Ultrabright
BODIPY-Tagged Polystyrene Nanoparticles:
Study of Concentration Effect on Photophysical Properties
- Publication date
- Publisher
Abstract
Fluorescent nanomaterials are invaluable
tools for bioimaging.
Polymeric nanoparticles labeled with organic dyes are very promising
for this purpose. It is thus very important to fully understand their
photophysical properties. New fluorescent core–shell nanoparticles
have been prepared. The outer part is a poly(ethylene glycol)-<i>block</i>-poly(acrylic acid) copolymer, and the core is a copolymer
of styrene and methacrylic BODIPY fluorophore. The hydrophilic and
hydrophobic parts are covalently linked, ensuring both stability and
biocompatibility. We prepared nanoparticles with increasing amounts
of BODIPY, from 500 to 5000 fluorophores per particles. Increasing
the concentration of BODIPY lowers both the fluorescence quantum yield
and the lifetime. However, the brightness of the individual particles
increases up to 8 × 10<sup>7</sup>. To understand the loss of
fluorescence efficiency, fluorescence decays have been recorded and
fitted with a mathematical model using a stretched exponential function.
This result gives an insight into the fluorophore arrangement within
the hydrophobic core
