Imprinted Fe–Ni double hydroxide nanorods with high selective protein adsorption capacity

Anchoring more template proteins on the carrier surface is one of the most critical steps in the preparation process of protein-imprinted polymers. Inspired by the stable interactions between metal ions and proteins, high external surface iron-nickel double hydroxides (Fe–Ni LDH) derived from metal–organic framework were selected as carriers to develop high-performance surface bovine serum albumin (BSA) imprinted iron-nickel double hydroxides nanorods (Fe–Ni LDH@MIP). A hexagonal hollow structure Fe–Ni LDH was synthesized with nanosheets stacked on the surface by etching MIL-88A with Ni²⁺. The etching of Ni²⁺ increased the surface roughness of MIL-88A and the rough surface of the carrier was conducive to improving the anchorage amount of BSA, thus providing more effective imprinting sites. Controlled coating of the imprinted polymer layer on the surface of Fe–Ni LDH was obtained by aqueous phase precipitation polymerization. The protein adsorption amount reached 329.8 ± 7.8 mg/g in 60 min with an imprinting factor of 2.86. Fe–Ni LDH@MIP also demonstrated excellent and specific recognition ability in the separation of mixed proteins and fetal bovine serum (FBS) and had good adsorption selectivity, whose adsorption capacity only decreased by 11.5% after 7 adsorption–desorption cycles. In short, Fe–Ni LDH@MIP has great potential to apply in the separation and purification of biomolecules. Graphical abstract: (Figure presented.)