Synthesis and cellular compatibility of Co-doped ZnO particles in silk-fibroin peptides

Co-doped ZnO particles were successfully prepared via a facile biomineralization process in the template of silk-fibroin (SF) peptides at room temperature, and SF peptides were coated onto the surface of particles. The ratio of Zn/Co in reactive solution could substantially influence the morphology of as-prepared particles, and the rough spherical particles including some nanoparticles of 50 nm diameters could be obtained at 4:1 ratio of Zn/Co. The saturation magnetization of SF-coated Co–ZnO particles was 8.63 emu/g, much larger than that of Co–ZnO without SF. L929 cell test revealed that the Co-doped ZnO particles had a good cellular compatibility at the concentration of less than 0.25 mg/mL due to silk-peptide coating, indicating that the prepared Co-doped ZnO particles have a potential for the biomedical applications.