Preparation of polyethylenimine modified molecular imprinting adsorbent with immobilized metal oxides for highly efficient ovalbumin adsorption

In this study, ZIF-based metal oxide molecularly imprinted polymers (ZIF@PEI@TiO2-MIPs) were prepared for efficient and selective separation and enrichment of ovalbumin (OVA) in egg white samples. The effects of pH, OVA concentration, ionic strength, and elution type on the adsorption process were investigated. ZIF@PEI@TiO2-MIPs have rich imprinted sites and large specific surface area. PEI provides a large amount of amino to bind TiO2. As a new type of solid phase extraction adsorbent, ZIF@PEI@TiO2-MIPs can rapidly adsorb OVA and have a large adsorption capacity. The adsorption time is 35 min, and the maximum adsorption capacity is 417.6 mg g-1. The imprinted sites of adsorbent can distinguish the template protein (OVA) from interference proteins, indicating that ZIF@PEI@TiO2-MIPs have good selectivity and adsorption specificity, and the adsorption model conforms to Langmuir adsorption model and pseudo-second-order kinetics. The adsorbent still has good adsorption performance after six adsorption and elution cycles with 0.5% cetyltrimethylammonium bromide (CTAB) as the eluent, indicating its good stability. In conclusion, ZIF@PEI@TiO2-MIPs can specifically identify OVA in complex samples, providing a large possibility for the application of glycoprotein in activities such as biology and clinical practice.