In biological systems, functions involving molecular recognition are crucial since key interactions in the body, such as protein-ligand and protein-protein interactions, depend on molecular binding events (e.g., hydrogen-bonding, π -stacking, and electrostatic interactions). Nanoparticles with molecular recognition properties found promising applications in biotechnology due to the advantages that the nanoscale offers, such as clear optical signatures and a high surface area-to-volume ratio. Nanoparticles exhibit size, shape, chemistry-dependent properties. Current nanoparticle synthesis methods produce heterogeneous populations. There is a need for a cost-effective and easy-to-use method which can enrich the populations of nanoparticles based on size, shape and chemistry. In this proposal, we will present such a toolbox to enable this kind of separations, use the enriched populations of nanoparticles in technological and scientific applications, and carry out nanotoxicology studies correlating the response of living systems to the exposure of homogeneous nanoparticles.