Evaluation of the Magnetization Properties of Magnetic Nanoparticles in Serum Using HTS-SQUID

The magnetization properties of magnetic nanoparticles (MNPs) changed by the action of the buffer and serum solutions with different viscosities were analyzed using dc and ac magnetometers that utilized high-temperature superconductivity-superconducting quantum interference devices. The magnetization properties of MNPs in different solutions with different viscosities were measured using a dc magnetometer via vibrating the sample under a dc magnetic field. The harmonic signal characteristics of the MNPs in different solutions were measured in a low-frequency magnetic field. In addition, the dynamic changes in the magnetic characteristics of MNPs in different solutions were measured using an ac magnetometer with a high frequency. The results corresponding to the low- and high-frequency fields showed that both viscosity of the solvent and the interactions between the MNPs and the solvent are important influencing factors in immunoassays using MNPs.