Transmission electron microscopy (TEM) is a unique and
powerful tool for observation of nanoparticles. However, due to the
uneven spatial distribution of particles conventionally dried on copper
grids, TEM is rarely employed to evaluate the spatial distribution
of nanoparticles in aqueous solutions. Here, we present a microchip
nanopipet with a narrow chamber width for sorting nanoparticles from
blood and preventing the aggregation of the particles during the drying
process, enabling quantitative analysis of their aggregation/agglomeration
states and the particle concentration in aqueous solutions. This microchip
is adaptable to all commercial TEM holders. Such a nanopipet proves
to be a simple and convenient sampling device for TEM image-based
quantitative characterization.