Facile preparation of photonic and magnetic dual responsive protein imprinted nanomaterial for specific recognition of bovine hemoglobin

Stimulated response molecularly imprinted polymers (MIPs) have attracted wide attention not only because of their intriguing response to external stimuli, but also due to the desired molecular recognition ability. Herein, a novel dual responsive proteins MIPs with both photonic and magnetic stimuli has been developed by surface imprinting polymerization, where double bonds modified Fe₃O₄ nanoparticles, a water-soluble azobenzene containing 4-[(4-methacryloyloxy)phenylazo]benzenesulfonic acid and bovine hemoglobin (BHb) were used as magnetic core, photoswitchable functional monomer and template protein, respectively. The resultant MIPs possessed a typical spherical structure with a relative rough imprinted layer of 15 nm thickness. Moreover, the MIPs had good binding behavior toward BHb with fast binding kinetics, high adsorption capacity and satisfactory selectivity. The MIPs were proved to be well photo-controlled toward the template protein BHb under the alternating irradiation of 365 and 440 nm: 31.4% BHb was released from the MIPs at 365 nm and 67.2% BHb was bound into the MIPs at 440 nm. As a result, the MIPs were successfully applied to specifically extract template protein from actual biological sample. As a consequence, combining photocontrolled release and uptake, rapidly magnetic separation and specific recognition, the resultant MIPs with photonic and magnetic dual responsive abilities show significant advantages in the enrichment of trace protein in biological samples.