Nanocrystals and Nanoparticles Versus Molecular Fluorescent Labels as Reporters for Bioanalysis and the Life Sciences: A Critical Comparison - Advanced Fluorescence Reporters in Chemistry and Biology - page 10

Table 2 Methods for water transfer
Method Applications

Electrostatic
stabilization

-Labeled with immuno-
molecules,
QDs recognized specific
antigens/antibodies
-DNA immobilization to QDs
surfaces and possibility of
hybrid assemblies [ 35 ]
-Coupled to transferrin, QDs
underwent receptor-
mediated endocytosis in
cultured HeLa cells

O

O -

S

NH 3 +

S

Ligand exchange with small charged
adsorbants, e.g., 3-mercaptopropionic
acid (MPA) [ 34 ]

SO -

SO -

O P

Intercalation with charged surfactants [ 36 ]

Steric
stabilization

-In vivo cancer targeting and
imaging
-Conjugation with DNA and
in vivo imaging
(embryogenesis) [ 36 ]
-Encoding of cells [ 38 ]
-Noninvasive in vivo imaging
with localization depending
on surface coating [ 39 ]

PEG

PEG

O P

PEG

PEG

Intercalation with bulky, uncharged
molecules, e.g., polyethyleneglycol [ 37 ]

( continued )

of the valence and conduction band etc.) if the dimensions of the relevant structural
features interfere with the delocalized nature of the electronic states. For semicon-
ductor QDs, such quantum-size effects occur typically for sizes in the range of a