Improvement of Adsorption Selectivity of Ion-Exchange Chromatography through the Double-Recognition Mode

Ion-exchange chromatography (IEC) was combined with molecular imprinting technology (MIT) to prepare two kinds of double-recognition resins (DEAE@BSA and DEAE@bIgG) using bovine serum albumin (BSA) and bovine immunoglobulin G (bIgG) as the imprinting template proteins. New resins consist of ion-exchange interaction and spatial recognition and were characterized by Fourier transform infrared, scanning electron microscopy–energy-dispersive X-ray spectrometry, thermogravimetric analysis, and Brunauer–Emmett–Teller techniques. The static and dynamic adsorption behaviors of proteins on resins were investigated. In addition, the competitive adsorption between BSA and bIgG was also studied. It was found that the adsorbed protein density (Qc) of the target protein remained the same after imprinting, but the competitive protein dropped obviously. The selectivity factors (α) of DEAE@BSA and DEAE@bIgG could reach 3.56 and 2.56, respectively. The results of adsorption kinetics and frontal adsorption experiments further showed that the dynamic adsorption capacity of target proteins was improved in batch and column modes. Taken together, this study demonstrated that the selectivity of IEC could be improved with the double-recognition mode.