Small fluorescent nanoparticles at the nano–bio interface

Semiconductor quantum dots and metal nanoclusters are fluorescent nanoparticles with diameters in the few-nanometer range. In recent years, they have captured a great deal of attention as experimental tools in the life sciences for diverse applications including imaging, bioassays and therapy. It is crucially important to understand how these small nanoparticles behave in complex biological environments, especially in view of their potential for biomedical applications. In this review, we shall highlight recent advances in exploring the behavior of fluorescent nanoparticles at the nano–bio interface, including their interactions with proteins and cells, their intracellular stability as well as their in vivo behavior.