Fabrication of Fe_3O_4 Nanorods Designed for Liquid-Phase Magnetic Biosensing

摘要

Alternating current (ac) susceptibility-based magnetic biosensing techniques in liquids are promising biomedical applications of magnetic nanoparticles because the methods have a potential for realizing the simple washfree detection of diseases. Controlling magnetic relaxation of nanoparticles is crucial in the biosensing; Brownian relaxation based on the particle rotation in liquids should be dominant to improve the sensitivity. Therefore, we focus on magnetically anisotropic Fe_3O_4 nanorods because it is considered that the particle rotation dominates magnetic response of suspended Fe_3O_4 nanorods due to the shape magnetic anisotropy. In the present paper, the Fe_3O_4 nanorods are fabricated and the dynamic magnetic response of Fe_3O_4 nanorods is evaluated under the liquid phase and the solid phase.