Mildly Rewritable Polymer Brushes Enabled by Multiple Hydrogen Bonds of Complementary Nucleobases.

Functional surfaces from rewritable polymer brushes find numerous applications. However, the rewritable properties mainly rely on surface structural variations or chemical compositions changes through stimuli-response, often confronting with low binding, poor reversibility, and harsh treatment conditions. Herein, we develop a robust supramolecular approach to fabricating mildly rewritable polymer brushes by harnessing multiple hydrogen bonds (MHBs) between bioinspired complementary nucleobases. A "grafting from" strategy is employed to prepare dense nucleobase-containing polymer brushes, which anchor complementary nucleobase-functionalized copolymers with distinct hydrophilic blocks for properties tunability. MHBs between complementary nucleobase-containing polymers are strong enough to tailor the surface properties regardless of chain lengths and chemical compositions of the hydrophilic blocks. As such, various rewritable polymer brushes with thermoresponsive, pH-responsive, and varied protein-resistant properties are generated and changed in between. More significantly, the dynamic reversibility of MHBs imparts excellent cyclic stability of properties variation to the rewritable polymer brushes. Finally, the controlled capturing and releasing of proteins in aqueous solutions are achieved, showcasing potential applications of the rewritable polymer brushes for the bioconcentration of proteins. Collectively, this work offers us with a novel and efficient strategy for tailoring surface properties of polymer brushes, which might amplify their applications in biomedical fields.