Reference materials and representative test materials to develop nanoparticle characterization methods: the NanoChOp project case

This paper illustrates how to use generic guidelines on the production of reference materials (RMs) for the selection and characterization of a common set of nanoparticle test materials for a collaborative research project on techniques to assess nanoparticles in biologically relevant media. It addresses the challenges related to the production of suspensions of nanoparticles with defined surface groups and monomodal size distributions, in casu suspensions of silica and titanium dioxide nanoparticles and CdSe/CdS/ZnS quantum dots. Several candidate 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 unwanted 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 the surface functionalization was investigated bymeasuring the capacity of the nanoparticles to be fluorescently labeled or to bind antibodies. For the three selected materials (aqueous suspensions of silica, aminated silica and CdSe/CdS/ZnS quantum dots) between-unit homogeneity and stability were investigated in terms of particle size and zeta potential. This paper illustrates how the outcome of the characterization process defines the status of the selected suspensions as 'representative test material' (recently defined in ISO TS 16195:2013) or as'reference material' (ISO Guide 30:2015), and how this status depends on their intended use. A range of practical tips for the processing of nanoparticle suspensions is offered, as well as conceptual guidance for the production of representative test materials and reference materials used in collaborative research projects on nanoparticle characterization and in other areas of measurement 43 science.

ROEBBEN Gert;  KESTENS Vikram;  VARGA Z.;  CHAROUD-GOT Jean;  RAMAYE Yannic;  GOLLWITZER Christian;  BARTCZAK Dorota;  GEISSLER Daniel;  NOBLE James E.;  MAZOUA Stephane;  MEEUS Nele;  CORBISIER Philippe;  PALMAI Marcell;  MIHÁLY Judith;  KRUMREY M.;  DAVIES Julie;  RESCH-GENGER Ute;  KUMARSWAMI Neelam;  MINELLI Caterina;  SIKORA Aneta;  GOENAGA INFANTE Heidi; 

2015-12-11

FRONTIERS RESEARCH FOUNDATION

JRC96873

https://publications.jrc.ec.europa.eu/repository/handle/JRC96873,   

10.3389/fchem.2015.00056,