LAUSR

Fluorescent hyperbranched polysiloxane (HBPSi) has attached increasing attention due to its good biocompatibility. However, its emission mechanism remains an open question. Unfortunately, the excitation spectra of HBPSi are rarely systematically investigated and bear narrow excitation band, which hinders the emission mechanism study. Herein, we synthesized a series of novel HBPSi containing L-glutamic acid (HBPSi-GA). Surprisingly, these polymers have four excitation peaks and two emission peaks, which is caused by the energy transfer from free functional groups to heterogeneous electron delocalizations in different clusters. Meanwhile, the fluorescence and biocompatibility of HBPSi-GA are significantly improved with increasing L-glutamic acid. Furthermore, HBPSi-GA exhibits dual stimuli-responsive fluorescence to temperature and Fe3+, and potential application in cell imaging. This research possesses important guidance to develop multi-excitation unconventional fluorescent polymers.