A pH and temperature dual-responsive macroporous molecularly imprinted cryogel for enhanced recognition capability towards ovalbumin

Abstract

A pH and temperature dual-responsive macroporous protein imprinted cryogel was synthesized by a facile “one-pot” method using N-isopropylacrylamide (NIPAAm) and 4-vinylphenylboronic acid (p-VPBA) as the main functional monomers. The smart molecularly imprinted polymers (MIPs) could recognize the target glycoprotein (ovalbumin (OB) as a template) dynamically and reversibly. The morphologies and features of the cryogels were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The rebinding and swelling experiments showed that the MIP cryogels could respond quickly to temperature and pH. Various parameters such as the pH value of the protein solution, adsorption temperature, and the rebinding time were optimized. Under the optimal conditions, a higher adsorption capacity and imprinting factor of the MIP cryogel were achieved, and were found to be 21 mg g⁻¹ and 3.4, respectively. Moreover, the MIP cryogel exhibited good selectivity and acceptable regeneration capacity. A real sample analysis further demonstrated its feasibility for the target protein separation. These excellent performances suggested that the obtained imprinted cryogel should be a promising candidate for recognition and separation of OB.