Figure 2. The anatomy of quantum dots (adapted from [82]). (A) QDs contain a semiconducting core-shell. The surface can be coated with hydrophilic, hydrophobic, and amphiphilic ligands (common coating molecules are shown) which can be further linked with proteins, drugs, antibodies, and other compounds. (B) The emission spectra of QDs can be tuned by adjusting the size. (C) Fluorescence lifetimes of QD in comparison with other flurophores.