Effects of particle characteristics on magnetic immunoassay in a thin channel

► The effects of size and porosity of particles on magnetic immunoassay in a thin channel were studied. ► Competitive and sandwich reactions of CEA/anti-CEA were studied for CEA detection. ► The detection limits were lower, and the linear ranges were wider than those of literature. ► Magnetic immunoassay in a thin channel has great potential for biochemical analysis and immunoassay-related applications.