Photoswitchable fluorescent polymeric nanoparticles for rewritable fluorescence patterning and intracellular dual-color imaging with AIE-based fluorogens as FRET donors
Weibang Zhong,a  Xuyao Zeng,b  Jian Chen,*a  Yongxiang Hong,a  Lehui Xiaob  and  Peisheng Zhang*a

Photoswitchable fluorescent polymer nanoparticles (PFPNs) were constructed from an aggregation-induced emission (AIE) based fluorogen and a photochromic spiropyran-linked amphiphilic copolymer via a simple co-precipitation method. Possessing the reversible photoisomerization property and high fluorescence resonance energy transfer (FRET) efficiency, not only did the designed spiropyran-linked amphiphilic copolymer provide the PFPNs with excellent long-term stability (～5 weeks) in aqueous media, but also it could both efficiently and reversibly switch on/off the fluorescence emission of the AIE-based fluorogen upon irradiation with UV and visible light. It is worth noting that the high contrast dual-color characteristics written with PFPNs as rewritable fluorescence patterning can be tuned by altering the wavelength of the irradiation light. Moreover, the resultant PFPNs were successfully applied for intracellular dual-color imaging due to their outstanding cell-membrane permeability and rapid photo-responsiveness, as well as excellent repeatability properties.

http://pubs.rsc.org/en/content/articlelanding/2017/py/c7py00834a#!divAbstract

Polym. Chem., 2017,8, 4849-4855