The Conjugation of Anti-CRP Coated Magnetic Nanoparticle and CRP Antigen Studied by Magneto-Optical Faraday Effect
Yan-shen Lin1*, Chiu-Hsien Wu2, Kuen- Lin Chen1
1Physics, National Chung Hsing University, Taichung, Taiwan
2NanoScience, National Chung Hsing University, Taichung, Taiwan
* presenting author:林延信,
Magneto-optical Faraday effect is a powerful tool to study the interaction between magnetism and light. In this study, we observed magneto-optical Faraday rotation of magnetic nanoparticles (MNPs) by using ac magnetic fields which were generated from a solenoid. The ac magnetic fields applied to samples varied from 10 Gauss to 100 Gauss with a frequency at 813 Hz. The diode laser was used as the light source with the wave length of 532 nm. The MNP fluid of 20 μl was encapsulated in the glass cell with the thickness of 150 μm. The optical responses of the samples were detected by the photo detector and analyzed by the spectrum analyzer. Preliminarily, we observed that the ac output voltages of the photo detector had linear relation with the applied magnetic fields. On the other hand, the Faraday rotation angles of MNPs with different concentrations of 0.03 emu/g, 0.06 emu/g, 0.12 emu/g and 0.24 emu/g were measured. We found that the rotation angle linearly increases with the concentration of MNPs. Furthermore, we measured the conjugation of anti-CRP coated MNP and CRP antigen, and we found that the Faraday angle changes with the clustering of MNPs. With the conjugation of CRP antibody and antigen, the MNPs will aggregate to form larger magnetic clusters. We found that Faraday angle will reach the maximum about two to three hours after the mixture of anti-CRP coated MNP and CRP antigen at room temperature.

Keywords: Magneto-Optical Faraday Effect, Magnetic Nanoparticle