TEM analysis of nanoparticle dispersions with application towards the quantification of in vitro cellular uptake

TEM analysis of nanoparticle dispersions in solution has previously been limited, in the main, to the measurement of primary particle size due to the drying effects that occur during sample preparation. We show that solutions prepared for TEM by plunge freezing specimen grids coated with a blotted solution is a sensitive and potentially representative route to measuring a nanoparticle dispersion. We have started to benchmark the technique against the more commonly used dynamic light scattering method and show that the TEM route is potentially more sensitive route to counting individual nanoparticles in a dispersion that also contains nanoparticle agglomerates. Accurate measurement of nanoparticle dispersion in biological solutions could be a key step in the application of nanoparticles in medicine.