Biomedical Engineering Reference
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Fig. 4.14 Distribution of fluorescence maxima of single PP molecules on SiO 2 ( a )andPPin
in nanoassemblies ( b ). For comparison, distributions are shown for PP in a spin-coated PMMA
film ( c ). Fluorescence maxima have been obtained by fitting the PP fluorescence spectra by two
Gaussian lines. Adapted from [ 94 ] with permission from the Intern. Journal of Mol. Sciences @
2009
various conformations of the bay groups (see Fig. 4.3 ) resulting in a broad distribu-
tion of the fluorescence maxima. The corresponding distribution of conformations
and thus the fluorescence spectra depends on the local environment such as the
embedding matrix. Figure 4.14 shows typical distributions of fluorescence maxima
forPPmoleculesonanSiO 2 surface, in QD-PP nanoassemblies and in a PMMA
polymer film, correspondingly. Comparison of these distributions reveals that the
QD-PP nanoassembly formation favors conformations in the short wavelength
range becoming more equivalent to the distribution observed for PMMA, which is
a rigid matrix. Therefore the comparative spectral range of nanoassemblies reflects
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