A major challenge in nanomaterial science is to develop approaches that ensure that when administered in vivo, nanoparticles can be targeted to their requisite site of action. Herein we report the first approach that allows for cell-specific uptake of nanomaterials by a process involving reprogramming of the behavior of the ubiquitous protein corona of nanomaterials. Specifically, judicious surface modification of quantum dots with a small molecule that induces a protein-misfolding event in a component of the nanoparticle-associated protein corona renders the associated nanomaterials susceptible to cell-specific, receptor-mediated endocytosis. We see this chemical approach as a new and general method for exploiting the inescapable protein corona to target nanomaterials to specific cells.