Zwitterionic Ligands Bound to CdSe/ZnS Quantum Dots Prevent Adhesion to Mammalian Cells.

Zwitterionic materials are useful tools in material science and biology as they provide high water solubility while preventing non-specific interactions. Quantum dots (QDs) functionalized with zwitterionic and quaternary ammonium ligands were synthesized to investigate their interactions with the outer membrane of HeLa cells. Quaternary ammonium functionalized quantum dots adhered strongly to the cell surface while zwitterionic QDs had no cell adhesion. These results demonstrate that future non-interacting nanoparticles based on this design are possible.