Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-34964 Zeitschriftenartikel Roebben, G.; Kestens, V.; Varga, Z.; Charoud-Got, J.; Ramaye, Y.; Gollwitzer, Christian; Bartczak, D.; Geißler, Daniel; Noble, J.E.; Mazoua, S.; Meeus, N.; Corbisier, P.; Palmai, M.; Mihály, J.; Krumrey, M.; Davies, J.; Resch-Genger, Ute; Kumarswami, N.; Minelli, C.; Sikora, A.; Goenaga-Infante, H. Reference materials and representative test materials to develop nanoparticle characterization methods: the NanoChOp project case This paper describes the production and characteristics of the nanoparticle test materials prepared for common use in the collaborative research project NanoChOp (Chemical and optical characterization of nanomaterials in biological systems), in casu suspensions of silica nanoparticles and CdSe/CdS/ZnS quantum dots (QDs). This paper is the first to illustrate how to assess whether nanoparticle test materials meet the requirements of a "reference material" (ISO Guide 30, 2015) or rather those of the recently defined category of "representative test material (RTM)" (ISO/TS 16195, 2013). The NanoChOp test materials were investigated with small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and centrifugal liquid sedimentation (CLS) to establish whether they complied with the required monomodal particle size distribution. The presence of impurities, aggregates, agglomerates, and viable microorganisms in the suspensions was investigated with DLS, CLS, optical and electron microscopy and via plating on nutrient agar. Suitability of surface functionalization was investigated with attenuated total reflection Fourier transform infrared spectrometry (ATR-FTIR) and via the capacity of the nanoparticles to be fluorescently labeled or to bind antibodies. Between-unit homogeneity and stability were investigated in terms of particle size and zeta potential. This paper shows that only based on the outcome of a detailed characterization process one can raise the status of a test material to RTM or reference material, and how this status depends on its intended use. Lausanne Frontiers Media 2015 Frontiers in Chemistry 3 Article 56, 1 16 urn:nbn:de:kobv:b43-349644 10.3389/fchem.2015.00056 http://creativecommons.org/licenses/by/3.0/de/deed.de 2016-02-20 OPUS4-34966 Zeitschriftenartikel Sikora, A.; Bartczak, D.; Geißler, Daniel; Kestens, V.; Roebben, G.; Ramaye, Y.; Varga, Z.; Palmai, M.; Shard, A.G.; Goenaga-Infante, H.; Minelli, C. A systematic comparison of different techniques to determine the zeta potential of silica nanoparticles in biological medium The surface charge density of nanoparticles plays an important role in the way they interact with biological systems. The ability to measure the surface charge density of nanoparticles in biological media is therefore of importance in understanding the magnitude of such interactions. There are a number of methods which may be used to assess surface charge density through the measurement of electrophoretic mobility. In order to better understand the comparability of these methods, the ζ-potential of silica nanoparticles in water, buffer and serum-based biological medium was measured by one ensemble and two particle-by-particle techniques: electrophoretic light scattering (ELS), tunable resistive pulse sensing (TRPS) and zeta particle tracking analysis (z-PTA). To allow the comparability of results from different techniques, test samples were prepared according to an established protocol, although some variations were necessary to meet specific instrument requirements. Here we compare, for the first time, measurement results from the different techniques and discuss how modifications related to parameters such as environmental pH, dilution factor and presence of biomolecules influence the charge measurements. Cambridge RSC Publ. Royal Society of Chemistry 2015 Analytical methods 7 23 9835 9843 10.1039/C5AY02014J 2016-02-20