Fabrication of inverse-opal lysozyme-imprinted polydopamine/polypyrrole microspheres with near-infrared-light-controlled release property.

The combination of the molecular imprinting technology and porous materials is a promising way to obtain high-efficient selective adsorption and separation materials for bioactive macromolecules. In this work, we developed a novel approach to prepare near-infrared (NIR)-light-response inverse-opal lysozyme (Lyz)-imprinted polydopamine/polypyrrole (IO-PDA/PPy-MIP) composite microspheres using micron-sized SiO2 colloidal crystal microspheres as the sacrificed template. The pore size of the IO-PDA/PPy-MIP microspheres can be tuned from 200 to 800 nm by the size of silica nanoparticles which self-assemble to form the template SiO2 colloidal crystal microspheres. The IO-PDA/PPy-MIP microspheres show a rapid selective adsorption ability for Lyz due to the inverse-opal macroporous structure. The adsorption capacity exceeds 800 mg/g within 20 min, and the imprinting factor is as high as 24. The bound Lyz molecules can be released rapidly from IO-PDA/PPy-MIP microspheres triggered by the irradiation of NIR laser and remain enough bioactivity to decompose Escherichia coli efficiently. The prepared IO-PDA/PPy-MIP microspheres also exhibit excellent structure stability and good recyclability. The adsorption capacity can remain up to 90% of the initial value after 5 times recycle. This work provides not only a method to prepare novel NIR-light-response inverse-opal macroporous molecularly imprinted microspheres, but also a new perspective on the design of selectively separation materials for the fast, high-efficient recognition and separation of biomacromolecules.