Redox-Active AIEgen-Derived Plasmonic and Fluorescent Core@Shell Nanoparticles for Multimodality Bioimaging

Multimodality
imaging is highly desirable for accurate diagnosis by achieving high
sensitivity, spatial–temporal resolution, and penetration depth
with a single structural unit. However, it is still challenging to
integrate fluorescent and plasmonic modalities into a single structure,
as they are naturally incompatible because of significant fluorescence
quenching by plasmonic noble-metal nanoparticles. Herein, we report
a new type of silver@AIEgen (aggregation-induced emission luminogen)
core–shell nanoparticle (AACSN) with both strong aggregated-state
fluorescence of the AIEgen and distinctive plasmonic scattering of
silver nanoparticles for multimodality imaging in living cells and
small animals. The AACSNs were prepared through a redox reaction between
silver ions and a redox-active AIEgen, which promoted synergistic
formation of the silver core and self-assembly of the AIEgen around
the core. The resulting AACSNs exhibited good biocompatibility and
high resistance to environmental damage. As a result, excellent performance
in fluorescence imaging, dark-field microscopy, and X-ray computed
tomography-based multimodality imaging was achieved.