White-light fluorescent nanoparticles from self-assembly of rhodamine B-anchored amphiphilic poly(poly(ethylene glycol)methacrylate)-b-poly(glycidyl methacrylate) block copolymer

Rhodamine B (RhB)-anchored amphiphilic poly(poly(ethylene glycol)methacrylate)-b-poly(glycidyl methacrylate) block copolymer (PPEGMA-b-PGMA/RhB) has been prepared by a sequential atom transfer radical polymerization and post-functionalization of RhB. The chemical structure of PPEGMA-b-PGMA/RhB is characterized with gel-permeation chromatography, Fourier-transform infrared spectroscopy, and 1H nuclear magnetic resonance spectroscopy. PPEGMA-b-PGMA/RhB has shown self-assembly behaviors in tetrahydrofuran and aqueous solutions. The RhB aggregation induced with the inter-molecular interaction of RhB results in the various core-shell structures of the assembled nanoparticles. The photoluminescent properties of the PPEGMA-b-PGMA/RhB nanoparticles are structure-dependent and exhibit yellow-light, blue-light, and white-light emissions. The fluorescent organic nanoparticles of PPEGMA-b-PGMA/RhB in aqueous solution show low cytotoxicity and have been used as a bio-dye for cell labelling. Internalization of PPEGMA-b-PGMA/RhB nanoparticles into HELA cells to exhibit fluorescent images has been demonstrated.