Aggregation-induced emission (AIE) nanoparticles have been shown
promise for fluorescence bioimaging and photodynamic therapy due to the good
combination of nanoparticles and organic dyes or photosensitizers. Among several kinds of
AIE nanoparticles, those that are capsulated with nanographene oxides (NGO) are easy to
make, size-tunable, and have proven to be very stable in deionized water. However, the
stability in saline solution still needs improvement for further applications in chemical or
biomedical fields, and the efficacy of photodynamic therapy using NGO-capsulate AIE
photosensitizers has not been evaluated yet. Herein, we modified NGO with polyethylene
glycol (PEG) to improve the stability of NGO-capsulated AIE nanoparticles in phosphate
buffer saline. Furthermore, by combining this modification method with a dual-functional
molecule which has both typical AIE property and photosensitizing ability, we performed
both two-photon fluorescence bioimaging and photodynamic therapy in vitro and in vivo.
Our work shows that AIE nanoparticles capsulated with PEGylated nanographene oxide
can be a powerful tool for future bioimaging and photodynamic therapy applications.