Applications of particle-tracking analysis to the determination of size distributions and concentrations of nanoparticles in environmental, biological and food samples

The manufacture of nanoparticles (NPs) and nanomaterial-based products is rapidly increasing and their possible occurrence in environment, food or biological tissue is becoming of concern for ecological and human health. However, there is a lack of suitable methods to analyze and to characterize NPs in low concentrations in complex matrixes. We compare several particle-tracking methods using video microscopy and a new technique called nanoparticle-tracking analysis (NTA). Video microscopy has been widely applied to investigate particle movement in biological samples, micro-rheology, and velocity profiles in fluids, whilst NTA was devised for determination of size distributions and concentrations in liquid samples. We critically discuss the advantages and the limitations of NTA for such applications.