively. Detection limits of the assay were optimized to 0.003 μg L-1, and the quantification range was 0.01–1 μg L-1 for both methods. For LA-ICP-MS-based DNA microarray detection, gold nanoparticle tags were specifically introduced via a streptavidin-biotin linkage. In immunohistochemistry (IHC), up to 20 tumor markers are routinely evaluated for one patient and thus, a common analysis results in a series of time consuming staining procedures. Hence, LA-ICP- MS was elaborated as a detection tool for a novel, multiplexed IHC analysis of tissue sections. Different lanthanides were employed for the simultaneous detection of up to three tumor markers (Her 2, CK 7, and MUC 1) in a breast cancer tissue. Additionally, iodine was employed as a labeling reagent, and a new LA-ICP-MS method for single cell and cell nucleus imaging was developed at 4 μm laser spot size. Iodine was also applied as a new internal standard for tissue samples. Moreover, Pt-protein complexes separated by an optimized 1D and 2D gel electrophoresis were analyzed by LA-ICP-MS. The high spatial resolution of this technique was further demonstrated in a current study of cisplatin toxicity and renal protective strategies in rat kidney tissue by detecting platinated proteins. T3 - BAM Dissertationsreihe - 83 KW - ICP-MS KW - Life Sciences KW - Nanoparticles KW - Elemental Tags PY - 2012 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-758 SN - 978-3-9814634-7-7 SN - 1613-4249 VL - 83 SP - 1 EP - 199 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-75 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -