intended receptor. A typical example is shown in Figure 9.20, where CdSe(ZnS)
quantum dots were functionalized with two different compounds; one of these is
attached at the surface (Figure 9.20a) and the other is localized in the cell nucleus
(Figure 9.20b).
It is well known that the incorporation of nanoparticles in polymers may lead, in
the case of chemical bonding at the particle surface, to additional optical phenomena. In this context, the most interesting area is the incorporation of
Figure 9.19 Comparison of absorption and
emission spectra of organic lumophores (FITC)
(a) and CdSe quantum dots (b) emitting
roughly at the same wavelength according to
Smith et al. [4]. (a) Absorption and emission
spectra of FITC. The characteristics of this class
of compound are relatively broad emission
spectra and a strong limitation of an effective
absorption with respect to shorter wavelengths.
Compared to quantum dots, the significantly
smaller size of the organic lumophore
molecules may be a significant advantage.
(b) Absorption and emission spectra of CdSe
nanoparticles. Compared to the spectra of the
organic lumophore depicted in Figure 9.19a,
the emission spectrum is more narrow and the
absorption in the UV range is more effective.
Therefore, the selection of an excitation source
for luminescent nanoparticles is less critical as
compared to organic lumophores.
224j 9 Optical Properties of Nanoparticles
quantum dots were functionalized with two different compounds; one of these is
attached at the surface (Figure 9.20a) and the other is localized in the cell nucleus
(Figure 9.20b).
It is well known that the incorporation of nanoparticles in polymers may lead, in
the case of chemical bonding at the particle surface, to additional optical phenomena. In this context, the most interesting area is the incorporation of
Figure 9.19 Comparison of absorption and
emission spectra of organic lumophores (FITC)
(a) and CdSe quantum dots (b) emitting
roughly at the same wavelength according to
Smith et al. [4]. (a) Absorption and emission
spectra of FITC. The characteristics of this class
of compound are relatively broad emission
spectra and a strong limitation of an effective
absorption with respect to shorter wavelengths.
Compared to quantum dots, the significantly
smaller size of the organic lumophore
molecules may be a significant advantage.
(b) Absorption and emission spectra of CdSe
nanoparticles. Compared to the spectra of the
organic lumophore depicted in Figure 9.19a,
the emission spectrum is more narrow and the
absorption in the UV range is more effective.
Therefore, the selection of an excitation source
for luminescent nanoparticles is less critical as
compared to organic lumophores.
224j 9 Optical Properties of Nanoparticles