Prospects for Organic Dye Nanoparticles - Advanced Fluorescence Reporters in Chemistry and Biology - page 294

Fig. 4 PIC dye nanoparticles prepared by the ion-association method. (1) Particle size distribu-
tions (determined by the dynamic light scattering technique) and the corresponding electron
micrographs of the dye nanoparticles. The average diameter can be controlled by tuning the
molar ratio of TPB to PIC + ( [TPB ]/[PIC + ]. With an increase in the molar ratio, the average

diameter decreased. (2) Absorption spectra of PIC nanoparticles in aqueous solution with different
sizes (125 and 64 nm in diameter), exhibiting size-dependent peak shift of the 0-0 band. The
spectrum of the aqueous PIC-Br monomer solution is also shown

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decreased, the 0-0 band slightly shifted to shorter wavelength. This size-dependent
phenomenon might have originated from that of the surface-to-volume ratio
of nanoparticles that can induce matrix softening due to surface distortion.