Synthesis of Poly(methyl methacrylate) Labeled with Fluorescein Moieties via Atom Transfer Radical Polymerization

Fluorescein chromophore‐labeled poly(methyl methacrylate) (PMMA) was prepared via atom transfer radical polymerization (ATRP) with two novel bromine‐containing fluorescein derivatives, 3,6‐bi(2′‐bromo‐2′‐methyl‐propionic acid) fluorescein ester (Fla‐Br) and 3‐(2′‐bromo‐2′‐methyl‐propionic acid) fluorescein ester (Flb‐Br), as the functional initiators, and CuBr/PMDETA as the catalyst, respectively. The above mentioned fluorescein containing bromine were synthesized in our lab. The ATRP of PMMA was proved in a controlled fashion. The resultant PMMA with narrow molecular weight distribution was endowed with the fluorescein chromophore incorporated into the polymer backbone. The presence of the fluorescein labeling of the polymers was confirmed by ¹H‐NMR and GPC trace under UV detector. The UV spectroscopy and fluorescence measurements of the resultant polymer gave further evidence of the functionality of the fluorescein labeling.