One-step synthesis of superparamagnetic copper alginate gel microspheres (Cu2+-Alg@Fe3O4) using a compression nebulizer

•One-step synthesis of the Cu2+-Alg@Fe3O4 microspheres by atomization.•The Cu2+-Alg@Fe3O4 microspheres with a particle size of 1.0 ∼ 20.0 μm.•The microspheres with a saturation magnetization intensity of 36.85 emu/g.•The copper content in the Cu2+-Alg@Fe3O4 microspheres was 149.2 mg·g−1.•The maximum adsorption amount was 4318.5 mg·g−1. For the application needs of histidine-rich protein separation, this study proposes to prepare a magnetic adsorbent enriched with copper ions and small particle size. Using a compression nebulizer, the magnetic + sodium alginate solution was broken into micrometer-sized droplets and cross-linked and cured with copper ion solution. The magnetic copper alginate microspheres (Cu2+-Alg@Fe3O4) were obtained with an average particle size of 7.1 μm, a magnetic saturation intensity of 36.9 emu·g−1, and a Cu2+ content of 149.2 mg·g−1.The adsorption equilibrium time of the Cu2+-Alg@Fe3O4 microspheres on bovine hemoglobin(BHb) was 90 min, and the maximum adsorption amount was 4318.5 mg·g−1. The Cu2+-Alg@Fe3O4 microspheres also showed stable and good adsorption performance in five cyclic adsorption experiments. [Display omitted]