Magnetic protein-imprinted micromotors for selective dynamic separation of β-lactoglobulin from milk

beta-lactoglobulin (beta-LG), a strong allergen, is widely present in milk. The separation of beta-LG plays an important role in research on reducing milk allergenicity. In this study, we successfully prepared a magnetic imprinting micromotor driven by decomposing H2O2, which helps to selective dynamic removal of beta-LG in milk processing, thereby reducing milk allergenicity. This micromotor consists of a conductive polymer material called PEDOT/ PSS, which selectively binds beta-LG through its surface imprinting layer. The deposition of the Ni layer gives the micromotor a good magnetic recycling ability, which enables efficient reuse, and the innermost Pt layer promotes the movement of the micromotor through the catalytic decomposition of H2O2, generating O2 bubbles to achieve dynamic and efficient adsorption of (3-LG. In the experiments, the micromotor exhibited excellent kinematic performance in 1.0% H2O2 solution (90-130 mu m/s). Protein adsorption experiments demonstrated the excellent selective adsorption ability of the imprinting layer to the target proteins and the magnetic recycling reuse ability. Its maximum adsorption of beta-lactoglobulin from actual milk samples was 18.8 mu g/mg, the recycling rate is above 90%. Molecular docking experiments elucidated the possible mechanism for the adsorption of beta-LG by the imprinting layer. Processing experiments on real milk samples proved the feasibility of its application in real milk processing. This study combines the advantages of bubble-driven micromotors to accelerate fluid mixing and transfer with the selective adsorption ability of molecularly imprinted polymer layers on target molecules, thus providing a feasible idea for the separation and removal of allergenic beta-LG in milk processing.