Figure 5.
Quantum dot (QD) coatings and their effects on particle size and nonspecific binding. (a) QD size strongly depends on the surface coating; PEGylation (left) and amphiphilic polymers (middle) add considerably to the overall size. Size minimization is possible with the use of multidentate polymer ligands (right), which can wrap around the QD in a “loops-and-trains” conformation. (b) Charge reduction through the incorporation of PEG or −OH functional groups dramatically decreases nonspecific binding of QDs in cells and tissues. Abbreviation: PEG, polyethylene glycol.