Study of Magneto-Optical Faraday Effect Enhancement in Gold-Coated Iron Oxide Nanoparticles and Application of Alzheimer ''s Disease Detection

• Main Authors: Jian-Ming Chen, 陳建銘
• Other Authors: Kuen-Lin Chen
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/45073739785326359316

碩士 === 國立中興大學 === 奈米科學研究所 === 105 === In this study, γ-Fe2O3 nanoparticles are used as the core and gold were deposited on the surface of γ-Fe2O3 nanoparticles by using the iteration method to form the γ-Fe2O3@Au nanoparticles. The X-ray diffraction (XRD), UV-visible spectrum (UV-vis), superconducting quantum interference device (SQUID), laser diffraction particle size analyzer (DLS), transmission electron microscopy (TEM) and energy dispersive spectrometers (EDS) were used to make sure the gold were actually coated on the γ-Fe2O3 nanoparticles. Then γ-Fe2O3@Au nanoparticles were applied to the detection of tau protein which is associated with Alzheimer''s disease. First, the γ-Fe2O3@Au nanoparticles were modified by functional groups and then the Tau antibody (Anti-Tau) was bind on the surface of gold shell to obtain the detection reagents of Alzheimer''s disease. The magneto-optical Faraday rotation system was used to detect different concentrations of Tau protein. According to previous work, when antibody conjugated with antigen, the magnetic nanoparticles were agglomerated to form larger magnetic clusters. So the angle of Faraday rotation would change during the process. The detection limit of the dextran coated magnetic nanoparticles was 10 ng/ml (10 ppb). In this experiment, we use γ-Fe2O3@Au nanoparticles on which the local surface plasmon resonance (LSPR) can be induced under specific 532 nm laser so that can interact with the magnetic nanoparticles to increase the Faraday rotation angle. The detection sensitivity is significantly improved, and the detection limit of tau protein can reach 1 pg/ml (1 ppt). This method is not only simple but also convient to monitor the combination process in real-time. Our research has a great development potential in early stage detection of Alzheimer’s disease.