Characterizations of Anti-Alpha-Fetoprotein-Conjugated Magnetic Nanoparticles Associated with Alpha-Fetoprotein for Biomedical Applications

In this work, we report characterizations of biofunctionalized magnetic nanoparticles (BMNPs) associated with alpha-fetoprotein (AFP) for biomedical applications. The example BMNP in this study is anti-alpha-fetoprotein (anti-AFP) conjugated onto dextran-coated Fe(3)O(4) labeled as Fe(3)O(4)-anti-AFP, and the target is AFP. We characterize magnetic properties, such as increments of magnetization ΔM(H) and effective relaxation time Δτ(eff) in the reaction process. It is found that both ΔM(H) and Δτ(eff) are enhanced when the concentration of AFP, Ф(AFP), increases. The enhancements are due to magnetic interactions among BMNPs in magnetic clusters, which contribute extra M(H) after the association with M(H) and in turn enhance τ(eff). The screening of patients carrying hepatocellular carcinoma (HCC) is verified via ΔM(H)/M(H). The proposed method can be applied to detect a wide variety of analytes. The scaling characteristics of ΔM(H)/M(H) show the potential to develop a vibrating sample magnetometer system with low field strength for clinic applications.