Construction of Light-Harvesting Polymeric Vesicles in Aqueous Solution with Spatially Separated Donors and Acceptors

This communication describes polymer vesicles self-assembled from hyperbranched polymers (branched polymersomes (BPs)) as scaffolds, conceptually mimicking the natural light-harvesting system in aqueous solution. The system is constructed with hydrophobic 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) as donors encapsulated in the hydrophobic hyperbranched cores of the vesicles and the hydrophilic Rhodamine B (RB) as acceptors incorporated on the surface of the vesicles through the cyclodextrin (CD)/RB host-guest interactions, through which the donors and acceptors are spatially separated to effectively avoid the self-quenching between donors. This vesicular light harvesting system has presented good energy transfer efficiency of about 80% in water, and can be used as the ink to write multiclolor letters. In addition, due to the giant dimension of BPs, the real-time fluorescent images of the vesicles under an optical microscope can be observed to prove the light-harvesting process. It is supposed that such a vesicular light-harvesting antenna can be used to construct artificial photosynthesis systems in the future.