Reference materials are critical for checking the quality and metrological traceability of products, validating analytical measurement methods, and for instrument calibration. One challenge of nanoparticle reference materials is that the particle’s small size can lead to changes in the material properties over time. Nanoparticles also have different characteristics when compared to larger bulk materials or chemicals that must be fully quantified and monitored.
The composition, size, shape, charge and surface chemistry of nanoparticles are critical properties that need to be tightly controlled and measured during fabrication for any nanoparticle reference material. To ensure colloidal stability, the degree of particle aggregation and corresponding hydrodynamic size needs to be known and tracked with time. The concentration of all elements – both from the constituent materials of the nanoparticle and any residual chemicals in solution – must be quantified. In addition, measurement of the optical properties, surface area, solution pH, and endotoxin levels are also important for many reference materials.
NanoComposix has a long history of providing reference materials to the nanoparticle community. We supplied the Organisation for Economic Co-operation and Development (OECD) with silver nanoparticles for a multi-country study on the potential toxicity of nanoparticles, the National Cancer Institute (NCI) with silver particles for a large intralaboratory study, and provided materials to hundreds of nanotoxicology researchers to perform in-vitro and in-vivo experiments. In addition, we manufactured the 75 nm silver reference material (RM8017) for the National Institute of Standards and Technology (NIST), and are actively working with Japan’s National Institute of Advanced Industrial Science and Technology and other standards agencies to develop new nanoparticle standards. Our Ultra Uniform line of gold nanoparticles is being used for single particle ICP-MS calibration and also as a TEM calibration standard.