2025 Volume 72 Issue 3 Pages 67-72
Using a raw material solution in which nano-sized magnetite particles were dispersed in a silica solution, we synthesized γ -Fe2O3/SiO2 composite fine particles by the spray pyrolysis method. These fine particles consisted of primary particles of about 60 nm in size in which γ -Fe2O3 of about 10 nm was dispersed in a SiO2 matrix, and these primary particles aggregated to form secondary particles of about 1 μm in size. These fine particles exhibited superparamagnetism and had greater magnetic response than commercially available products. In addition, the zeta potential of these fine particles was -30 to -25 mV, the surface was negatively charged, and they had a stronger tendency to adsorb the basic protein such as cytochrome C than the acidic protein such as albumin.
