Pharmacokinetics: the plasma half-life is composed of distribution phase (t1/2,α) and elimination phase (t1/2,β) as indicated in purple and blue colors, respectively. Shown are blood half-life examples obtained from ZW800-1 (28) (a small molecule, 1 nm in HD), QD-Cys (25) (a small nanoparticle, 5 nm in HD), and QD-PEG (26) (a typical-sized nanoparticle, 8 nm in HD)