Reversible Light-Switching of Enzymatic Activity on Orthogonally Functionalized Polymer Brushes.

Copolymer brushes, composed of glycidyl methacrylate and a furan-protected maleimide-containing monomer, were grafted from radical initiators at the surface of irradiation-activated fluoropolymer foils. After postpolymerization modification with enzymatically active microperoxidase-11 and photochromic spiropyran moieties, the polymer brushes catalyzed the oxidation of 3,3'5,5'-tetramethylbenzidine. Exposure to either UV or visible-light allowed switching the turnover by more than 1 order of magnitude, as consequence of the reversible, light-induced spiropyran-merocyanine transition. The modified samples were integrated into an optofluidic device that allowed the reversible switching of enzymatic activity for several cycles under flow, validating the potential for application in smart lab-on-a-chip systems.