One-step synthesis of magnetic carboxymethyl chitosan-copper microspheres with hollow porous structure using a compression nebulizer for adsorption studies of bovine hemoglobin

Superparamagnetic materials are considered to be the main materials for efficient purification of proteins by metal chelating affinity techniques. In this paper, we innovatively propose to atomize a suspension of carboxymethyl chitosan and magnetic Fe 3 O 4 nanoparticles into micrometer droplets using a compressed nebulizer, while collecting and curing these atomized droplets with a container containing copper ion solution. After that, the magnetic carboxymethyl chitosan-copper microspheres(Fe 3 O 4 /CMCS-Cu 2+ ) with hollow and porous structure were synthesized in one step. Characterization of the Fe 3 O 4 /CMCS-Cu 2+ microspheres showed that they were superparamagnetic with a particle size of 1.11 ∼ 2.55 μm. The microspheres were featured with a hollow and porous structure, and the shell layer was covered with irregular pores with pore diameters of 10 ∼ 50 nm. The contents of Cu in the microspheres were 0.0773 g/g. The equilibrium time for BHb adsorption by the Fe 3 O 4 /CMCS-Cu 2+ microspheres under the optimum experimental conditions was 60 min, and the maximum adsorption capacity was 10540 mg/g. The Fe 3 O 4 /CMCS-Cu 2+ microsphere preparation method is simple and efficient.