Biotemplate-directed fabrication of size-controlled monodisperse magnetic silica microspheres.

Biotemplating is an effective strategy to obtain morphology-controllable materials with structural specificity, complexity, and corresponding unique functions. Herein we take advantage of the unique heavy-metal-ion biosorption behavior of cyanobacteria cells to fabricate Fe3O4/cell composites. Meanwhile, cyanobacteria cells served as a biotemplate for fabricating solid and hollow magnetic silica microspheres (MSMs). The obtained MSMs retained the original morphology of the cells, and exhibited excellent monodispersity and uniform spherical shape with narrow size distribution. Furthermore, they demonstrated ferromagnetic behavior at room temperature when measured using a vibrating sample magnetometer.