Improved non-invasive Optical Coherence Tomography detection of different engineered nanoparticles in food-mimicking matrices

• Repeatable OCT procedure for different hybrid nanomaterials.
• Complex averaging procedure improves S/N ratio.
• First-time non-invasive testing on silica nanomaterial as food additive.

Food industry and regulators require fast and reliable analytical methods for quality control. This especially counts for the detection of engineered nanomaterials (ENMs) in food products. Respective EU regulation is in force, but the development of appropriate methods is still underway. This paper updates the scope of Optical Coherence Tomography (OCT) for ENM/food matrix analysis. A range of nanomaterials and composites – Au@SiO2, Ag, Ag@SiO2 and SiO2 – in a simplified food matrix was investigated. The earlier finding of linear dependencies between concentration in the dispersion and light responses could be reproduced. Being able to analyse non-invasively for a relevant industrial compound such as SiO2, makes OCT an excellent candidate for screening purposes.