Nanostructured Thermo-responsive Surfaces Engineered via Stable Immobilization of Smart Nanogels with Assistance of Polydopamine.

Thermo-responsive surfaces featured with nanostructures have found wide potential applications in biological and chemical fields. Herein, we report nanostructured thermo-responsive surfaces engi-neered via stable immobilization of thermo-responsive nanogels with assistance of polydopamine. The results show that the thin layer of polydopamine on the poly(N-isopropylacrylamide) (PNIPAM) nanogels nearly does not affect the thermo-responsive property of the nanogels. The stability of thermo-responsive nanogels on the substrate surfaces immobilized under different pH conditions of dopamine solutions are quatitively studied by fluid shearing experiments inside capil-laries, and the characterization results show that the strong interaction forces between the polydo-pamine layer on the substrate surfaces and the thermo-responsive nanogels are heavily depended on the oxidation state of dopamine molecules. With the proposed strategy, thermo-responsive nanostructured surfaces immobilized with PNIPAM nanogels on two-dimensional and three-dimensional substrate surfaces are generated to respectively achieve smart cell culture plates and smart gating membranes, which demonstrate versatile applications of the nanostructured thermo-responsive surfaces.