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 Fe₃O₄ labeled as Fe₃O₄-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, Φ_AFP, increases. The enhancements are due to magnetic interactions among BMNPs in magnetic clusters, which contribute extra MH after the association with MH 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.