AUTHOR=Roebben Gert , Kestens Vikram , Varga Zoltan , Charoud-Got Jean , Ramaye Yannic , Gollwitzer Christian , Bartczak Dorota , Geißler Daniel , Noble James , Mazoua Stephane , Meeus Nele , Corbisier Philippe , Palmai Marcell , Mihály Judith , Krumrey Michael , Davies Julie , Resch-Genger Ute , Kumarswami Neelam , Minelli Caterina , Sikora Aneta , Goenaga-Infante Heidi TITLE=Reference materials and representative test materials to develop nanoparticle characterization methods: the NanoChOp project case JOURNAL=Frontiers in Chemistry VOLUME=3 YEAR=2015 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2015.00056 DOI=10.3389/fchem.2015.00056 ISSN=2296-2646 ABSTRACT=

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.